Articles About the Sinclair ZX81

Title Description Computers
"All The News Fit to Print" Arctan Computer Ventures offers programs for ZX81/TS1000 users; E. Arthur Brown has exclusive publishing rights to The Hacker’s Handbook; Dungeon of Ymir version three available; Money Machine II available; Soundesign and Tracer available from RMG; replacement SCLDs from Capitol Area Timex/Sinclair Users Group; Tomahawk from Knighted Computers; ROMON for Sinclair QL; Zebra Systems purchased the Sinclair QL, Sinclair ZX81, Timex/Sinclair 1000
"Hello, Z80 Calling..." Looks at ‘ROM calls’ the machine code subroutines stored in the ROM of your computer. They can help keep your Z80 programs shorter, and save programming time and effort. Sinclair ZX81, Timex/Sinclair 1000
16K RAM Pack Schematic Sinclair ZX81
1987 Federal Income Tax Calculator Program to calculate 1987 taxes. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
1K Programs Three, short 1K programs. Sinclair ZX81, Timex/Sinclair 1000
2K Conversion with 6116s ZX81 will accept two 2114 RAM chips or one 6116 RAM, for total of 2K. Sinclair ZX81
2K to 4K RAM Upgrade - An Introduction to ZX/TS Hardware Sinclair ZX81, Timex/Sinclair 1000
3D Monster Maze and Mothership In 3D Monster Maze you are in a maze running from T. (Tyrannosaurus) Rex. The object is to get out alive! Sinclair ZX81, Timex/Sinclair 1000
49 Explosive Games for the ZX81 Review of the book by Tim Hartnell. Sinclair ZX81, Timex/Sinclair 1000
6 Shooter 6 Shooter is a game of skill in which you attempt to hit a randomly moving target. When the target appears in a position which you feel is in your sights, you pull the trigger (hit a key). This causes a bullet to be fired, and, if the target is hit, it disintegrates in accordance Sinclair ZX81
64K RAM Available Mid-March Sinclair ZX81
6K RAM Addition Frustrated by the limitations of 2K RAM, Jim Graham of Oakham, MA, put 6K “under the hood” of his ZX81. He finds it a comfortable compromise, freeing up the edge connector for I/O use. The wirewrapped module consists of four sockets welded together, needs no board modifications and plugs into the existing RAM socket. Sinclair ZX81
8K Machine Code Keyboard Scanning Bernard Puerzer’s program for scanning the ZX80 keyboard (Machine Code Keyboard Scanning Program) was written for the 4K ROM, His program served as the occasion to give the same ability to read the keyboard to 8K ROM users. This required adaptation since the programs are not automatically transferable. One of the problems was to get Sinclair ZX80, Sinclair ZX81
8K Memory PEEK This slow but simple program peeks memory 100 bytes at a time. It displays consecutive bytes in 5 columns by 20 rows. Designed for the ZX81, it works with 16K RAM. Sinclair ZX81, Timex/Sinclair 1000
8K Non-Volatile Memory Kit Review of Hunter board. The Non-Volatile memory (NVM) kit is a battery backup powered RAM board that is primarily designed to fill the transparent address area between 8K and 16K in the Sinclair ZX80/81. The key feature of this product is that with the onboard battery, the routines stored in NVM are retained even with Sinclair ZX81, Timex/Sinclair 1000
8K ROM Monitor Routines Continuation of article from prior issue examining the 8K ROM. Sinclair ZX81
8K Updates Forest Treasure; Defuse; Mastermind; Hangman Sinclair ZX81, Timex/Sinclair 1000
8K/16K Owners Zeta Software of Greenville, SC, now offers 8K/16K program cassettes. Their latest catalog lists a flicker-free scifi adventure and statistical math packages. Sinclair ZX81
A British computer hits it big In the consumer electronics industry, Clive Sinclair is known worldwide as a phenomenally creative inventor whose marketing fiascoes have more than once driven him to the brink of financial disaster. But one month after springing his latest product – a dirt-cheap personal computer called the ZX81 – on the U.S. market, the British entrepreneur finally Sinclair ZX81
A Cheap and Simple EPROM Programmer This article will show you how to build an EPROM programmer. Those interested in peripherals for the Sinclairs (floppy disk, electronic typewriters, etc.) can design monitors and controllers for those devices. Eventually you can program independent microprocessors for special purposes. Sinclair ZX81, Timex/Sinclair 1000
A Keyboard Learning Game New users of the Timex/Sinclair computers sometimes spend a long time hunting for a specific key. The keys that are not used frequently remain hard to find. Keygame is intended to help the user become familiar with the keyboard and to have some fun while learning. Sinclair ZX81, Timex/Sinclair 1000
A Loan Amortization Program This program calculates monthly payments and generates an amortization schedule on consumer loans or home mortgages. The payment tells the user how much of a monthly commitment he is making, and the amortization schedule how much of the payment is being applied to interest and how much to reduce the balance on the loan. Sinclair ZX81, Timex/Sinclair 1000
A Machine Code Graphics Line Drawing Subroutine In the pages of the ZX81 manual, we find a Basic subroutine to draw a line between any two specified points (see Listing 1). However, I found this routine to be exceedingly slow, especially when I wanted to draw several lines on the screen and had to wait several agonizing minutes to get them. The Sinclair ZX81, Timex/Sinclair 1000
A Microcomputer-Controlled Temperature Controller A cheap but versatile microcomputer-controlled temperature controller costing less than $100 is described. The system is built around a Timex/Sinclair 1000/ZX81 microcomputer. This is a truly digital system employing the proportional-integral-derivative feedback-control algorithm, thus making the system capable of producing any required temperature profile at a low cost. Sinclair ZX81, Timex/Sinclair 1000
A Mouthful for Every Occasion You can call up sensational headlines, forceful commands, whimsical statements, ageless wisdom, and irrelevant nonsense all at the push of a key on your Sinclair computer with the Mouthful program. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
A Novice Builds the Sinclair ZX81 One user’s experience building the ZX81 kit. Sinclair ZX81
A Personal Money Management Program When the program has been activated, simply enter income, expense, and loan principal items each month. The computer will then provide you with: An income statement for the current month and the year-to-date. An expense statement for the current month and the year-to-date. A balance sheet showing your various assets, liabilities, and net worth. A Sinclair ZX81, Timex/Sinclair 1000
A piece of cake in Dundee Lynd Church goes to Scotland to discover just how the ZX-81 is manufactured. In keeping with its philosophy of sub-contracting all manufacturing processes, Sinclair Research appointed Timex to produce the ZX-81 when it was introduced in March 1, 1981.  Since that time, production at the Timex plant at Dundee has increased from 10,000 to 60,000 Sinclair ZX81
A Practical Guide to Machine Language Programming on the Timex/Sinclair Using only 16 chapters and 8 appendices, the author takes you on a guided tour of the Z80 in Sinclair country, distinguishing the CPU properties from the system behavior with clarity and flair. Your tour guide is an expert whose practical experience includes writing the word processor “WORD*” on which this book is written. Appendix Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
A Program to Index Articles Program lets you index and instantly find articles from your favorite publications by name, category, volume, issue and page. Sinclair ZX81
A Regulated-Voltage Power Adaptor Schematics to build power supplies for the ZX81. Sinclair ZX81
A Small Business Payroll Program Every business with paid employees has the complicated task of doing its payroll. The program in this article will provide accurate payroll information for up to 35 employees. If the number of employees is greater then 35, the list can be broken down into shorter lists and the results combined where needed. Sinclair ZX81, Timex/Sinclair 1000
A Tool to Help Debug Programs To determine what occurs during a loop portion of a malfuntioning program, use a PRINT statement called a flag. Sinclair ZX80, Sinclair ZX81
A Z80 machine language program to use the ZX81 as an audio frequency counter Sinclair ZX81, Timex/Sinclair 1000
ABC-123: Educational Games for the ZX81 The “ABC/123” program is quite long, so we are breaking it into two parts. The result of this first installment will be a self-sufficient program in its own right. It is a trainer in the recognition of the alphanumeric characters, both upper and lower case. Sinclair ZX81, Timex/Sinclair 1000
Across the Pond Inaugural column about the American side of the Sinclair world. Gives a brief overview of Sinclair history in America, discusses marketing of the TS 1000, introduction of the TS 2000 and eventual launch of the TS 2068. The ZX printer could not pass the requirements of the Federal Communications Commission, so Timex contracted with Alphacom Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Across the Pond Comparison of market in UK to that in US, especially after the departure of Timex Computer Corp. Despite official support, Timex users persist and an “underground” support scene exists. Discusses MSCRIPT, commissioned by Timex from Micro-Systems for the 2068, available from 21st Century Products, and Zebra Systems’ drawing package for use with their adapted Koala Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Across the Pond Updated version of MSCRIPT; now returns to BASIC for file save/load. Feature added by Zebra. Greeting Card Designer from Zebra. ZPRINT-80, also from Zebra, supports Aerco, both Tasman, and A&J interfaces with LPRINT, LLIST, COPY. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Across the Pond Overview of telecomputing and bulletin board options, including Zebra’s bulletin board. Modem options for QL covered. Softsync’s shift to IBM noted, as well as Nigel Searle’s role in the company. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Across the Pond Report on the Second Annual Midwest Timex Sinclair Computer Fest. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Across the Pond Spectrum ROM options and Z-link, a twister board, are discussed. DAMCO Enterprises’ Rainbow Plus Interface, which is both twister and ROM that keeps the cartridge slot free. Several vendors are importing products from UK sources. Mass storage options for the 2068 are available from AERCO, Ramex International, A & J Microdrive and Zebra Systems. Zebra Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Across the Pond Describes Spectrum emulator ROM options from Doug Dewey (EMU-1 and EMU-2), Bill Russell (Romswitch), need for a twister board (like the Z-Link) to use Spectrum bus devices like microdrives or Wafadrive, and the A & J Microdrive that plugs directly into the 2068. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Across the Pond: Telecomputing across the U.S. T/S 2050 modem; bulletin boards. Zebra Systems ran a BBS in 1985; customers could place orders through the BBS. Online services like MCI Mail, Compuserve, The Source are discussed. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Adapting the ZX81 Rampack to the TS2068 Adapt the 1016 ram pack, memory mapped to the DOCK bank. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Add a Full Size Printer to Your System Overview of printer interface options for the TS1000/ZX81. Sinclair ZX81, Timex/Sinclair 1000
Add an RS-232 Port to Your ZX81 Shows how to add a standard communications interface to the ZX81 – an RS-232 serial communications port that will let you access standard printers, modems, and other computers. Sinclair ZX81, Timex/Sinclair 1000
Add Direct Video Output to Sinclair ZX81 Simple schematic to provide monitor video out. Sinclair ZX81
Adding A Joystick To The Timex-Sinclair 1000 Adapt an Atari joystick to emulate the arrow keys. Sinclair ZX81, Timex/Sinclair 1000
Adding a Joystick to Your ZX81 Wire a joystick to map to the arrow keys. Sinclair ZX81, Timex/Sinclair 1000
Adding a Video Monitor to your Sinclair ZX81 Simple diagram for tapping off the signals going into the RF modulator. Sinclair ZX81, Timex/Sinclair 1000
Adding Feet and Inches The program assumes the following conventions: dimensions are entered in feet, inches and eighths. Fractions involving sixteenths and beyond are not used. A dimension 12″ or larger is expressed in terms of feet and inchies. For example, 16″ is expressed as 1’4″. Sinclair ZX81, Timex/Sinclair 1000
Adding On To Gladstone Many memory expansion boards have been offered for ZX81’s and TS1000s. One of the first to break down through the $100 price barrier was the Gladstone 64K RAM pack. It gave you use of RAM memory from locations 8K through 64K. Its only short coming was that you had to ALWAYS use all of the Sinclair ZX81, Timex/Sinclair 1000
Adventure A Adventure is not for impatient or unimaginative players. It has no bombs, no graphics, and no split-second decisions. It is an intellectual game requiring thought rather than reflexes. Sinclair ZX81
Alien Treasure In Alien Treasure two kinds of treasure are scattered over the surface of a planet far from earth. Your ship has landed, and you have sent out your robot searcher which you guide from your control room. The field of search shows on your ZX81 as a full screen display. The treasure is marked by Sinclair ZX81, Timex/Sinclair 1000
All about ROMs Review of Understanding your ZX-81 ROM by Ian Logan. Sinclair ZX81
An Assortment of Sorts Several sorts implemented for the 1000: bubble, float, shell and quick sorts. Sinclair ZX81, Timex/Sinclair 1000, Downloadable
An inexpensive computer and interface for research in the behavioral sciences The Sinclair ZX81 computer and Byte-Back BB-1 control module are very inexpensive devices that can be used to control equipment in a psychology laboratory. A simple program and description for interfacing the system to a Skinner box are presented. MicroAce, Sinclair ZX81
An Introduction to Expression Evaluation In the Sinclair 8K ROM program of the ZX80/81 the “expression evaluator” is to be found at 0F55-111Bh (improved 8K ROM) and forms an essential part of the program. A study of the fundamental parts of the “expression evaluator” can be very useful as it enables Basic programmers to understand many of the limitations and Sinclair ZX81, Timex/Sinclair 1000
An Introduction to Machine Code The ZX80/1 microcomputer system as supplied by Sinclair Research is capable of being programmed in two different languages, i.e., Basic and Machine Code. Sinclair ZX80, Sinclair ZX81
An Introduction to Machine Code How to start using machine code on the ZX80/81. Sinclair ZX80, Sinclair ZX81
An Introduction to VU-CALC Spreadsheeting for the Timex/Sinclair 1000 and the Sinclair ZX81 Review of the book. Sinclair ZX81, Timex/Sinclair 1000
An Inventory System Mass data storage is accomplished more efficiently by a disc system than by a cassette recorder. However, until such a system is available for the ZX80/1 computers, Sinclair owners will have to rely on the cassette system. This article offers a program for a modest inventory system based on the 8K ROM and 16K RAM. Sinclair ZX81
An Updated ZX81 Description of a 1000 with internal 64K, a “serial data port” and other mods. Sinclair ZX81, Timex/Sinclair 1000
Analog-Digital Converter Use with the BB-1 I/O board. Converts at 2.5v and 5v to 8 bit values (0-255). Sinclair ZX81
Annuity Program calculates the payments needed to pay off a loan or how many years it takes to pay off a loan at a fixed payment. Sinclair ZX81
Another $100 Misunderstanding Tips for constructing the ZX81 kit. Sinclair ZX81
Another Look at 450ns EPROMS vs the ZX81/TS1000 Paul Hunter’s comments on using 450ns EPROMs on ZX/TS computers (May83) strike me as true but incomplete. Paul shows how to add a flip-flop to delay the computer by inserting wait states and thus make the computer read slow EPROMS. You can use another chip select scheme to cure access problems without adding circuitry or Sinclair ZX81, Timex/Sinclair 1000
Another Printer Tip: ZX81/TS 1000 Sinclair ZX81, Timex/Sinclair 1000
ANOVA programs for Timex/Sinclair 1000, 1500, and ZX81 microcomputers Eleven statistical programs for the Timex/Sinclair 1000, 1500 and ZX81 microcomputers are listed and described in a 167-page book. The programs can run relatively large data sets using less than 16K of memory. Accurate calculations are performed with difference formulas and provisional mean formulas. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Applied Sinclair: Subroutines for the Mathematically-Minded This publication is, in a word, “impressive”. To complement his powerful cadre of subroutines, which are capable of handling some rather formidable problems from applied math, Booth has also included some very elegant plotting routines, which, used in conjunction with the numerical programs through a (simply written) main program will actually plot the solution for Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
Archaeological Research Using the ZX81 With slight modifications, this program can be adapted to other categories of archaeological data such as pottery, artefacts, or settlement research. The possibilities of the ZX81 are not exhausted by this program. Among other things, the high resolution capabilities of the ZX Printer enabled us to write a program which generated user-designed characters, in our Sinclair ZX81, Timex/Sinclair 1000
Arithmetic Series Quiz One exercise to sharpen arithmetic skills is to use a series of numbers which require discerning the relationships of the numbers in order to complete the series. The program in Listing 1 will print out an arithmetic series. Your task is to figure out the next two numbers in the series. If you are not Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Arithmetic with a Smile The computer as an instructional tool is perhaps nowhere more successful than in conducting arithmetic practice drills. Unlike the typical classroom teacher, the computer never tires and never makes a mistake. It provides arithmetic practice and never forgets to reward a right answer with a smile. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Artillery with Motion Improved version of Artillery. Sinclair ZX81
As Easy as 2+2 Ever thought about learning to program in machine code? Maybe you have. Maybe you even got far enough to open one of those thick books full of jargon and technical details. Maybe you got far enough into it to be scared away. Sinclair ZX81
Astronomical Algorithms on the ZX81 Examples of astronomical algorithms from More Uses for Your Timex/Sinclair 1000: Astronomy on Your Computer. Sinclair ZX81
Audio Frequency Counter Program for the Timex/Sinclair ZX81 This program will run with as little as 1K of RAM and will allow frequency measurements of up to 28,500 Hz. This is useful for tuning RTTY tone generators, electronic musical instruments, tone encoders, and for calibrating audio generators. The audio signal is fed to the computer’s earphone jack, and the frequency is displayed to Sinclair ZX81, Timex/Sinclair 1000
AUDISY 65 byte machine code routine that allows you to digitize and store the data for any sound phrase on your ZX/TS computer with 16K RAM. Sinclair ZX81, Timex/Sinclair 1000
Awari Awari is an ancient African game for two players. Six piles of three stones each are arranged in front of opposing players, with each player’s “home” to the right of the piles. The play consists of taking all the stones in one of the player’s piles and, moving counterclockwise, dropping one stone in each pile Sinclair ZX81, Timex/Sinclair 1000
Back-up system for data Short overview of the ZX-99 RS232C and tape control system. Sinclair ZX81, Timex/Sinclair 1000
Backgammon Reviewed Review of the machine language game from Biocal Software. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Banners on the TS-2040 Program to print banners lengthwise on the 2040. Sinclair ZX81, Timex/Sinclair 1000
Bar Chart Bar Chart uses the 8K PLOT function to simplify the bar chart algorithm. It assumes B(15) has been filled, or partially filled, with values between 0 and 2000. Sinclair ZX81
Basic Computer Programs for Business, Vol. 1 While visiting a favorite book store, I discovered a treasure chest of jewels suitable to adorn the ZX80/81. This book offers “over 35 programs covering budgets, depreciation, cash flow, property comparisons, accounts payable, order entry, warehouse locations, inventory turnover analysis, job routing, resource allocation, production scheduling,” just to name a few listed on the cover. Sinclair ZX81
BASICare Offers ZX81 Megabyte Memory Decoding BASICare of London introduced their Organic Micro system for ZX81s. Sinclair ZX81, Timex/Sinclair 1000
Basil's Compendium: LET A= ... This installment will teach you how to enter an actual program in machine code. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Basil's Compendium: Where to Put the Program This chapter will list some requirements for the place where we will put the machine code, and will show you how to find a memory location that meets those requirements. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Beginner's Basic -- INKEY$ Function The INKEY$ function, though more obscure than commands like SAVE and RUN, is simple to use and adds a nice touch to your programs. Sinclair ZX80, Sinclair ZX81
Beginners - Analyzing the Problem The first step in solving a problem with a computer is analyzing how you would solve it without one. Sinclair ZX80, Sinclair ZX81
Beginners: User-Friendly Programs Some easy programming methods to write user-friendly programs for either 4K or 8K ROM programs. Sinclair ZX80, Sinclair ZX81
Beginners' Basic: Getting Information into Your Computer Introduction to variables. Sinclair ZX81
Beginners' Column: REM Revisited Storing machine code in REM statements. Sinclair ZX80, Sinclair ZX81
Beginners' Dimensioned Arrays Although BASIC uses simple English commands, the DIM statement is one of those that takes a little explanation. Sinclair ZX80, Sinclair ZX81
Beginners' ML -- Register to Register Examines the loading, adding and subtracting instructions. Number 5 in series. Sinclair ZX80, Sinclair ZX81
Beginning Programming: ZX81 Math Article expands on bits, bytes and binary numbers over the ZX81 and TS1000 manual. Sinclair ZX81, Timex/Sinclair 1000
Best of Sync, Volume 1 Review of the book that collected articles from the first year of Sync magazine. Sinclair ZX80, Sinclair ZX81
Biorhythms I wrote this program as a result of a great disappointment I experienced after purchasing a Biorhythms program from one of the prominent software companies. The program did not print an accurate set of curves, and did not print a mathematically correct result. Sinclair ZX81, Timex/Sinclair 1000
Bit by Bit Machine language tutorial. Sinclair ZX81, Timex/Sinclair 1000
Blast Effects on ZX81 Subroutine simulates laser, cannon shot and other effect used in arcade-type games. Sinclair ZX81, Timex/Sinclair 1000
Block Transfers: Horizontal Scrolling on your 1K ZX81 A programming technique called block transfers of memory adds new possibilities for your programming and for taking advantage of your computer’s capabilities. Although the technique involves the use of machine language, this article assumes only that you are familiar with the Sinclair manual ZX81 BASIC Programming and that you are willing to work with hexadecimal. Sinclair ZX81, Timex/Sinclair 1000
Block Transfers: Variables Transfer (Part 2) One drawback of Timex/Sinclair computers is that LOADing a program erases any data that you have in the variables area to make room for in-coming variables. However, the program developed here allows you to keep variables in the machine safe from NEW, CLEAR, and LOAD. Furthermore, it allows you to transfer variables from one Basic Sinclair ZX81
BOLEX: Beginner's Ohm's Law EXercises BOLEX is a program that solves Ohm’s law equations two at a time. Enter the program into your computer, hit RUN and NEWLINE. Four prompts will appear on your screen: amps, volts, ohms, and watts. Type in a value for one, hit NEWLINE. Continue until the values have been entered. With two values you will Sinclair ZX80, Sinclair ZX81
Book Review: Your Timex/Sinclair 1000 and ZX81 Sinclair ZX81, Timex/Sinclair 1000
Break the 1K Barrier Double the ZX81 RAM to 2K with a 6116 static RAM. Sinclair ZX81
Breakeven Analysis This program requires only a single video format for all control data input with an option to erase and re-enter data. This option occurs just before computation, which doesn’t begin until you approve data entries. Sinclair ZX81, Timex/Sinclair 1000
Brick Buster “Brick Buster” is a game in which the player earns points by knocking out as many of the bricks in the playing area as possible. On-screen scoring and a high score memory are provided for competitive playing. The active part of the game is written in machine code for fast action. The rest of the Sinclair ZX81, Timex/Sinclair 1000
Bridging the Gap Between Sinclair & IBM I finally got my hands on an IBM PC. After having worked on a main frame for so long, I found the IBM to be a pleasant experience. I also discovered that the file system on the IBM was similar to that of the main frame— though much slower. Since I was still hacking away Sinclair ZX81, Timex/Sinclair 1000
British company announces inexpensive computer: The Sinclair ZX81 will sell for $149.95 Sinclair Research, Ltd., a British company that makes the low-cost zx80 personal computer, has announced its latest model, the ZX81. It is an eight-bit, Z80A-based machine with 1K static memory and 8K ROM. It costs $99.95 in kit form and $149.95 assembled. Sinclair has recorded 1000,000 unit sales since it introduced the machin in Britain Sinclair ZX81, Timex/Sinclair 1000
Building Heat Load This article gives a program for calculating your building heat load. You may not find all the answers, but you can get a preliminary comparison of some of the options. The program is designed to find the heat load by solving two equations. Sinclair ZX81
Bytesavers Hint If you are using a PRINT after a line number simply to add an empty line, use two commas instead. Sinclair ZX80, Sinclair ZX81
CAI Printer Update CAI Instruments will offer software components to make their Widget printer compatible with both 4K and 8K ROMs. Sinclair ZX80, Sinclair ZX81
Calculating the Days Knowing the number of days between two dates is frequently necessary for calculating interest, apportioning expenditures, or calculating average use of items. We are also interested in the more trivia type questions such as how many days before an important date, how many days between certain historical dates, and even how many days we have Sinclair ZX81
Cardioid Plot Plots a heart-shaped curve. Sinclair ZX81
Cassette LOAD/SAVE Routine and Problems for the ZX81 Sinclair ZX81, Timex/Sinclair 1000
Cassette LOAD/SAVE Routine and Problems for the ZX81, Part 2 Sinclair ZX81, Timex/Sinclair 1000
Cassette LOAD/SAVE Routine and Problems for the ZX81, Part 4 Compilation of articles/resources on load/save issues. Sinclair ZX81, Timex/Sinclair 1000
Cassette LOAD/SAVE Routine and Problems for the ZX81, Part 5 Sinclair ZX81, Timex/Sinclair 1000
Catch A Dragon! Program to plot “dragon curves.” A dragon curve is a regular fractal which forms from an infinitely repeated construction process. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Chaining Programs A method for merging programs. The method in outline is: 1) Protect the resident program from erasure by POKEing a copy of it above RAMTOP. This area of memory, once created, is unaffected by LOAD, SAVE, and NEW. 2) LOAD the other program from the tape in the normal manner. 3) POKE the original program Sinclair ZX81, Timex/Sinclair 1000
Changing a REM Statement from ZX81 BASIC This is an editor in BASIC that works much like the m/c LDOS editor for entering an LDOS command line. Sinclair ZX81, Timex/Sinclair 1000
Chase Chase is a game of survival. The object is to survive as long as you can. You are set in a playing field, shown as a 20×10 block on your TV screen, surrounded by a lethal fence. Mines are scattered about in the field. You are being chased by five robots which will move straight Sinclair ZX80, Sinclair ZX81
Checkbook Balancer: Old Standby Reviewed Program that comes with a keyboard overlay to help balance a personal checkbook account. Sinclair ZX81, Timex/Sinclair 1000
Checkbook Management A computer with its TV display, makes the task of updating and balancing a checkbook simpler than using a four-function calculator. The display enables the user to double-check entries and so helps eliminate mistakes. In addition, if mistakes are made, they are easily corrected. Below are two programs which I developed for these purposes. Each Sinclair ZX81
Circuit Circus Excerpted from SWYM Newsletter, Seattle Sinclair Users Group. Sync inverter for QL, load fix for ZX81/TS1000, TOS power supply, modem power. Sinclair QL, Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
CKTYPE 1000 (Machine Code Version) Machine code version of Stan Lemke’s program. Sinclair ZX81, Timex/Sinclair 1000
Clarification of Bytes Remaining Ian Logan’s 8K Bytes Remaining program, Dec. 81, uses function keywords for all input except E, the numbers, and the punctuation. Thus after 1 REM type the letter E, the numeral 0, the function RND, the function LN, the function arcosine, a colon, and so on. The only space you type in is 1 after Sinclair ZX81
Clear That Screen! The purpose of this article is to present some alternatives to this command, and in this process maybe show some ways of handling your display file. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Clive Sinclair of Sinclair Research Trying Again in Consumer Electronics The British, it is said, are great at designing a product but awful at exploiting it. In earlier eras, for example, much of the original work on the jet engine, the computer, radar and the early work on semiconductors was done in Britain. But the money on them was made elsewhere. Clive Sinclair seems living Sinclair ZX80, Sinclair ZX81
Code Transfer: ZX81 Sinclair ZX81, Timex/Sinclair 1000
Comet Crusher Astronomers have spotted a hitherto unknown comet a million kilometers from the earth. Calculations indicate that it will collide with the Earth’s atmosphere at a shallow angle and will probably break up into many pieces. Each of these pieces could destroy a city. Top scientists have advised placing special Comet Crusher missiles at strategic locations Sinclair ZX81
Computer Battlegames and Computer Space Games Computer Battlegames and Computer Spacegames share the same format. The heart of each book consists of listings of about a dozen short games. Each listing is designed co work on a ZX81 or Timex Sinclair 1000, but “translations” are included for the Spectrum, BBC micro, TRS 80, Apple, and Vic 20. There are also brief Sinclair ZX81
Computer Keyboards Professional Keyboard Kit and Enclosure for ZX81 Review of Gladstone’s keyboard and enclosure. Sinclair ZX81, Timex/Sinclair 1000
Computers for Kids -- Sinclair ZX81 Edition Review of the Creative Computing Press book. Sinclair ZX81, Timex/Sinclair 1000
Consumer Electronics Show wows Vegas Sinclair brought the ZX81 to the show, even though the company does not and will not have a dealer network. Mary Reinman of Sinclair said the company was at CES to get exposure and allow company leaders to meet with others in the industry. Sinclair ZX81
Copter Short program. Sinclair ZX81, Timex/Sinclair 1000
Creating a Four Port Expansion Decoder Memory-mapped IO for the 1000 computer. Sinclair ZX81, Timex/Sinclair 1000
Crossing the Asteroid Belt You are the pilot of a space ferry going back and forth through the asteroid belt. This calls for highly skilled navigation to avoid hitting or being hit by the asteroids. Sinclair ZX81
Crypto This sophisticated coder and decoder runs in only 2K. Use it for fun as a stand-alone program, or create a subroutine to make your datafiles unintelligible without the keyword. Sinclair ZX81, Timex/Sinclair 1000
Curing 16K RAM Random Dumping Suggestions for eliminating RAM pack wobble. Sinclair ZX81
Curve-plotting Graphics Curve-plotting has many applications. For example, an oscilloscope is a curve-plotting device which allows the user to view time-varying voltages. This article presents a program which allows the Timex/Sinclair computers to be used as curve-plotting devices. The common representations of curves possible with this program include the following: Cartesian, Cartesian Parametric, polar, and polar parametric. Sinclair ZX81
Cyborgwars Cyborgwars is a strategic game in which four warring cybernetic empires each call upon a human leader to take control and become the supreme leader. This game is the managing an economy, resource allocated type. The resources, in this case, are the robots themselves. The empires are based on a hierarchy of robots: breeders, farmers, Sinclair ZX81, Timex/Sinclair 1000
Dateline:Tomorrow: Naked MicroAce On the Way. Also ZX81 We hear that the MicroAce II will be announced shortly. It will have a full-stroke keyboard, possibly 16K of on-board memory, will run 8K ZX80 Basic, but will not have a case or housing. According to insiders at MicroAce, it is a much improved machine and allegedly better than the recently introduced ZX81 by Sinclair/England. MicroAce, Sinclair ZX81, Timex/Sinclair 1000
Dear Editor TS2068 version of Dave Wood’s High Line Numbers; maintaining the ZX81; questions about TS2040, TS2068 and TS1500. Sinclair ZX81, Timex/Sinclair 1500, Timex/Sinclair 2068
Dear Editor Problems with vendors; VU-CALC with larger memory units; expanding memory space; memory problems with a 2040 printer; monitor problems with 2068. Sinclair ZX81, Timex/Sinclair 2068
Dear Editor Cassette recorders; speed with 16K; jumping to program lines quickly; handling negative numbers; wirewrap edge connectors; replacing cassette jacks; techniques for saving memory variable space. Sinclair ZX81
Dear Editor ZX-Microfair in London; Microace 8K ROM has bugs; Microace regulator; floating point in 8K ROM. MicroAce, Sinclair ZX80, Sinclair ZX81
Dear Editor How to make a program unlistable; program for linear regression; painting heatsinks; FORTH; problems with 8K ROM/keyboard upgrade for ZX80; MicroAce flicker-free kit; large keyboard; edge connector cleaner. MicroAce, Sinclair ZX80, Sinclair ZX81
Dear Editor Sinclair discontinues tech support. Inventory control program sought. Connect full size keyboard to ZX81. Improving ZX80 cooling. Sinclair ZX81, Timex/Sinclair 1000
Dear QTS Sheingorn runs part of his clinical practice on a ZX81; Bower purchased a 2068 to do freelance bookkeeping and writing; Freeline submitted a program that turns a directory listing into a program loader. Sinclair ZX81, Timex/Sinclair 2068
DEF on the Sinclair One way around DEFine in Sinclair Basic is to replace all FN calls with the expression in the definition. This often requires breaking down an equation to simplify it. Sinclair ZX81
Defective 8K ROMs Defective ROMs and notes about power converter in 16K RAM pack. Sinclair ZX81
Defensive Awari Improvements to author’s program. Sinclair ZX81
DEFMAG 29 byte machine code routine that allows you to store audio frequency data and to synthesize the facsimile sound at will. Sinclair ZX81, Timex/Sinclair 1000
Degrees, Grads, and Radians There are three methods of measuring angles: degrees, grads, and radians. However, the ZX81 with all its new trigonometric functions can only measure angles in radians. You can convert a measurement by any of the three methods to either of the remaining methods with the few short programs given in the listings below. You may Sinclair ZX81
Deleting Blocks of Basic Statements Simple routine to delete a block of lines. Sinclair ZX81, Timex/Sinclair 1000
Demand for ZX81 Outstrips Supply Sales have been at 1000 units a day and world-wide sales in October are reported at 40,000. Gladstone Electronics, who import the ZX81 direct from Britain placed the first order from North America but still have an enormous backlog of orders. Sinclair ZX81
Dense Pack Basic, and the use of Logical Operators There has been a considerable amount of questions and interest about Dense Pack programming techniques andt the use of Boolean logic. This article written in 1983 by Sharon Aker merges nicely with my feeble attempts to explain the use of Boolean Logic in Basic programming. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
Developing a Memory Map Consensus Nick Lambert of Quicksilva proposed that suppliers for the Sinclair computers reach a consensus on some kind of memory map to avoid “a whole heap of problems” to everyone’s benefit. He proposed a ZX Computer Memory Map on a provisional basis for discussion. Sinclair ZX81
Diagonal Lines You can make 45 degree angles with two nested FOR-NEXT loops. Sinclair ZX81
Dice and Train Dice strictly speaking is not a game. By simulating the throw of a pair of dice, the computer calculates the distribution of the number of throws entered according to the number of spots the dice show. Be prepared for a wait if you enter a number like 5000. Train likewise is not exactly a game, Sinclair ZX80, Sinclair ZX81
Dice Roller Implementing polyhedral die roller routines in C with Z88dk. Sinclair ZX81
Digital Clock This program operates as a digital clock, showing A.M. or P.M. and changing at 12:00. Sinclair ZX81
DIM as Calculator Sum-to-Memory DIM arrays can function as a sum-to-memory system found in many calculators. More importantly, it acts as a counter function and can be used where FOR-NEXT loops will not work. Moving Billboard, this illustrates the counter function. Sinclair ZX81, Timex/Sinclair 1000
Double Your Memory Although the ZX81 was designed to be inexpensive, a foresighted designer has provided the circuitry to use a 2K x 8 bit static RAM on the circuit board. Sinclair ZX81
Drawing a Line Code that implement’s Bresenham’s line algorithm in C and BASIC for the ZX81. Sinclair ZX81
Edge Connectors Available Kopak Creations of New York now offers 46-pin edge connectors for ZX80/81s. Sinclair ZX80, Sinclair ZX81
Editor's Notebook: Report from Chicago CES Sinclair announced ZX-81 at the event. Sinclair ZX81
Educational Software Vendor Edson Electronics offers educational programs for ZX80/81. Sinclair ZX80, Sinclair ZX81
Elimination Elimination is a traditional dice game which provides a worthwhile vehicle for teaching young children (and others) simple strategy, an understanding of odds, and the mental manipulation of numbers. Consequently, it helps reinforce arithmetic skills since the player’s ability to use mental arithmetic is pitted against the computer’s problem posing ability. Although the game is Sinclair ZX80, Sinclair ZX81
Enjoying Your Computer: Games Games available for Sinclair computers. Sinclair ZX81, Timex/Sinclair 1000
Entrapment This game pits you against your computer. Sinclair ZX81
Exchanging Registers, Part 6 In addition to the eight registers A,F,B,C,D,E,H and L covered in an earlier article, the Z80 (central processing unit in your ZX80/81) has a twin set of alternate registers. Sinclair ZX80, Sinclair ZX81
Expand Your Timex/Sinclair Operating System Expansion card with 8K of battery-backed CMOS RAM in the 8-16K range. Part two. Sinclair ZX81, Timex/Sinclair 1000
Expand Your Timex/Sinclair Operating System Expansion card with 8K of battery-backed CMOS RAM in the 8-16K range. Part one. Sinclair ZX81, Timex/Sinclair 1000
Expand Your ZX-81 Memory to 32K Translation of article from ZX-TEAM-MAGAZIN. Sinclair ZX81
Expanding Existing 16K Programs If you upgraded to 48K RAM for your ZX81, you may think it simple to add a few program lines and enlarge the variable arrays in existing 16K RAM programs to utilize the increased memory capacity. Sinclair ZX81
Exploring the Timex/Sinclair 1000's Sinclair Logic Chip (SCL) Attempts to reverse engineer the ULA via disassembly of ROM. Sinclair ZX81, Timex/Sinclair 1000
Exploring the Timex/Sinclair 1000's Sinclair Logic Chip (SCL), Part 2 More exploration, including some circuit sketches. Sinclair ZX81, Timex/Sinclair 1000
Extended Basic For The TS1000/ZX81 Review of Thomas Woods’ Extended Basic. It is an extension/BASIC interpreter which lives in a 3.5K long 0 REM statement. All commands are entered after an initial REM statement on a line; multiple statements can be entered with a colon. Sinclair ZX81, Timex/Sinclair 1000
Extensions to Basic USR routines to invert every character on the screen, print bytes of free memory, create an inverse program listing, and simulate READ, DATA and RESTORE. Sinclair ZX81, Timex/Sinclair 1000
EZUG Newsletter The Educational ZX80/1 Users’ Group (EZUG) publishes a newsletter each month for ZX80 users. Sinclair ZX80, Sinclair ZX81
Filler Up: For the TS 1000/ZX81 Have you ever had a use for a partial screen clear or a rapid screen fill with a specific character? Then FILLER UP is for you. It’s a short (24 byte) machine code routine that can be stored in an opening REM statement or relocated to any of your favorite M/C storage spots (no absolute Sinclair ZX81, Timex/Sinclair 1000
Find Clean Tape on 8K Quickly find the unused section of tape for SAVEing 8K programs on multi-program tapes on any RAM size. Sinclair ZX81
Firstloader -- From ZX/TS to 2068 Syntax commissioned a custom program, written by David Ornstein, to convert your existing programs for the 2068 or 48K Spectrums. This program translates input bytes from ZX/TS tapes to an equal number of output bytes in your 2068 that you must edit, and then save. Codes & program control structures differ in the two designs, Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068, Downloadable
Flashing Prompts Subroutine Sinclair ZX81
Flight Simulation Flight Simulation puts you at the controls of an airplane in midflight, and your objective is to navigate to the airport and land. This is something like saying your objective in pinball is to keep the ball in play: not as easy as it sounds. Review of the Gladstone Electronics program. Sinclair ZX81
Follow our golden rules for better SAVEs and LOADs Tips for saving and loading. Sinclair ZX81, Timex/Sinclair 1000
For Your Information: Tidbits About CP/M, TS/TC2068, TC2048, ZX81, TS1500 and QL Sinclair QL, Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
For Your Sinclair: New Releases External keyboard for TS2068, sound booster, RGB interface and cartridge adaptor from John Mathewson. Utility tape for TS1000/ZX81/TS1500 from LST Software. PC-DRAW from MDM Enterprises. Compuserve announces GIF format. Desktop publishing program from Charles Stelding. Hardware/software to print to Commodore 1520 plotter. Archive utilties for QL. Sinclair QL, Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
For Your Support Product announcements from Robert Fischer, UAS, Tom Laffin, Knighted Computers, RAMEX, Ben Johnson, Fred Nachbaur, Tom Bent, Jim Houston Enterprises, Paul Bingham, Sum-Ware and Ray Kingsley. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
For Your Support Product announcements from G. Russell Electronics, Byte-Back, Variety Sales, Chia-Chi Chao, Larken Electronics, Sams, Fred Nachbaur, Lemke Software Development and E. Arthur Brown. Sinclair QL, Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Four-digit Multiplexed BCD to ZX81 Adaptor Interface binary-coded decimal (BCD) devices to the ZX81. Sinclair ZX81
From The Editor's Cluttered Desk Themed issues; where to get your computer fixed; computer in business; Maryland doctor uses ZX81; Brazil’s TK 90X; Fred Nachbaur, QL’s price hits rock bottom; more QL news from the UK; Sir Clive’s Z88 update; dates to remember. Cambridge Z88, Sinclair QL, Sinclair ZX81
Game cassette for Timex/Sinclair 1000 or ZX81 Reviews of Gamestape 1, 2, 3, 4 and 5 from Melbourne House. Sinclair ZX81, Timex/Sinclair 1000
Getting Acquainted with Your ZX81 This British book is a good way to move beyond the ZX81 manual if you’re new to computers. Sinclair ZX81, Timex/Sinclair 1000
Glitchoidz Report Corrections to Search and Replace (4:1), Brick Busters (4:1) and Tax Shelter Time Bomb (4:1). Sinclair ZX81, Timex/Sinclair 1000
Glitchoidz Report Corrections to GRA+PIX; Mini-Billboard; The PEEK Function and POKE Command; An Inventory System; The Hidden Chessmen. Sinclair ZX80, Sinclair ZX81
Go-fer Review of sophisticated data base system that supports cassette and disk drives. Sinclair ZX81, Timex/Sinclair 1000
GRA+PIX: A System for Pixel Graphics The following article describes a set of subroutines for drawing lines, arcs, regular geometric shapes, and sectors on the Sinclair ZX80 with the 8K Basic ROM and 16K RAM. The routines should also work on a ZX81 with 16K RAM. In addition, in SLOW mode on the ZX81, you can watch the figures develop as Sinclair ZX81
Graphing Capabilities for TS1000 (ZX81) Product announcement for Data Storage and Display System from ZX-Panding. Sinclair ZX81, Timex/Sinclair 1000
Hangman The old game of Hangman can also be played on your ZX80. The program listed below preserves not only the battle of wits between the two players, but also draws on the graphics capabilities of the ZX80 to draw the figure for you. The program with full prompts on the screen requires over 1K, but Sinclair ZX80, Sinclair ZX81
Hardware Hints Techniques for preventing overheating, memory loss. Sinclair ZX81
Hardware News: New peripherals Memotech Corporation announces the Memotech Keyboard for Timex/Sinclair 1000 and ZX-81 microcomputers. The direct-connect, typewriter-style keyboard has Sinclair legends on the keypad and comes with an interface device. The interface is buffered and is housed in a Memopak case, which plugs into the back of the Sinclair. Sinclair ZX81, Timex/Sinclair 1000
Hardware Preview: RD8100 System RD8100 motherboards and modules are building blocks that plug onto your computer or together to create instant systems. Sinclair ZX81
Hardware Tips Robert Hartung to comment on letters from readers. Responses should be regarded as suggestions to help look for the answers. Sinclair ZX81
Hardware Tips Robert Hartung comments on some letters from readers. His responses should be regarded as suggestions to help look for the answers. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Hidden Cave - A Fighting Fantasy Game Implementation of a short dungeon crawl adventure that uses the Fighting Fantasy combat system. Sinclair ZX81
High-Res Blackjack for the ZX81/TS1000/TS1500 High resolution graphics version of Blackjack using Silicon Mountain’s SCRAM Hi*Res Extended Basic and non-volatile RAM board. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Hints & Tips For The ZX81 Hints & Tips for the ZX81 by Andrew Hewson is excellent for the average ZX81 user who has little, or no knowledge of Z80 Machine Code programming, but would like to learn. There are sections on saving space in programs, understanding the Display File, converting ZX80 programs for use on the ZX81, how to let Sinclair ZX81
Hot-Z HOT Z is a valuable tool for the machine language pro or novice. Sinclair ZX81
How COMPUTE! Readers Use Their Computers John Crum of Auburn, WA, started with a ZX-81. Peter Lobl, a tenth grader in Lindenhurst, NY, started with a ZX-80. Sinclair ZX81
How I Made My Fullsize Keyboard Describes how to connect a surplus keyboard to a ZX81. Sinclair ZX81, Timex/Sinclair 1000
How Many Blocks Like most new computer owners, I was testing my new equipment with some games. My fun was interrupted, though, when I realized that I was being watched. As I turned, I was confronted by my five year-old daughter, Scooter. Wearing a sad face and eyes that reminded me of a beagle puppy, she muttered, “How Sinclair ZX80, Sinclair ZX81
IBM-AT Keyboard Interface for the ZX-81 Sinclair ZX81
IC Inventory This program, written for the CD4000 series of ICs and using the 4K ZX80 ROM and at least 2K RAM, can be adapted for any series of things following consecutive numbers. Sinclair ZX80, Sinclair ZX81
Improved Super Monzxer Game Improvements to Super Monzxer, which originally appeared in the November 1981 issue of Syntax. Sinclair ZX81
Improving Your ZX-81 Circuit modification to improve reliability of SAVEs. Sinclair ZX81
In and Out of Machine Language When you use machine language programs, you have no keys to press directly. So we need to tell the machine to RUN a machine language program, and to tell it to STOP. Sinclair ZX80, Sinclair ZX81
In and Out of SYNC Review of the Video Technology VZ200 computer and comparison to Sinclair BASIC. Sinclair ZX81
In Sync With Sinclair User pleased with his ZX81. Sinclair ZX81
Input/Output Letters from Bob Swoger, Les Cottrell, Jack Boatwright, Peter Liebert-Adelt, David Solly, Jay Shepard, Louis Florit, Frank Davis, Rita Jean Willis, John Pegram, Jerry Anson. Sinclair ZX81
Inside the T/S1000, ZX81 Description of the hardware that makes up these computers. Sinclair ZX81, Timex/Sinclair 1000
Installing a UHF Modulator Convert the ZX81 to UHF as a way of combatting interference. Sinclair ZX81
Instrument Automation using the Sinclair ZX-81 Sinclair ZX81
Interest This program computes interest over a certain period of time, at a selected interest rate. Sinclair ZX81, Timex/Sinclair 1000
Interfacing the ZX81 The ZX81 (or Timex Sinclair 1000) computer can be turned into a very powerful machine. Article discusses interfacing a clock/calendar chip, temperature indicator, light controller and heater controller. Sinclair ZX81, Timex/Sinclair 1000
Interfacing the ZX81, Part 2 The ZX81 (or Timex Sinclair 1000) computer can be turned into a very powerful machine. Article discusses interfacing a clock/calendar chip, temperature indicator, light controller and heater controller. Sinclair ZX81, Timex/Sinclair 1000
Interfacing the ZX81, Part 3 The ZX81 (or Timex Sinclair 1000) computer can be turned into a very powerful machine. Article discusses interfacing a clock/calendar chip, temperature indicator, light controller and heater controller. Sinclair ZX81, Timex/Sinclair 1000
Interfacing the ZX81, Part 4 The ZX81 (or Timex Sinclair 1000) computer can be turned into a very powerful machine. Article discusses interfacing National Semiconductor’s Digitalker chip. Sinclair ZX81, Timex/Sinclair 1000
Interfacing Tips and Troubles: Memory Mapped I/O on the Sinclair ZX81 Memory-mapped IO on a Timex/Sinclair computer. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
INTERP - The Kernel of Interactive Nuts In this article we present an easily extended, interactive interpreter, providing a stack oriented, dictionary based programming environment similar to FORTH. The interpreter is, thus, the basis for the more friendly, more interactive use of your computer. The ease with which INTERP can be coded is a dramatic demonstration of the power of the ZX81 Sinclair ZX81
Just For Fun Bombsmash; Space Pirate Attack; Space Age Graphics; Driver Sinclair ZX81
Just For fun Mousetrap; Unvader; Draw and Store; Number Nine; Eliminator Sinclair ZX81
Just for Fun Short programs from readers: Sinclair ZX81, Timex/Sinclair 1000, Downloadable
Just for Fun Renumbering by a USR Routine; Sweeper; Ed, the Head. Sinclair ZX80, Sinclair ZX81
Just for Fun Graphics Loop I; Graphics Loop II; Draw It. Sinclair ZX81
Just for Fun Zap; Blaster; Catch 25, or Playing Left Field; Bombs Away!; Grand Prix. Sinclair ZX81
Kaleidoscope Many “Kaleidoscope” programs have appeared over the years. These simple, but fascinating graphics displays have been adapted to virtually every computer ever built. The ZX81/TS family is no exception. Unfortunately, since the Z80 CPU in these machines is {effectively} clocked at only -5 mHZ in SLOW mode, the result is rather slow and BO-RING. Sinclair ZX81, Timex/Sinclair 1000
Kaleidoscope I resorted to machine code in an effort to write a fast program to display a kaleidoscope pattern on the ZX/TS screen. The resulting images may be viewed on the screen and printed out at will. Sinclair ZX81, Timex/Sinclair 1000
Keyboard Alternatives Alternatives to the Sinclair keyboard: overlays, beepers, full keyboards. Plans for wiring your own keyboard and list of keyboard alternative vendors provided. Sinclair ZX81, Timex/Sinclair 1000
Keyboard/System Conversion: The First 40/1 Keys The fundamental conversion described here can be made with almost any KB switch array. 40 keys, new or used, so long as the switches are normally open and are closed with a key stroke. Sinclair ZX80, Sinclair ZX81
Kids' Page Programs written by kids for kids. Sinclair ZX81, Timex/Sinclair 1000
Kitchen Sync To Build or not to Build? A Review of the Sinclair ZX81 Kit Sinclair ZX81
Kitchen Sync The first thing we did when we finished building our ZX81 kits was to play with them— poking through the manual, pressing new keys to see what they did, writing little test programs to see what could be done. It did not take us long to decide that the ZX81 had some features that made Sinclair ZX80, Sinclair ZX81
Kitchen Sync Two to the What? Recently, a cousin from Lincoinwood, Illinois, came out to visit. Along with him, he brought a couple of “extra credit” problems given him by his eighth grade science teacher. One of the problems was to calculate 2 to the 420th power. Sinclair ZX80, Sinclair ZX81
Kitchen Sync The Nanos Systems reference card is clear, concise, and, for its shortcomings, is the best handy reference for the ZX80/ZX81 I have seen. Sinclair ZX80, Sinclair ZX81
Kitchen Sync Writing a program to calculate mortgage payments. Sinclair ZX81, Timex/Sinclair 1000
Knight's Tour How to write a program to implement the Knight’s Tour chess puzzle. Sinclair ZX81, Timex/Sinclair 1000
Knowing Your Strengths As an Industrial Designer, I am often required to specify the minimum practical amounts of material and the most effective configurations that will safely support a given load before spending thousands of dollars in tooling to produce parts for testing. The program I developed for this task has proved extremely rewarding. Now I can try Sinclair ZX81
Lab Inputs for Common Micros. The game paddle inputs of Apple microcomputers provide a simple way to get laboratory measurements into the computer. Discusses these game paddles and the necessary interface software. Includes schematics for Apple built-in paddle electronics, TRS-80 game paddle I/O, Commodore circuit for user port, and bus interface for Sinclair/Timex, Commodore, and TI99/4A. (JN) Sinclair ZX81, Timex/Sinclair 1000
Large Letters for the 8K, 2K Machine One tool that has been useful to me is a Basic subroutine to create 4×4 characters for the 8K ROM. The routine works well enough and enhances the display. However, it is slow. If used repeatedly, the delay can be irksome. The obvious solution is to write a machine language subroutine to do the work. Sinclair ZX81, Timex/Sinclair 1000
Learning the Timex/Sinclair 1000/ZX81 Keyboard Sinclair ZX81, Timex/Sinclair 1000
Least Squares Data Analysis with the ZX80/81 One of the most common tasks of a computer is to perform statistical analysis and data manipulative type computations. Many of the computations involved are very tedious to perform by hand since they sometimes require a large number of reiterative calculations. Statistical analysis problems that take hours for a human (equipped only with pencil and Sinclair ZX80, Sinclair ZX81
Letter in Reply to Left Handed Ways of Working a Printer Writer’s method of connecting two computers to several printers. Sinclair QL, Sinclair ZX81, Timex/Sinclair 1000
Letters On UK imports; overworked ZX81; reader service cards; support from South Carolina; question about RAM pack compatibility; on the 2040; pricing RAM packs; Cosmos revisited. Sinclair ZX81
Letters Uses of 64K RAM; 2068; Bulletin Boards; ZTX-650 Transistor; Correction to ‘Say What’ Sinclair ZX81, Timex/Sinclair 2068
Letters REM on the 4K ROM; Mini-Billboard for 8K ROM; “Bar Charts” and Rubber Cement; Splitting Strings; Short Video Cable; The 5-6 Seconds of Silence. Sinclair ZX80, Sinclair ZX81
Letters 8K ROM Double Images; Taxman; An Inventory System; Hampson’s Plane; Flag Use Tip; ZX80/81 World; The Great Circle Route. Sinclair ZX80, Sinclair ZX81
Letters Help Wanted, Program Problems, ZX80 Slow Mode, The Hidden Chessmen Sinclair ZX81
Letters LSCROLL, Flag Use, Key and Token Expressions, Hams and the ZX81, ZX80 ROMs, Hardware Suggestion, Inventory Sinclair ZX81
Letters RUNning with Reduced RAM, Brick Busters, Help, Upgrading Problem, Inverse Matrix. Sinclair ZX81, Timex/Sinclair 1000
Letters Comet Crusher; DEF; Draw It; Strong KBD Signals; List Learning; Pantry Inventory; Lunar Lander. Sinclair ZX81
Letters: Interfacing the ZX81 Interfacing using a variety of relays. Sinclair ZX81, Timex/Sinclair 1000
Letters: Say What Suggestion for improving code in “Say What” (Sync 3:6). Sinclair ZX81
Letters: The Sinclair ZX81 Writer assembled ZX81 from a kit and it did not work; claims it was a model for France. Nigel Searle assured writer it was meant for US and offered to repair it free of charge. Sinclair ZX81, Timex/Sinclair 1000
Letters: The ZTX-650 Transistor Replacements for the transistor. Sinclair ZX81
Letters: Too good to be true? Writer questions whether the ZX81 is real and too good to be true. Sinclair ZX81
Letters: ZX81 Owners Alive and Well Thanks for publishing supporting articles. Sinclair ZX81, Timex/Sinclair 1000
Letters: ZX81's OK! Fan defends the ZX81. Sinclair ZX81, Timex/Sinclair 1000
Line Print Utility Reading computer-style text, where the words get chopped off at the end of the line, is easy enough once you get the hang of it. However, if the printout of a program is intended for use by people not used to this style, it is friendlier to PRINT out the text in a more legible Sinclair ZX81, Timex/Sinclair 1000
Line Renumbering Two approaches to renumbering program lines, one in Basic, the other in machine code. Sinclair ZX81
Linear Regression Computes the linear relationship between two sets of variables, expressed as the linear regression equation, and calculates the coefficient of determination, an indicator of the strength of the relationship. Given a set of two variables labelled X and Y, the program will yield an equation describing Y as a function of X. Sinclair ZX80, Sinclair ZX81
Link to the real world Review of Down East Computing’s VOTEM, an all-purpose voltage and temperature measuring system designed to interface with the TS1000, ZX81 computer or any Z80 based system. Sinclair ZX81, Timex/Sinclair 1000
List Learning with the Sinclair The Sinclair computers can be effective learning aids if the student or teacher has the software to set up learning situations. A program to assist in the learning process should meet several criteria. First, it should be self-explanatory. Second, it should have different modes of operation. Third, it should be practical as a learning tool. Sinclair ZX81
Loading Hexadecimal Listings This program converts the hex and stores it into a space explicitly for it. Sinclair ZX81
Loading Problems with ZX81 Kits If you have loading problems with a kit ZX81, see if you cracked C10 during assembly. Some machines LOAD fine with 1 (or 2)K internal memory, but not with 16K. Sinclair ZX81
Loan Amortization Revisited Sinclair ZX81
Loan Amortization Schedule Program gives you monthly payments and loan amortization information. Sinclair ZX81
Logic Chip Failure Symptoms Reader deduced that his ZX81 logic chip (ICl) had failed from the keyboard line and diode matrix. Sinclair ZX81
Looping the Loop How can you do long, complicated jobs using machines code— without having to write long, complicated programs in machine code? The answer, in a word: loops. Sinclair ZX81
LSCROLL - For Spectacular Screen Displays How would you like to be able to create a “Times Square” display which moves from right to left without upsetting other items on your ZX81 (or 8K ROM ZX80) screen? Would you like to display graphs or functions such as a sine wave on your screen when they need more than 32 columns of Sinclair ZX80, Sinclair ZX81
Lunar Lander You are the Command Pilot of the Lunar Lander SYNC. You are now in the final stages of your descent and you must make your landing before your fuel runs out. You select the thrust settings from your keyboard control system by pressing a key from 1 to 10. The computer does not wait for Sinclair ZX80, Sinclair ZX81
Machine Code -- CP Branching Tests CPs are 1-3 byte codes that compare two numbers. More exactly, they subtract the number you are looking for from what has been loaded into the accumulator. Sinclair ZX80, Sinclair ZX81
Machine Code Print Routine Machine language (ML) permits you to print characters anywhere on the screen. Harness the ZX80’s own print routine with RST 0010. Sinclair ZX80, Sinclair ZX81
Machine Code Programming -- Understanding the Stack Often when writing machine code (MC) programs, it’s useful to keep the MC above RAMTOP. But few people understand how to move RAMTOP and the Z80’s stack pointer from within MC. Sinclair ZX80, Sinclair ZX81
Machine Code Screen Fill Simple 16-byte machine code program fills the screen with any character. Sinclair ZX81
Machine Language Programming - Logical Functions Differences between 4K and 8K ROMs can be overcome with machine language. Sinclair ZX80, Sinclair ZX81
Machine Language Programming Made Simple Review of Machine Language Programming Made Simple for your Sinclair ZX80 and ZX81. Sinclair ZX80, Sinclair ZX81
Machine Language Programming Made Simple for Your Sinclair ZX80 and ZX81 Sinclair ZX80, Sinclair ZX81
Machine language simplified Review of Machine Language Made Simple For Your Sinclair ZX80 and ZX81. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Machine Language Storage in REM When a series of consecutive REM statements is to be used to provide storage for machine language the leading four bytes of the second and subsequent REMs cannot simply be overwritten. Your machine language program would almost certainly crash. The solution is relatively simple. Change the byte count of the first REM statement to include Sinclair ZX81
Macro Photo This program will allow the photographer to input the data which the ZX81 will use to figure the adjusted exposure time (for bellows length and reciprocity), the proper subject to lens distance, and the proper film to lens distance for a given image magnification. Sinclair ZX81
Making Backups for Machine Language Tapes There are two methods which can be used to make a backup: copying to a second tape or use the PEEK and POKE facilities of the ZX81. Sinclair ZX81
Making Music with the ZON X-81 Programming the ZON, Bi-Pak’s sound generator, to play a simple tune is no simple task. On the other hand, it is far from impossible, and this article should be of help to aspiring computer musicians. Channel Tuning Although many ZON registers are involved in programming a melody, the most confusing to deal with are the Sinclair ZX81, Timex/Sinclair 1000
Managing with the ZX81 The program below, written for a ZX81 with 16K RAM, is designed to answer management questions. It is, in fact, a suite of five programs linked together, with an initial menu to enable the user to choose from among them. It is based on a series of rapid statistical tests devised by Eric Duckworth, a Sinclair ZX81, Timex/Sinclair 1000
Maps and the ZX80/81 In this article, we will examine some ways of putting maps into your ZX80 or ZX81. We will also see how the Sinclair computers can generate complex maps by themselves. Sinclair ZX80, Sinclair ZX81
Mars Review of the adventure game from Aardvark. Sinclair ZX81, Timex/Sinclair 1000
Mass Storage for the TS-1000 Has Arrived! Overview of load utilities and mass storage systems including ZXLR8 Fasload, Winky Board, A & J Microdrive, and Aerco and Larken disk systems. Sinclair ZX81, Timex/Sinclair 1000
Mastering Machine code on Your ZX81 Review of the book by Toni Baker. Sinclair ZX81, Timex/Sinclair 1000
Mastering Machine Code on Your ZX81 Though written for the ZX81, Mastering Machine Code on Your ZX81 applies equally well to the Timex Sinclair 1000. Each chapter also includes addressing and programming procedures for the ZX80. The light conversational style is both entertaining and understandable. Sinclair ZX81, Timex/Sinclair 1000
Mastering Machine Code on your ZX81 Review of the book. Sinclair ZX81, Timex/Sinclair 1000
Math Support from Your ZX81 Four routines to help with math or algebra. Sinclair ZX81, Timex/Sinclair 1000
Math Tutor Program for Youngster Program to quiz children 7-10 on addition and subtraction at different levels. Sinclair ZX81, Timex/Sinclair 1000
Mazogs In Mazogs you are an adventurer searching for a treasure in a HUGE maze. You must find the treasure and return to the entrance of the maze within a certain number of moves. Scattered throughout the maze are creatures called Mazogs whose job is to stop and kill you. You can kill them if you Sinclair ZX81
Meditations on a Hypotrochoid The plotting capacity of the ZX80(81) enables even the least artistically talented to create some pretty dazzling displays. The much denigrated sine and cosine functions conceal mathematical mysteries that are invisible to mere number crunchers. Sinclair ZX80, Sinclair ZX81
Memory Decoding Above 16K Sinclair made the ZX81 RAM easy to decode up to 16K, but you may want to add memory beyond this point. To add more than 16K memory to your ZX80/81, you must do more than just: /A13 AND /A14 AND /A15 = /ROM CS. You’ll also need to account for the behavior of the display Sinclair ZX80, Sinclair ZX81
Memory Scrunching on the TS1000 and ZX81 One of the most serious problems that TS1000 users are faced with (and ZX81 users even more so) is the lack of memory (RAM). Most commercial programs require a 16K RAM pack, and many printed in newsletters and magazines require over 2K (or 1K for ZX81 people). Although the package or listing calls for 16K, Sinclair ZX81, Timex/Sinclair 1000
Memotech 64K Memopak The Memopak is undoubtedly the ultimate memory expansion for the Sinclair. Try DIM A(9500)! Sinclair ZX80, Sinclair ZX81
Merging With Randomness Seeding the RND function for greater randomness. Sinclair ZX81
Meteors How to use the display file; demonstrated in a video game. Sinclair ZX81, Timex/Sinclair 1000
MicroSync Services Brief article about “Sinclair’s Exclusive Authorized Service Center.” Sinclair ZX81
Modifications to SHREB-BP: A ZX81 Hi-Rex Graphics Utility Sinclair ZX81, Timex/Sinclair 1000
More BIT/S This program is a game I call ‘SECRET NUMBER.’ The computer holds a secret number whose value is anywhere between 0 and 50. You have to guess that number by using messages as cross references. As you enter a guess (input a number) the computer gives you a clue as to the general area of Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
More ZX81/TS1000 Hi-Res Pictures Sinclair ZX81, Timex/Sinclair 1000
MoTSart: Super Music for the ZX81/TS1000/TS1500 Machine code program to play music over the MIC output or on an AM radio Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Moving Billboard This program continuously scrolls up to 23 (and more) lines of characters. Do not print more than 32 characters in any PRINT instruction, such as line 150, or the scrolling will fail. Sinclair ZX81, Timex/Sinclair 1000
Moving RAMTOP in ZX-81/TS-1000 Sinclair ZX81, Timex/Sinclair 1000
Multisave Wouldn’t it be nice 1) to key in the number of saves required and leave the ZX81 to complete that number of identical copies? 2) not have to check what variables have been assigned before incorporating this feature in a program? 3) to retain the normal, single-save mode? If this appeals to you, try the Sinclair ZX81
My kind of town Tim Hartnell reports back from the Consumer Electronics Show. After some 18 months with the Timex version of the ZX81, Timex have managed to sell 600,000 of the machines in America.  The Timex stand was enormous, about the area of a four-room flat, and it was dominated by giant pictures of the T/S 2000 and Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
My Start with the ZX81 How Tim Swenson came to own a Sinclair ZX81 and, for a short while, was a software publisher. Sinclair ZX81
Need fast ZX80/ZX81 service? Service firm repaired partially-assembled ZX81. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
New 8K ROM Potpourri Sinclair’s first 8K ROM had a few bugs; list of changes to the 8K ROM map. Sinclair ZX81
New 8K ROM Routine Addresses Here are the starting addresses for routines in the corrected 8K ROM. All addresses are hex. Sinclair ZX81
New Magazine for Timex Sinclair Users A consortium of North American companies has come to gether to publish the first monthly magazine aimed solely at the 700,000 users of the TS1000 and ZX81. In what is one of the largest magazine launches into the home computer market, Timex Sinclair User will have an initial print run of 100,000. Sinclair ZX81, Timex/Sinclair 1000
New Product Announcement (Syntax v3 n6) ZX FORTH, battery back-up units. Sinclair ZX81
New Products and Services (Syntax v5 n1) New books from Prentice-Hall, Hayden; SRS Speech Recognition System from G. Russell Electronics; DO-CALC; Software from Banta Software; RAMPAGER from Robotec. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
New Products and Services (Syntax v5 n10) Cryptic Gold; fifth generation computing; ZX-Calc accounting system; budget robotics; graphics tablet from Zebra; programmer’s market; monitor tuners; Oddball Software Magazine. Sinclair ZX81, Timex/Sinclair 2068
New Products Directory: Fantasy/Adventure Programs Product announcement for “Adventure A” and “Adventure B” from Softsync. Sinclair ZX81
New Products Directory: Personal computer ZX81 briefly described. Sinclair ZX81
New Products: 64k-byte memory for ZX81 Announcement of Memotech 64K RAM pack. Sinclair ZX81, Timex/Sinclair 1000
New Products: Cassette-based software VU-Calc and VU-File available for Sinclair ZX81. Sinclair ZX81
New Products: Portable Computer From Sinclair Sinclair Research Ltd., has introduced the ZX81 microcomputer. The Sinclair ZX81 is based upon an innovative four-chip design, and it measures just 6×6.5×1.5 inches and weighs 12 ounces. Sinclair ZX81
New Releases New software from Ron Ruegg; “Touring the TS2068 ROM Operating System” book from William J. Pedersen; Arnold Ramaker is developing an expansion box for ZX81, TS1000, TS1500, TS2068 and QL computers; Matthew Zenkar offers utility for QL owners who use DTP software; Sinclair Artificial Intelligence Network special intereste group forming. Sinclair QL, Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
New Sinclair - Cheaper, Better The lowest-price personal computer is getting less expensive and gaining features. In England, Clive Sinclair, originator of the Sinclair ZX80 computer, recently introduced a revised version of his system, the ZX81. Introduced at a price about 30% lower than the original, the ZX81 adds features and corrects several of the faults of the ZX80. Sinclair ZX80, Sinclair ZX81
New Sinclair Computer Spectrum announcement. Sinclair has also come to an agreement recently with Timex to distribute the computers in North America; the two companies have been in close alliance for some time as the ZX81 and Spectrum are both manufactured in Timex’s Scottish plant. Sinclair ZX Spectrum, Sinclair ZX81
New ZX81 Hardware/Software Vendor Mindware Co. will introduce Barscan for ZX81s in the next few weeks. Barscan uses bar code technology to process collected data on attendance and job costs and can produce standardized printed reports. It provides 16K RAM and self-prompting programs for nontechnical users. Sinclair ZX81
Next from Sinclair: pocket-sized TV The flat screen that ICL will be incorporating into its new work station has been developed by Sinclair for a pocket-sized television it hopes to have in production by the middle of the year. The ZX81 is now sold strictly through mail order in this country at a cost of $150. Nigel Searle said that Sinclair ZX81
Nine Defenders Against the Aliens Review of Quicksilva’s Defender. Sinclair ZX80, Sinclair ZX81
Nonauthorized ZX81 Sales and Service National Electronics III of Concord, TN, has become a nonauthorized reseller of new assembled ZX81 systems. Sinclair ZX81
Northeast Computer Show in Boston draws 50,000 Many price-conscious buyers found their way to the Sinclair Research booth, where the company was selling its new ZX81 computer for $150, assembled, and under $100 unassembled. Sinclair representatives showed that the ZX81 could perform a variety of personal and financial functions, besides offering games. Sinclair ZX81
Not Entirely Clear Enter this line by hitting 1, CLEAR, cursor back, REM, NOT, /. Execute via RAND USR 16514. Sinclair ZX81, Timex/Sinclair 1000
Nuclear Decay Simulation A popular lab exercise uses special dice to simulate radioactive decay. Marked die faces show the decay probability. After shaking and throwing the dice, replace those with marked sides showing with spheres (stable atoms) or dice with different decay probability (radioactive daughters). Use over 200 atoms for a smooth graph. This program throws, examines and Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Numbers Held Inexactly on the ZX81 First in a series of articles on numerical errors in the 8K ROM. Sinclair ZX81
Numbers Held Inexactly on the ZX81 The largest is really this 39-digit number: 170141183420855150474555134919112130560. Sinclair ZX81, Timex/Sinclair 1000
Numbers Held Inexactly on the ZX81, Part 4 The ZX81 doesn’t hold simple decimals like .5 & .25 exactly. Sinclair ZX81, Timex/Sinclair 1000
Of Interest Sinclair has announced new ZX81 software, on cassette and developed by ICL, a large British computer company, and PSION, a Britsh software company. Sinclair ZX81
Oops! Another Mistake The ZX81 and Z88 were featured in Playboy magazine. Cambridge Z88, Sinclair ZX81
Op-Amp Design Short program to assist in designing 741-based opamps. Sinclair ZX81, Timex/Sinclair 1000
Perceptions In this issue I will discuss the ZX80/81’s display system. The ZX80/81 video display is created almost entirely by software. All sync (vertical and horizontal) is generated by 10 instructions in the display routine. Sinclair ZX80, Sinclair ZX81
Perceptions The ZX81 Parser and User-Defined Commands; More on the 16K RAM Pack Schematic; Addenda to “The ZX80/81 Video Display System.” Sinclair ZX80, Sinclair ZX81
Perceptions The ZX81 Parser (Part 2). In the last issue I began a discussion of the ZX81’s parser which is a complex and tricky combination of software techniques. In this article, I will continue the discussion by detailing the main parser routines. Sinclair ZX81
Perceptions This article is the third in a series discussing the ZX81 Parser. Since the first two articles may have been a bit too abstract for some readers, I hope this discussion will pull the previous articles together. Sinclair ZX81
Perceptions In this issue Perceptions will take up I/O (Input/Output) ports. The fundamental issues are discussed, and a sample method for their application to the TS1000/ZX81 is described. Sinclair ZX81
Perceptions: Syncsums Short program to provide checksums to users as they type in programs, to ensure they’ve been entered correctly. Sinclair ZX81
PET ASCII Output Program for the Timex/Sinclair ZX81 This article describes a project which may be useful for anyone desiring to use software for the ZX81, TS1000 or TS1500 on a different computer. The program version presented here is designed to convert Sinclair BASIC programs into ASCII text which can be sent from the Sinclair computer to the serial port of a Commodore Sinclair ZX81, Timex/Sinclair 1000
Phone Number Word Generator What does your phone number spell out if changed to letters? A friend’s phone number, 438-5678, spells GET LOST. A bank’s auto loan department answers NEXT CAR. Sinclair ZX80, Sinclair ZX81
Pi This program can calculate PI to over 8000 decimal places— but don’t hold your breath. It takes over 12 hours for 512 digits! The algorithm uses base 100 arithmetic, storing each digit in one byte of a character string (codes 0-99). It is based on the Taylor series for the arctangent. Sinclair ZX81, Timex/Sinclair 1000
Pin Connections for Spectum, TS 2068 and ZX81 Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Plane Frame Plane Frame is a mechanical and structural engineering program. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Player ZX81: A Tune-Playing Program For The Sinclair/Timex Review of Player ZX81 from Wm. Maples. Sinclair ZX81, Timex/Sinclair 1000
Plotting with Z88dk Describes how to add ZX BASIC PLOT/UNPLOT commands to the Z88dk C compiler. Sinclair ZX81
Port Projects: Get the LED-OUT In any number of monitoring and/or control uses for your ZX/TS, you may find that using a TV set to check on your system is inconvenient or impractical. This would be so, for example, in outdoor or dirty environments or when you simply wish to check the status of one or two system parameters without Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Printing on the 8K ROM One of the 8K ROM’s nicest features is its increased printing capability. Sinclair ZX81
Printing on the Bottom Line Here are two different ways to PRINT where you aren’t supposed to. Sinclair ZX81
Printing Strings Faster Use a full-length string of characters to print a bar graph instead of plotting each section. Sinclair ZX81
Problem-Solving Circuits If your power line voltage is 120V or higher and you use a 16K RAM, heat build-up in the ZX81 is a problem. Sinclair ZX81
Professional's Use TS Computers Australian Army uses 2068 as inexpensive simulator to teach soldiers the art of calling fire from an artillery battery or mortar platoon onto targets in the field. TS2068 used to run a retail business. Nursery uses TS2068 in many aspects of its business. Power transformer manufacturer uses 2068 for accounting, cost prediction and more. ZX81 Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Program Blitz Attempt to cure program loss due to wobble by repairing insulating pieces inside ram pack. Sinclair ZX81
Program Improvements Improvements to READ-DATA-RESTORE, Flower Plot, Income Tax program. Sinclair ZX81
Program Improvements Improvement to program in Numbers Held Inexactly, Mar and Apr 1982. Sinclair ZX81
Program Improvements Improvements to Big Characters, Line Renumbering and Powers of Negative Numbers. Sinclair ZX81
Program Improvements Corrections to 8K Digital Clock, Hexadecimal Math and 4K Blackjack. Sinclair ZX80, Sinclair ZX81
Program: An Animal Sinclair ZX81, Timex/Sinclair 1000
Program: Orbit around a planet Sinclair ZX81, Timex/Sinclair 1000
Program: Screen Patterns Sinclair ZX81, Timex/Sinclair 1000
Programming Concepts An exercise in learning about the actual aspects, functions and limitations of the Sinclair ZX81 microcomputer and it’s version of the BASIC language. Sinclair ZX81, Timex/Sinclair 1000
Programming the LOAD Command Do you have some machine code programs stored on tape that require POKEing RAMTOP before LOADing the program from cassette? Or are you writing your Basic programs around a favorite machine code POKEing routine? If so, knowing how to program the LOAD command can be a real convenience. Sinclair ZX81
Public Domain Libraries Sinclair QL, Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2068
Publisher's Remarks: Computer Games Wear Thin: When Will The Industry Grow Up? One of the more interesting cultural micro events in recent times was the visit of Clive Sinclair to Boston, where he did a show and tell of his ZX-81 system. Sinclair ZX81
Publisher's Remarks: Stay-at-Home Micros Clive Sinclair has been doing a first-rate job of getting his ZX-81 computers into the hands of people interested in learning about small computers. He’s been selling mostly via mail order so far. Starting in July, Timex will take over, selling the small computer through their chain of dealers. Sinclair ZX81, Timex/Sinclair 1000
Putting Forth on ZX80/81s Although BASIC is the most common language for programming microcomputers, it is not the only one. Your ZX80 or 81 can learn FORTH, another high level language. Sinclair ZX80, Sinclair ZX81
Q&A Problems with quality of 2068 display; TS1500 high res video; Aerco/Royal printer compatibility; curing interference on 2068 saves; more on spikes; print message notes; Canada customs. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
QSAVE The QSAVE package consists of: 1) a hardware unit, 2) a software program, and 3) an instruction booklet. It performs tape SAVE, LOAD, and verify at 4000 BAUD. Sinclair ZX81
Quest for the Holy Grail In this game you have thing you can pick up like guns, machetes, fishing nets, gold coins and other things. Since you are in the jungle and you can be killed by a savage ape, I suggest you use your gun, but you can use your own judgement. Sinclair ZX81, Timex/Sinclair 1000
Quick Tape Loading and Saving by Mindware QUICKLOAD software loads/saves 6x faster than current ZX/TS software and verifies whether the program loaded properly. Sinclair ZX81
RAM Decoding for ZX81 Last March we published Al Salt’s plans for adding external RAM to ZX80s. To adapt his Build Additional RAM (SYNTAX 02/03/02) with ZX81s, you can take ne of three approaches. The second two of these plans do not require you to modify the insides of your ZX81. Sinclair ZX81
RAND and Autorun RAND will not work properly on ZX/TS machines if the program RUNS automatically when LOADed. Sinclair ZX81, Timex/Sinclair 1000
Random Functions in 4K, 8K Compare RND (4K, 8K), RAND (8K), and RANDOMISE (4K) . Sinclair ZX80, Sinclair ZX81
Random Pixel Plot Two line program to randomly plots points. Sinclair ZX81
Random Walks A program “Random Walks” for the ZX81 duplicates the Hexstat. It is an eye-catching, pretty display and very effective as an instructional device. Over a period of 15 minutes or so a series of “balls” falls down through a cascade or sieve to form 9 columns whose heights are proportional to the respective probabilities of Sinclair ZX81
Reference Card for the ZX80, ZX81 and Timex Sinclair 1000 Copy of the Nanos reference card. Sinclair ZX80, Sinclair ZX81
Reference Card for the ZX80, ZX81 and Timex Sinclair 1000 Review of the card from Nanos Systems. Sinclair ZX81, Timex/Sinclair 1000
Release of ZX81Tape Announcement of program to convert programs on cassette to MSDOS files. Sinclair ZX81
REM Builder for TS1000 Seeing Mather White’s REM-expansion routine in T-S H reminded me of a REMBUILDER routine I use with my ZX81. It allows either building a REM to any desired number of characters or adding just one byte at a time. Sinclair ZX81, Timex/Sinclair 1000
Renumber Utility programs for renumbering the lines of BASIC programs facilitate merging with other programs, spreading out line numbers to make room for additional lines, and neatening up finished programs. Changing line numbers is easy, but a useful renumbering utility must also fix the destination line numbers in GOTOs and GOSUBs, a more difficult task. This Sinclair ZX81, Timex/Sinclair 1000
Renumbering Basic Statements This article presents two Basic renumbering programs in Sinclair Basic for the 8K ROM. The first program can be used with 1K or 16K RAM. It only renumbers the Basic statements. It does not do anything about the destination addresses for GOSUB and GOTO keywords that must be changed after a program is renumbered. The Sinclair ZX81
Repeat Key Option A repeat key option is relatively simple to build and install. Sinclair ZX80, Sinclair ZX81
Restart without Reload Use the WAIT signal to restart a ZX81/TS1000. Sinclair ZX81, Timex/Sinclair 1000
Resurrecting a Crashed Directory on the ZX81 Larken Technique for manually recovering a crashed directory. Sinclair ZX81
Reusable Loops You can shorten and clarify some of your programs by using one loop and several flag variables to perform related operations. For a sample, let’s take a utility that creates, modifies, moves, checks, and prints a ten-byte MC routine. Sinclair ZX81, Timex/Sinclair 1000
Reverse The object of this game, rewritten from one published by Creative Computing, is to get the numbers in ascending order from left to right. Sinclair ZX80, Sinclair ZX81
Review: Sinclair ZX81 The Sinclair ZX81 is reported to be the world’s most popular computer. It has been produced at a rate of 50,000 units per month since mid-1981. Sinclair ZX81, Timex/Sinclair 1000
Robotics on a Budget The Project A little over a year ago I decided to start building a robot. I had no idea that it would lead to a project fully controlled by a computer. However, as I started reading more about robots and the robotics law, I realized that a true robot had to be a self-contained entity Sinclair ZX81
ROMPAK ROM Card ROMPAK permits you to use many programs instantly—cartridges in the rough. An adaptor plugs onto your ZX/TS and provides a socket to contain the program ROM. A simple machine code routine in the ROM moves the program into RAM in under a second, and you’re ready to go. Sinclair ZX81, Timex/Sinclair 1000
Rounding off Routine The 8K ROM’s floating point decimal is great, but sometimes you don’t need 9 decimal places. Sinclair ZX81
Rounding Off with Conditional Tests We have all learned in plane geometry classes the Pythagorean theorem: a squared plus b squared equals c squared. Thus, if we know two sides of a right triangle, we can easily calculate the third. Or can we? Sinclair ZX81
RTTY Loop Bernard Ginsberg is working on interfacing his Sinclair ZX-81 (aka Timex 1000) to RTTY. Sinclair ZX81, Timex/Sinclair 1000
RUNning with Reduced RAM For most of us, the anticipation of being able to write extended programs when we first plugged in our new 16K RAM pack was soon somewhat tempered by the waiting out of the monotonous count at the end of every SAVE and LOAD. Also, functions such as CLS and NEW take much longer. Sinclair ZX81
Sad About Sinclair User experiences numerous issues with his ZX81. Sinclair ZX81
Safe Machine Code Routines More and more programs are appearing in SYNC, under the rubric of “machine language.” There was a time, not too long ago, when personal computer users were notoriously shy about venturing into these jungles. Nowadays, though, even someone who is not quite comfortable in Basic can manage to key in and run programs in Z80 Sinclair ZX80, Sinclair ZX81
Salary Scheduling Cost Computation This 8K/16K program computes salary schedules for two or three classes of teachers (or other workers). For a two column schedule, enter all zeros for the prompts about the third class (Mast+). At the end of the second column, it will ask if you want another. Enter NO and touch NL. The computer will give Sinclair ZX81, Timex/Sinclair 1000
Saving Your Fingers Edit existing lines and renumber to create multiple instances where the lines are very similar. Sinclair ZX81
Say What? Simple speech recognition hardware and program for ZX/TS computers (with at least 16K RAM). Sinclair ZX81, Timex/Sinclair 1000, Downloadable
Screen Background for Games A dark or solid background often gives a better effect for printing or plotting in games. With an 8K ROM and 16K RAM, an almost instant background is possible in BASIC. Sinclair ZX81
Sea War Sea War starts by scrolling from right to left a very impressive “title page” asking for the number of players (the limit is 2). A rather large ship then travels across the surface of the water and drops your submarine into the water; then the action starts. You are now in a submarine just below Sinclair ZX81
Search and Replace Routines The routines in are designed to search through a program and replace all occurrences of one character or keyword with another (keywords are represented with one byte, too). The routines can all be entered directly from the keyboard into a 1 REM line. Sinclair ZX81, Timex/Sinclair 1000
Servo Interface Connect a ZX81 to servos. Sinclair ZX81
Shifting Maze This program prints a maze on a 1K ZX81. Run in SLOW for best effect. Sinclair ZX81
Simple Reset Switch Instructions and schematic for adding a debounced reset switch. Sinclair ZX81, Timex/Sinclair 1000
Sinclair 8K ROM Software Sinclair now offers cassette programs for the ZX80 and ZX81 with 8K ROM. Sinclair ZX80, Sinclair ZX81
Sinclair Announces ZX81 Computer Sinclair Research unveiled a new computer at a press conference in England in mid-March. The ZX81 comes with the same 8K ROM that will be available for ZX80s and 1K RAM and sells for 30% less than the original ZX80. Sinclair ZX81, Timex/Sinclair 1000
Sinclair Clarifies Parts Position Sinclair only sells replacement parts to kit owners who received damaged parts with their kits. Sinclair ZX81
Sinclair doubles its ZX81 output The ZX81, which at $149.95 is the lowest priced personal computer on the market, was announced in the United States and Japan last month. Already interest from the announcement has generated 5000 orders that have actually been processed, according to Nigel Searle, director of the company’s office here. Sinclair Research sold over 100,000 of its Sinclair ZX81, Timex/Sinclair 1000
Sinclair Drops US ZX Prices as of 1 June Sinclair Research lowers the prices on their ZX products in the US 1 June 1982, according to Margaret Bruzelius of Sinclair. Sinclair ZX81
Sinclair Fall Computer Show Sinclair Research plans to hold computer shows to introduce its ZX81 this fall. Sinclair ZX81
Sinclair miss the bus Sinclair and Timex, were most conspicuous by their absence at the giant West Coast Computer Faire held in San Francisco at the end of March. The booth listed in the catalogue as being the Sinclair one was unmanned throughout the show, the most important computer show in the world. Some 40,000 people crammed into a Sinclair ZX81
Sinclair On the Net Some of the more interesting info pulled off the Internet in the prior few months, including a magazine dedicated to Spectrum emulators, new products for QL and a ZX81 magazine. Sinclair QL, Sinclair ZX81
Sinclair Product Updates Sinclair’s ZX81 computer reaches the US on Oct. 7, 1981. Sinclair ZX81
Sinclair Research message spreads Sinclair ZX81, Timex/Sinclair 1000
Sinclair Research's ZX80 has sold 30,000 units in the US, at $199. The ZX81, for $149, should be sold there soon. Mr C Sinclair claims it is the world’s most reliable computer, with only 1.9% machines returned, and most of these faults are due to customer mishandling. UK orders are being received at 1,000 a day. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Sinclair Spares and Repairs Sinclair ZX Spectrum, Sinclair ZX81
Sinclair ZX-81 Several letters in response to request for ZX-81 schematic. Letters include details about user’s experiences. Schematics of ZX80, ZX81 and 16K ram pack. List of Sinclair/Timex book; includes brief summary of each book. Also, discussion of emulator options available at the time. Sinclair ZX80, Sinclair ZX81
Sinclair ZX81 Review, reprinted from Personal Computer World. Sinclair ZX81, Timex/Sinclair 1000
Sinclair ZX81 - Toy or tool? Sinclair ZX81
Sinclair ZX81 'Devoted' to Owners Clive Sinclair, inventor of the first pocket calculator and first pocket TV, showed off his almost pocket computer, the ZX80, at CES. Sinclair has beefed up the ZX80, introducing a $39.95 8K BASIC chip and $99.95 16K RAM add-on module. The 8K BASIC has log, trig and other functions; graphics; and floating point arithmetic to Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Sinclair ZX81 FAQ Version 1.3, revised June 13, 1995. Sinclair ZX81
Sinclair ZX81 Personal Computer Sinclair ZX81, Timex/Sinclair 1000
Sinclair ZX81 ROM Disassembly Part A: 0000H-0F54H Ian Logan has disassembled and annotated the ZX81 Monitor, easing your access to the improved 8K ROM. Sinclair ZX81, Timex/Sinclair 1000
Sinclair ZX81 Schematic Sinclair ZX81
Sinclair ZX81/Timex Sinclair 1000 Statistics Review of Sinclair ZX81/Timex Sinclair 1000 Statistics: Twelve 16K Programs Including Multif actor Analysis of Variance by A. H. Wolach and M. A. McHale. Sinclair ZX81, Timex/Sinclair 1000
Sinclair's Latest Review of the ZX81. Sinclair ZX81
Sinclair's Printer Shown in US Clive Sinclair of Sinclair Research demonstrated his ZX81 printer at the the US introduction of the ZX81 computer in Boston on Oct. 7. Sinclair ZX81
Sinclairdom's Favorite Nerd Sinclair ZX81
Sinclairs Need Solid State TVs Sinclair ZX81
Sine Name Print any string in the form of a vertical sine wave. Sinclair ZX81
Software News: TimeWare TimeWare, a new line of software and books designed for the Timex/Sinclair 1000 series of computers, is available from Reston Computer Group. The TimeWare product line includes seven new software games, a six-volume series of self-teaching math software and eight books. Adventure games, arcade-type games and traditional games such as chess are included. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Software Received: XFORTH Sinclair ZX81
Software Review: British TS1000/ZX81 Software Reviews of Rocketman, Forty Niner and ZXtricator. Sinclair ZX81, Timex/Sinclair 1000
Software Review: ZX Galaxians Review of the Artic Computing program. Sinclair ZX80, Sinclair ZX81
Solutions of N x N Simultaneous Linear-Equations By Gauss Elimination Gauss Elimination is one of the oldest, most commonly employed, efficient, and straight forward methods of obtaining the solution of sets of simultaneous linear equations on a digital computer. This method is very easily understood and programmed. Sinclair ZX81, Timex/Sinclair 1000
Solving Implicit Functions on the ZX81 The computer can handle problems of this kind by making a series of successive approximations: try out any value of X, and see if it gives the Y you want; if it does not, then try another value of X. Sinclair ZX81, Timex/Sinclair 1000
Solving Simultaneous Equations This 8K/1K program uses Crout’s reduction to solve simultaneous equations. The number of variables you can use is limited only by your available memory; in 1K this program solves up to 4 equations in variables Sinclair ZX81, Timex/Sinclair 1000
Sort Routine This routine can sort 20 words of 20 characters in about 8 seconds. Sinclair ZX81
Space Taxi You are the pilot of a space taxi in the year 2081. You have just picked up a fare who must catch the next ship to Zeta Chi LXXXI. Naturally, there is a big tip if you make it in one piece. You control your taxi by the 6 and 7 keys to avoid the Sinclair ZX81
Spaces in REM Statements If you put your machine code in large REM statements, you need not laboriously type in spaces or digits. Sinclair ZX81
Speech Synthesizers Your ZX/TS computer can talk to you, with the help of a 'Speech Synthesizer' system. Speech or voice synthesis systems are combinations of hardware and software which, when tied in with your computer, can put electronically generated sounds and noises together into intelligible words and phrases. Sinclair ZX81, Timex/Sinclair 1000
Speed Up Your Programs Most Sinclair users are new to the programming game. Many will use lines like: 350 GO TO 710. In most cases this is fine, especially in a short program. But in a long program with many GO TO statements, the computer takes a long time for each TV display. Sinclair ZX81
Split and Save Would you like to freeze the upper part of your display screen? With “Split ‘n Save” you can! While the information in the lower portion is appearing and disappearing, any test or graphics in the upper portion remain on view. Sinclair ZX81, Timex/Sinclair 1000, Downloadable
Sprite Maker Machine code program to support fast moving graphics Sinclair ZX81, Timex/Sinclair 1000
Staff: Teacher and Tester "Staff" is a versatile music education program that reviews notes from the first ledger line below the staff to the first ledger line above. Sinclair ZX81, Timex/Sinclair 1000
Starblasters In “Starblasters” you must defend a sector of space from the invading alien spaceships. Your weapon is a powerful ion beam. But beware! The aliens can fire back. They can blow up your ship or even overrun your sector. Although you have five excellent ships in your fleet, you must be quick, skillful, and sometimes Sinclair ZX81, Timex/Sinclair 1000, Downloadable
Steady state enzyme kinetics: experimental design and data analysis by microcomputer One of the most time-consuming, yet essential, operations involved in the steady state kinetic study of enzymes is the design and optimization of experimental conditions. A computer program was developed for the Sinclair ZX-81 (or TS-1000, 1500) microcomputer which will optimize substrate concentration for preliminary and subsequently more refined kinetic analysis of one, two or Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
String Function Translation for 8K Equivalents of LEFT$, RIGHT$, MID$ and TL$. Sinclair ZX81
Stringing along with the ZX81 Using string statement to emulate READ/DATA by slicing the characters from the string which make up a data-set, converting the sliced substrings to a numerical value, if necessary, and then using these substrings as program variables. Sinclair ZX81, Timex/Sinclair 1000
Style and Speed in BASIC When you write a BASIC program, the order in which you carry out your tasks affects the speed of your program. Sinclair ZX81, Timex/Sinclair 2068
Super Monzxer This adventure game of survival challenges you with man-eating spiders, giant bats, pits and monzxers. You are in a cave with 5 levels of 20 rooms each. Sinclair ZX81
Supply Protector Battery backup power supply for ZX81. Sinclair ZX81
Surplus Keyboard Improvements for Extra Shifted Keys The TI 99-4A keyboards, still widely available, are an ideal unit for the ZX81/TS1000 computers. Recent and not so recent articles have shown how the shifted keys on the KB-0 line cam be connected using two diodes. This method can give you four useful and often used shifted keys: EDIT, DELETE, quotation marks, and FUNCTION. Sinclair ZX81, Timex/Sinclair 1000
Surplus Keyboards Plus Directions The $20 surplus keyboards from John J. Meshna Jr., Inc., mentioned in the Dec. 81 issue, now come with wiring instructions for ZxX80s. Sinclair ZX81
SYNC at the Library Books available about the TS1000/ZX81 and TS2000/Spectrum. Sinclair ZX Spectrum, Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 2000
Sync Notes ZX81 —The Family Increases; PERCEPTIONS; SYNCSUM; Spaces in PRINT Statements; MicroAce II????; SYNC Subscribers Pass the 6000 Mark; A P.S. from Alger Salt. MicroAce, Sinclair ZX81
Sync Notes SYNC program listings; 8K ROM problems; SYNC subscriptions; ZX Microfair; SYNC in Microcomputer Index; SYNC Notes: UK; Sinclair Launches the ZX Printer; Sinclair to Sell ZX81 Retail. Sinclair ZX80, Sinclair ZX81
Sync Notes ZX Microfair Report; ZX81 Launched in the U.S.; The World of Compukid; Second ZX Microfair to be Held Sinclair ZX81
Sync Notes The Second ZX Microfair Report Sinclair ZX80, Sinclair ZX81
Syntactic Sum Loader Machine code routine to help assure correct program entry. Sinclair ZX81
Syntactic Sum with Variables Modified version of Syntactic Sum to check variables in memory as well as program. Sinclair ZX81
Syntax Error Two errors in Machine Code Print Routine. Sinclair ZX80, Sinclair ZX81
Syntax Errors SABRE’s address is 1718, not 1719, Autrey (Nov.81). Lance Ward’s 8K Slalom program (Dec.81) contained 1 error. Sinclair ZX81
Syntax Errors Peter Ulrich, New York, sent corrections for Paul Ezra’s Brownian Motion program (Dec. 81). David Ornstein corrected his New 8K ROM Routine Addresses list (Jan. 82). Jon Passler sent some improvements for his 8K Bar Chart program (Jan. 82) to speed up program execution. Sinclair ZX81
Syntax Errors Jon Passler noticed an error in his 8K Roundoff routine (Oct. 81). Sinclair ZX81
System Expansion Hardware System Enclosures and Radio Frequency Interference; an add-on expansion bus. Sinclair ZX81, Timex/Sinclair 1000
T-S News Dan Ross resigns from Timex. Book announcements from Wayne Green Books, Softmark Associates. Software and hardware announcements from multiple vendors. Sinclair ZX81, Timex/Sinclair 1000
T/S 1000/ZX81 External Keyboard Buffer Sinclair ZX81, Timex/Sinclair 1000
T/S Help and Information Source of paper for the ZX printer; problem with ZX81 that could be bad SCL; non-working keys on a TS1000. Sinclair ZX81, Timex/Sinclair 1000
Tax Shelter Time Bomb Calculate the point at which a tax shelter returns taxable income. Sinclair ZX81, Timex/Sinclair 1000
Teach Kids to Count with the ZX81 With your ZX81 and some intelligent program design, your TV can provide sharp graphic images of concepts you want to teach. Sinclair ZX81, Timex/Sinclair 1000
Teaching with the ZX81 The Educational ZX80/1 Users 1 Group (EZUG) had a triple celebration in January. First, we were able to breathe a sigh of relief that we had survived a year of frenzied activity. Secondly, we welcomed the thousandth subscriber to our bimonthly newsletter. Thirdly, we launched our first educational ZX81 programs, fourteen of them in fact. Sinclair ZX81, Timex/Sinclair 1000
The "QS Sound Board" for the ZX80/81 Based on the extremely versatile AY-3-8910 sound generator chip, the QS Sound Board features complete software control of the frequency and amplitude of three independent output channels as well as an envelope shaper and noise channel. Mentions QS Motherboard, which allows connecting 16K RAM and sound board at the same time. Sinclair ZX80, Sinclair ZX81
The "QS Sound Board" for the ZX80/81 Based on the extremely versatile AY-3-8910 sound generator chip, the QS Sound Board features complete software control of the frequency and amplitude of three independent output channels as well as an envelope shaper and noise channel. Mentions QS Motherboard, which allows connecting 16K RAM and sound board at the same time. Sinclair ZX80, Sinclair ZX81
The 4th Personal Computer World Show Report on computer fair. Sinclair products mentioned include ZX82, ZX81 and printer. Sinclair ZX81
The Aerco Disk Drive System Review of the AERCO disk drive system for the TS 1000. Sinclair ZX81, Timex/Sinclair 1000
The Complete Sinclair ZX81 Basic Couse Review of book/tapes by the same title. Sinclair ZX81, Timex/Sinclair 1000
The Computer Tutor: READ, DATA & RESTORE Simulating READ/DATA/RESTORE on the ZX-81. Sinclair ZX81
The Editor's Forum Description of Tim Stoddard’s “souped-up” ZX81: 64K RAM, improved heatsink, digital aquisition module (A/D, D/A, realtime clock) as encountered at the 1987 Midwest TS Computer Fest. Sinclair ZX81
The Expandable ZX80 and ZX81 Author offers seven documented projects and several ideas for additional projects. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
The Exploding Bookshelf Books published about SincIair/MicroAce computers. MicroAce, Sinclair ZX80, Sinclair ZX81
The Fantastic Music Machine and Light Show The Fantastic Music Machine is a unique program that transforms your computer keyboard into a 3-octave musical instrument with reasonably good tonal quality with 16K it can handle up to 7000 notes. Sinclair ZX81, Timex/Sinclair 1000
The Flags of the 8K ROM Program The ZX81 manual states that the three system variables FLAGS, FLAGX and CDFLAG hold various flags to control the BASIC system. But a study of the 8K ROM program discloses 12 separate flags. Sinclair ZX81, Timex/Sinclair 1000
The Flags Register Part 3 of series on machine code programming. Sinclair ZX81, Timex/Sinclair 2068
The Game of Life Revisited - An Assembly Version The Game of Life, printed in SYNC 1:2 (pp. 28-30), was written in Basic. This Basic program may be replaced with an assembly subroutine which displays each succeeding generation within a fraction of the time needed by the Basic program. Each generation is constructed and then displayed by using another assembly subroutine for creating a Sinclair ZX80, Sinclair ZX81
The Great Circle Route “The Great Circle Route” shows something of its possibilities. After entering the program on your computer, enter the latitude and longitude of any two points in the world, and the computer will calculate and display the distance between them. This is the “great circle route.” Sinclair ZX81
The Great Connecticut Kit-Building Experiment New Haven teacher Chris Baldwin enrolled 28 kids in his 10-week ZX81 workshop. Sinclair ZX81
The History of QZX History of the ham radio focused computing magazine founded by Martin Irons. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 2068
The Ins & Outs of the Timex TS/1000 and ZX81 Review of the book by Don Thomasson. Sinclair ZX81, Timex/Sinclair 1000
The Linear Search Do you want to store and retrieve information with your computer? This program uses a machine language search routine that is so fast you can blitz through a full 13000 bytes of files to find the one you want in less than a second! Sinclair ZX81, Timex/Sinclair 1000
The Logical Operators Reprint of Sharon Zadetto Aker article from Sync about using logical operators to save time and memory. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
The Man Behind the ZX81 Sinclair ZX81, Timex/Sinclair 1000
The New Compilers Sinclair ZX81, Timex/Sinclair 1000
The PEEK Function and the POKE Command This article returns to Basic to discuss the PEEK function and the POKE command. Since the 8K ROM is now widely available, both the 4K ROM and the 8K ROM are included in the discussion and program illustrations. Sinclair ZX80, Sinclair ZX81
The Quicksilva Programmable Character Generator The Quicksilva Programmable Character Generator is a single circuit board which plugs into the QS Motherboard or the QS Edge Connector which plugs into the back of the ZX81. Once installed, it lets the user program 128 different characters rather than the previous 64 and their inverses. After the board has been programmed, it can Sinclair ZX80, Sinclair ZX81
The Sinclair Grade Book In preparing a grade book program for the Sinclair, it was first necessary to decide upon the form the recorded data should be returned in. One of the advantages of a good program is that it may be returned in any number of forms, at the operator’s discretion.In the following program, I have included provisions Sinclair ZX81, Timex/Sinclair 1000
The Sinclair ZX81 Review of the book by Randle Hurley. Sinclair ZX81, Timex/Sinclair 1000
The Sinclair ZX81 Programming for Real Applications This book is aptly billed as being for people who want to get down to business with their ZX81s. Sinclair ZX81, Timex/Sinclair 1000
The Sinclair ZX81: Small Review of a Small Computer Sinclair ZX81
The Stock Market Calculator The Stock Market Calculator helps the investor (or user) solve the complex equations inherent in Investment Analysis. Sinclair ZX81
The Thurnall System The TE devices are a sound investment: They are well built and at a reasonable price for Sinclair expansion. If you do not have any electronic experience or applications along those lines, you will probably be interested only in the parallel port and the joysticks. Sinclair ZX81, Timex/Sinclair 1000
The Unprintable Characters Sinclair ZX81, Timex/Sinclair 1000
The ZON X-81 Sound Generator The Bi-Pak ZON promises a "huge range of possible sounds." It certainly has great potential, but that potential is not so easily realized. Sinclair ZX81, Timex/Sinclair 1000
The ZX Data-Finder The ZX Data-Finder is one of quite a variety of data handling programs now available. Typical uses for such programs include: names & addresses; inventory catalogues; customer/client records; graphic charts; product descriptions; statistics; appointment calendar; personnel files; hobby collection/with cross referencing. ZX Data-Finder does these and more because the flexibility of the program lends itself Sinclair ZX81
The ZX Stock Exchange You have just inherited $10,000 from a wealthy uncle who made it big on the stock market. He also gave you the modem number of his broker, a computer. The ZX Stock Exchange carries stocks listed on the New York Stock Exchange as well as stocks not listed there. Sinclair ZX81, Timex/Sinclair 1000
The ZX-80 Versus the ZX-81 Incompatibilities between the ZX-80 8K ROM and the ZX-81. Sinclair ZX80, Sinclair ZX81
The ZX80 and ZX81 in the USA Background about Sinclair Research Ltd., its entry into the United States marketplace, and its first two computers. Sinclair ZX80, Sinclair ZX81
The ZX80/1 As Fortune Cookie In addition to reputed oracular powers, the I Ching has proven to be a source of fascination for mathematicians and computer scientists. This ancient Chinese system of divination comprises one of the earliest known examples of a binary counting scheme. Sinclair ZX80, Sinclair ZX81
The ZX81 Companion Bob Maunder’s new book is very different from The ZX80 Companion. It aims to appeal to every ZX81 owner, but more to “students” of computing whether at home or at school. Sinclair ZX81, Timex/Sinclair 1000
The ZX81 Companion The ZX81 Companion, like other ZX81 books, is totally applicable to the TS1000. It begins with a chapter on graphics techniques. First the screen field is explained. Then PLOT and UNPLOT are used to develop the basic components in graphics: drawing straight lines, using triangles, circles, parabolas, and ellipses, and moving a point around the Sinclair ZX81, Timex/Sinclair 1000
The ZX81: Upgraded Computing Power Sinclair ZX81, Timex/Sinclair 1000
Tidying Up Your Display Routines to print, display and sum series of values. Sinclair ZX81, Timex/Sinclair 1000
Tight Security Sinclair ZX81
Timex buys it up Sinclair Research have signed a deal with Timex in America to get the ZX81 sold through some 171,000 retail outlets in the States. Very shortly, lucky Americans will be able to buy ZX81s from the same shops which sell jewellery, perfume and Timex watches. Uncle Clive will get a royalty on all sales under the Sinclair ZX81
Timex modifies ZX-81 for U.S. TIMEX is learning from its close association with Sinclair Research and introducing its own low-cost microcomputer in the States. Selling at $99.95, the Timex Sinclair 1000 is a 2K RAM version of the ZX-81 and is the first computer to sell for less than 100 dollars. The ZX-81 costs slightly less than 150 dollars. Sinclair ZX81, Timex/Sinclair 1000
Timex Plans Computer to Retail at About $100 The Timex Computer Corporation, an affiliate of the company that introduced the world’s first inexpensive wristwatch, yesterday introduced the first personal computer to retail at around $100. Sinclair ZX81, Timex/Sinclair 1000
Timex Sinclair 1000 Timex, the watch company that has always built Sinclair computers, will market and distribute Sinclair-based products in North and Central America and the Carribean beginning this year. Sinclair ZX81, Timex/Sinclair 1000
Timex will market Sinclair computer At a press conference held in London last month, Sinclair president Clive Sinclair released details of an extensive marketing agreement with Timex Corporation. Sinclair has licensed Timex to use Sinclair technology to manufacture and market personal computers, peripherals and software throughout North America. Sinclair ZX81
Timex/Sinclair games offer excitement or ennui Here’s some more recreational software for you hard-working Timex/Sinclair 1000 (and ZX81) owners. Reviews of Mothership (Softsync), Gulper (HES), Bat-Cage (Timex). Sinclair ZX81, Timex/Sinclair 1000
Tips on ZX81/TS1000 Computer Repair Tips for resolving common problems. Sinclair ZX81, Timex/Sinclair 1000
Totally Safe Machine Code for the ZX81 and TS1000 Tips for writing safe machine code. Sinclair ZX81, Timex/Sinclair 1000
Translating Programs: On ... Go To Techniques for translating programs from other BASICs. Sinclair ZX81
Translations: Memotext in RAM Here is how to make a copy of the “Memotext” word-processor, which you can save to tape and reload later into RAM or NVM (non-volatile memory) in the 8-16K range. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Translations: Memotext to ZX Pro/File If you have a Memotext word-processor module and 64K RAM, you undoubtedly have already made use of its powerful “text” files mode. Memotext also supports “data” files, organized in six fields per file, up to 31 characters per field. Entering data files is just as easy and fast as text, thanks to the re-defined keyboard, Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Try These Short programs that demonstrate graphics and audio features of the TS1000/1500/ZX81 and TS2068. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
Try This Short program to plot Lissajous patterns. Sinclair ZX81
Try This Sinclair ZX81
Try This Get a small AM radio and tune it for best response. Then press RUN and NEWLINE. Note the sound as you press NEWLINE. The display may be ignored. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Try This This column will feature short programs to show off your computer, impress your family and friends, and tickle your imagination when SYNC arrives at your place. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Try This Type in the following program. Then RUN and NEWLINE. Type in any character or symbol when the quotation marks appear and hit NEWLINE again. Observe the results. Repeat until you get back to program. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Try This Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Try This Three short programs. Sinclair ZX81, Timex/Sinclair 1000
Try This Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Try This Sinclair ZX81, Timex/Sinclair 1000
Try This Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
Try This Short program. Sinclair ZX81
Turbo Switch for the ZX-81 Sinclair ZX81
Turbo Switch for the ZX81 Transcribed from the Winter 1993 issue of ZXir QLive Alive. Sinclair ZX81, Timex/Sinclair 1000
Turtle Graphics Have you ever wished for an easier way to create graphics displays on your Sinclair computer? You can always use a line drawing program and a table of coordinates, but setting up the table can be tedious. The LOGO language, developed by the artificial intelligence group at MIT, has a graphics system called Turtle Graphics Sinclair ZX81, Timex/Sinclair 1000
TV Sync Solution Dim lines and horizontal distortion moving up or down the screen are signs of the computer not syncing with horizontal sweep. Sinclair ZX81
Two Problem-Solving Circuits: Preregulator and Battery Backup Add a voltage regulator to your Sinclair power supply; build a batter backup unit. Sinclair ZX80, Sinclair ZX81
Two Switch Human Interface for the Communicative Impaired The program will usually display three rows of characters on the screen at any lime: the upper alphabet (UA) row, the lower alphabet (LA) row, and the message row. which will be empty at first. The program allows the user to select letters from the alphabet rows for display in the message row. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
UM-64 Memory Module Using bigger memories creates opportunities for greater losses in a crash. Byte-Back’s battery-back-up scheme cuts this risk. You’ll also get the possibility to have your operating system in RAM (all but the characters), compatibility with the TS1500, switch-selectable banks in the 8-16K area, an EPROM socket you can switch-select into 8-16K, and reasonable documentation from Sinclair ZX81, Timex/Sinclair 1000
Understanding Floating-point Arithmetic, Part 2 Describes the workings on the ‘third language’ of the 8K ROM – the CALCULATOR LANGUAGE – that is used to add, subtract, multiply, divide and generally manipulate floating-point numbers. Sinclair ZX81, Timex/Sinclair 1000
Understanding Floating-point Arithmetic, Part 3 In this article on floating-point arithmetic, we will consider the algorithms that are used in the 8K ROM program to perform the operations of subtraction, addition, multiplication, and division. Sinclair ZX81, Timex/Sinclair 1000
Understanding Floating-point Arithmetic: Part 1 The aim of this article is to give the reader some insight into the complex world of floating-point arithmetic. Since the 4K ROM provided only integer arithmetic, readers who possess only this ROM will be unable to try the programs. Nevertheless they will be able to follow the text. Sinclair ZX80, Sinclair ZX81
Understanding Your ZX81 ROM SYNC readers will recognize Dr. Logan as a major ZX80/81 expert whose writings are well worthwhile. Understanding Your ZX81 ROM is no exception. The book is written for a serious beginner who has a fairly good knowledge of Basic and wishes to take advantage of Z80 machine code execution speed. It supplements, but does not Sinclair ZX81, Timex/Sinclair 1000
Universal Printer Driver In Volume 1, I ran a series on getting the most out of your ZX/TS with full-size printer and Memotech Centronics interface. Since then, this CIF has become unavailable. Fortunately, several other printer interfaces (both parallel and serial) are available. These include Centronics Parallel IF’s by Aerco, Byte-Back, John Oliger, and Tasman, and serial IF’s Sinclair ZX81, Timex/Sinclair 1000
Update: Sinclair to be sold by Timex Sinclair Research has licensed exclusive North American marketing rights to Timex Corp. Sinclair ZX81, Timex/Sinclair 1000
Updating the Oldest Science Astronomers are using microcomputers in a variety of applications. “Andrew Hollis has done a particularly capable job on a low-cost Sinclair ZX81.” Sinclair ZX81
Upgrading to a "Real" Keyboard: E-Z Key Makes It Easy Schematic to add a keyboard that plugs into the expansion port. This is the same interface that is used in the E-Z Key 60. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500, Timex/Sinclair 2068
Upgrading VU-Calc 1000 VU-CALC for the ZX81/TS1000-1500 is a good program, but it has some limitations. Fortunately, modifications can easily be made which overcome these three limitations. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
User Report: Insight's 16K RAM Pack At first glance you might ask, “Is that all there is to it?” I opened the shipping box to find a small black plastic case that obviously plugs into the rear of a ZX80/81 or MicroAce computer. Sinclair ZX81, Timex/Sinclair 1000
Using HRG-ms Overview of a high-resolution toolkit for the ZX81 by Matthias Swatosch. Sinclair ZX81
Using the Byte-Back BB-1 and the ZX81 as a Control Device Describes using the ZX81 and Byte-Back device with a Skinner box. Sinclair ZX81, Timex/Sinclair 1000
Using the ZX81 as an Instrument Controller Review of an article about using the ZX81 in a research lab. Sinclair ZX81, Timex/Sinclair 1000
Vector Graphics Hardware and software to interface a ZX81 to an oscilloscope or other vector display and draw draphics. Sinclair ZX81
VuCalc Overview of Vu-Calc, a spreadsheet for the ZX81/TS1000. Sinclair ZX81
WARP 81: Making a 4K Program Run in 8K Details converting a specific program to work with 8K ROM Sinclairs. Sinclair ZX81, Timex/Sinclair 1000
Watch Where You Are Going In many games you need to know if something is already in the space where you are about to print another character. Whether you are firing a missile at a target, having PacMan gobble dots, or checking for a dead end in a maze, the method is the same: calculate the new position tor your Sinclair ZX81, Timex/Sinclair 1000
WH Smith Brings ZX-81s to the High Street Reprinted from Your Computer. Sinclair ZX81
What about the '81 The Spectrum does not replace the ZX81, as the 81 did the 80 – it’s an addition to the range and the ZX81 will continute in production. In fact, the production of the 81 is to be increased by a target of 150,000 a month by the end of the year. Sinclair ZX81
What's New? Speech Module for Sinclairs, Sin-Time Review Research In Speech Technology (R.I.S.T) Parrot module; announcement for Sin-Time Review, a bi-monthly about the Timex and Sinclair computers. Sinclair ZX81
Where to Find ZX-81/TS-1000/TS-1500 Supplies List of vendors who support the three computers as of 1986. Sinclair ZX81, Timex/Sinclair 1000, Timex/Sinclair 1500
Wherefore the DATA Statement Technique for simulating READ, DATA, RESTORE. Sinclair ZX81
Wind Chimes and the ZX/TS Computer Program to calculate the lengths of tubing for wind chimes. Sinclair ZX81, Timex/Sinclair 1000
Window A machine language monitor is a utility, provided by most computer systems, which aids in the development of machine language programs. Its basic functions are: a) to allow you to view the contents of each byte in the system’s memory, and b) to allow you to change these values. The program provided here will allow Sinclair ZX81
Window A machine language monitor is a utility, provided by most computer systems, which aids in the development of machine language programs. Its basic functions are: a) to allow you to view the contents of each byte in the system’s memory, and b) to allow you to change these values. The program provided here will allow Sinclair ZX81
Word Processing on ZX/TS Computers Comparison of wordprocessing and text editing programs for the Timex/Sinclair 1000. Sinclair ZX81, Timex/Sinclair 1000
X-tra BASIC This series will give you that little extra which is not directly available from the keyboard.This little extra which will allow you to adapt more easily programs from other BASIC languages. This little extra that will allow you to create better programs … FASTER running programs. Sinclair ZX81, Timex/Sinclair 1000
Your Timex Sinclair 1000 and ZX81 Review of the book by Douglas Hergert. Sinclair ZX81, Timex/Sinclair 1000
Your Timex/Sinclair Can Become a Terminal Build a 8251 USART interface to connect a Sinclair to a modem. Sinclair ZX81, Timex/Sinclair 1000
Zeta Software MCD Name Changer. Sinclair ZX81
ZX 80-81 Programs Four programs: trigonometric Fourier synthesis, program labels, dodge game, rapid descent. Sinclair ZX80, Sinclair ZX81
ZX 81 News and Resources ZX81 hardware expert Bruce Taylor, of Budget Robotics & Computing, has announced the release of his book, Build a Microcomputer-Controlled Robot and Other Computer Control Projects. David Clifford has Westridge 2050 boards available along with Mini-Xmod 1.7; is working on Mini-Xmod for the 2068. Review of Aerco’s FD-ZX Floppy Disk System. British companies supporting the Sinclair ZX81, Timex/Sinclair 1000
ZX Car Race This extremly short program (463 bytes) runs in only 2k of RAM (the standard Timex 1000) and uses all the screen. The keys to steer the car are 0 and 1, located on each side of the keyboard at the top for easy handling. Sinclair ZX81, Timex/Sinclair 1000
ZX Color? Chroma-Soft Review of Russell Electronics’ “experimental software color graphics” that used software tricks to create the illusion of color. Sinclair ZX81, Timex/Sinclair 1000
ZX Destroyer ZX Destroyer is a fast moving action game which is written in a hybrid Basic machine language program to create a continuous, flicker free display. The machine language code routine is a carefully synchronized program loop which controls the laser base, alien ship, and video display. The Basic section provides the initial set-up and ending. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
ZX Disassembler/Debugger Review of Bug Byte’s ZX-81 Disassembler/Debugger (ZX-DB). Sinclair ZX81
ZX Interface Board Input/output interface board that works with either ZX81 or Spectrum. Sinclair ZX81
ZX Interfaces Explained The ins and outs of Sinclair computers. Details are given for the Spectrum as well as the ZX81. Sinclair ZX Spectrum, Sinclair ZX81
ZX is #1 The ZX81 is the best computer to learn about computers and about programming in BASIC or machine code. Sinclair ZX81, Timex/Sinclair 1000
ZX Maze Have you dreamed of writing a graphics game complete with maze, treasure, and gobbling hunter? Perhaps you figured out how to move your man and draw the maze, but how in blazes do you teach your treasure seeker that he cannot just march through walls to collect his prize? Finding a way around this dilemma Sinclair ZX81, Timex/Sinclair 1000
ZX-81 Hi-Res Sinclair ZX81
ZX-81 HiRes Graph Sinclair ZX81
ZX-81 Parallel Printer Interface Sinclair ZX81
ZX-81 POKEs & Calls Sinclair ZX81
ZX-81 taking off in the States THE ZX-81 is beginning to take off in the States. An agreement between Sinclair Research and the American Express credit card company has resulted in a flood of orders for the machine. The credit card company sent a direct mail offer to its two million card-holders in the U.S. at the end of May. In Sinclair ZX81, Timex/Sinclair 1000
ZX-81 Video Display System Sinclair ZX81
ZX-81 Video Display System - Part 1 Sinclair ZX81
ZX-81 Video Display System - Part 2 ZX-TEAM MAGAZIN Sinclair ZX81
ZX-91 Description of Andre Baune’s newsletter. Sinclair ZX81
ZX/81 Schematic Sinclair ZX81
ZX/81/TS 1000 Technical-ities Sinclair ZX81, Timex/Sinclair 1000
ZX/TS Power Supplies Table of details about and schematics of the ZX80, ZX81 and TS1000 power supplies. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
ZX/TS ROM and RAM Addressing Investigation into PEEKing and POKEing outside the 16K-32K address range and how to use a 74LS138 to decode RAM in the 16-32K range. Sinclair ZX81, Timex/Sinclair 1000
ZX80 Check Book Program records up to 10 transactions at a time. Keep them on file by storing the program with the variables intact. Sinclair ZX80, Sinclair ZX81
ZX80/ZX81 Stock Programs Product announcement for programs from M.H. Marks Ent. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
ZX80/ZX81 Users Club The ZX80/ZX81 Users Club in Surrey, England serves all users, beginner to expert. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
ZX81 - Search and Replace Sinclair ZX81, Timex/Sinclair 1000
ZX81 - Sound Analysis Sinclair ZX81, Timex/Sinclair 1000
ZX81 - The New Standard For only $149, you now get 8K BASIC, continuous display, the choice of channel 2 or 3 and a newly styled case. Sinclair ZX81, Timex/Sinclair 1000
ZX81 - TS1000 News Sinclair ZX81, Timex/Sinclair 1000
ZX81 and 16K RAM Schematics A new company, Heuristics, is the exclusive distributor of ZX81 and 16K RAM pack schematics. They also plan ZX81 hardware and software. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Announced in Great Britain An improved version of the ZX80 computer, the ZX81 has been redesigned to incorporate a number of new features. The ZX80 reduced the number of integrated circuits to 21, but the ZX81 further reduces the number of chips to four by using a new custom-built chip that replaces 18 others. The 8k Basic ROM chip Sinclair ZX81
ZX81 Background Reverse Circuit to invert ZX81 video signal, provides white on black. Sinclair ZX81
ZX81 Basic Book Review of the book by Robin Norman. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Basic Compilers Overview of several compilers available in the early 1980s for the ZX81, including ZX Autocoder, MCODER, ZXpress, and The ZX Compiler. Sinclair ZX81
ZX81 Burgler Alarm Sinclair ZX81
ZX81 Calculator Use the Sinclair’s expression evaluator to make a calculator. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Cassette Interface The Winky Board II is a cassette interface for Timex Sinclair computers that filters electrical interference to yeild clean easy loading tapes, has a LED volume level indicator, can save a program on two tape recorders simultaneously, and contains a program duplication system. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Chess vs. ZX Chess II Computer chess is becoming a very popular hobby for those who cannot find opponents on their level, and a large number of ”dedicated” machines are appearing with increasingly greater strengths. Another area of growing popularity is designing a chess program which is more powerful (i.e., a better player) than other chess programs. Two powerful chess Sinclair ZX81, Timex/Sinclair 1000
ZX81 Data Acquisition Module A/D converter for the TS/ZX using the TLC548. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Emulator for the Atari ST Review of emulator. Sinclair ZX81
ZX81 Emulators Sinclair ZX81
ZX81 Extendi-RAM Sinclair ZX81
ZX81 Faster Slow Mode Sinclair ZX81, Timex/Sinclair 1000
ZX81 Faster Slow Mode Sinclair ZX81, Timex/Sinclair 1000
ZX81 Floppies and Interfaces Letter to Steve Ciarcia asking about floppy disk. Ciarcia mentions the FDC-100 ($199) from Compusa. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Games Product announcement for Super Invasion, Wallbusters, Cyborg Wars, Chess, Trek and other games from Softsync. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Hardware and Software News Short notes on ZX81/TS1000. This issue includes brief info on Larken, COMPUSA, Aerco and Oliger 1000/2068 disk systems. Also, why Aerco CP/M was never released. Short reviews of Sinc-Artist for the 2068 and ZX HI-Res. And one user, a Kolorworks owner, mentions writing a TMS9918 toolkit for the ZX81. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Hardware Review (UK) Listing of products and prices for ZX81 hardware. Sinclair ZX81
ZX81 Home Computer Package Lamo-Lem’s Home Computer Package of 4 machine code programs offer a good variety. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Improvements Simple alternatives to hardware modifications for loading/saving problems on the ZX81. Sinclair ZX81
ZX81 Intro Subroutine for use at the beginning of user-friendly programs. Sinclair ZX80, Sinclair ZX81, Timex/Sinclair 1000
ZX81 Keyboard from Memotech The keyboard duplicates Sinclair’s keyboard, but with full-travel keys and an extra shift key in the top right corner. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Logic Signals Reference signal levels for troubleshooting. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Memory Expansion Memotech 64K RAM product announcement and several tapes of software from Sinclair Research. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Mystery Program Sinclair ZX81, Timex/Sinclair 1000
ZX81 Mystery Program Sinclair ZX81, Timex/Sinclair 1000
ZX81 News and Resources Larken Disk system for TS1000, Mini XMODEM 1.7 for ZX81 and TS 2050, Fred Nachbaur’s JOBASIC. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Note Sinclair ZX81, Timex/Sinclair 1000
ZX81 Peripherals EPROM programmer interface from Wisconsinc. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Program Review: Tape Doctor Sinclair ZX81, Timex/Sinclair 1000
ZX81 Reference Card 10-panel, 20-page accordian style card. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Resources Larken LDOS, Eprom Services Programmer, modified version of program that appeared in Compute. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Resources Sinclair ZX81, Timex/Sinclair 1000
ZX81 Resources 1mb Bank-Switched Memory Board. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Resources: 64K SRAM Memory Sinclair ZX81, Timex/Sinclair 1000
ZX81 Resources: A 0 REM Generator Sinclair ZX81, Timex/Sinclair 1000
ZX81 Resources: A Tethered Robot Sinclair ZX81, Timex/Sinclair 1000
ZX81 Resources: Analogue to Digital Converter Sinclair ZX81, Timex/Sinclair 1000
ZX81 Resources: Joysticks Sinclair ZX81, Timex/Sinclair 1000
ZX81 Resources: Moving RAMTOP Sinclair ZX81, Timex/Sinclair 1000
ZX81 Schematic Sinclair ZX81
ZX81 Scroll Clear Sinclair ZX81, Timex/Sinclair 1000
ZX81 Scroll Clear Sinclair ZX81, Timex/Sinclair 1000
ZX81 Software Announcement of Gladstone Electronics catalog. Sinclair ZX81, Timex/Sinclair 1000
ZX81 Tic-Tac-Toe Documentation for the program. Sinclair ZX81
ZX81 Update Update on accessories, software, a BASIC program, notes on the Spectrum, KRAKIT, fast load software, and a machine language program. Sinclair ZX81
ZX81 User-Defined Graphics Small circuit to allow internal RAM to be used for user-defined graphics when the computer has 16K RAM pack attached. Sinclair ZX81
ZX81 Utility Product announcement for Cassette I/O from Cosmonics. Sinclair ZX81, Timex/Sinclair 1000
ZX81, Sinclair Printer News Sinclair has submitted the ZX81 to the FCC for approval for sale in the US. Nigel Searle of Sinclair expects to ship American ZX81s this year, maybe September. Sinclair ZX81, Timex/Sinclair 1000
ZX81: Number Formatting Print Using From “The Art of Programming the 16K ZX81.” Sinclair ZX81, Timex/Sinclair 1000
ZX81: Print Using Sinclair ZX81, Timex/Sinclair 1000
ZX81/Timex Programming in BASIC & Machine Language Takes up where your ZX/TS manual leaves off; the book assumes you know the basics of ZX/TS hardware and software. Sinclair ZX81, Timex/Sinclair 1000
ZX81/TS1000 Software Rating Numeric rating of several software titles. Sinclair ZX81, Timex/Sinclair 1000
ZX81/TS1000 Tips Machine code routine that uses a floating point number as an address. Sinclair ZX81, Timex/Sinclair 1000
ZX81/TS1000 Tips Short machine code routines to save paper when copying a screen, fine the address of a line number. Sinclair ZX81, Timex/Sinclair 1000
ZX81/TS1000 Tips Use a pocket calculator to convert decimal address to hexadecimal and back; program for doing the same on ZX81/TS1000. Sinclair ZX81, Timex/Sinclair 1000
ZXAD: Assembler is full-featured, easy to use Review of the assembler program from Scientific Software. Sinclair ZX81, Timex/Sinclair 1000

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