Individual Publisher(s): Tim Swenson
Website: http://swensont.epizy.com/
Actively published electronic magazine, produced with open source software. Most issues include a ZIP file with the code, .p files or anything else that accompanies the articles. Published by Tim Swenson.
| Title | Description | Computers |
|---|---|---|
| 1K Othello | Not too long ago I discovered the Dr. Beep did a 1K version of Othello. I thought I would look into the game and see how good it is. The game will play either the white or the black side. It uses high resolution graphics to display the board. The whole game fits into 893 […] | Timex/Sinclair 1000 |
| Aardvark Adventures | Overview of the company and its adventures, short interview with one of the programmers. | Timex/Sinclair 1000 |
| Active T/S 2068 Group | Mention of the groups.io TS2068 group. | Timex/Sinclair 2068 |
| Adding Assembly to BASIC | How-to incorporate assembly into a BASIC program using Linux tools. | Timex/Sinclair 1000, Type-in program |
| Assembly Parameter Passing | I am writing a assembly language routine that needs to send data back to a BASIC program and to get data from a BASIC program. Getting data from the routine is fairly simple if it a single value. Getting data to the routine is more complex as the USR call does not allow for arguments. […] | Timex/Sinclair 1000 |
| Astronomical Algorithms on the ZX81 | Examples of astronomical algorithms from More Uses for Your Timex/Sinclair 1000: Astronomy on Your Computer. | Sinclair ZX81, Type-in program |
| B-1 Bomber for ZX81 | Description of the game. | Timex/Sinclair 1000 |
| Basic Compilers for the T/S 2068 | Brief overview of two BASIC compilers. | Timex/Sinclair 2068 |
| Basic Computer Games | Review of the book by David Ahl. | |
| Basic Tools for T/S 2068 Emulators | Tools to make using the T/S 2068 emulators easier to use. | Timex/Sinclair 2068 |
| Berch Assembler & Disassembler | Review and overview of Bob Berch’s ZX Assembler/Disassembler. | Timex/Sinclair 1000, Type-in program |
| Book Review: ZX Spectrum Assembly Let’s Make a Game? | I have long found it challenging to learn Z80 assembly language. I read Z80 Assembly Language Programming by Lance Leventhal and Programming the Z80 by Rodney Zaks. Both were good but were not specific to the ZX81, so it was difficult to apply what I learned to my computer. | Sinclair ZX Spectrum, Timex/Sinclair 2068 |
| Boriel Basic for ZX Spectrum | With a lot of Open Source programs, finding good documentation can be hard. Juan Duran has fixed that problem for Boriel’s ZX Basic with his recent book. The book was released in December 2023 in Spanish and in English in June 2024. The book is large with 678 pages. | Sinclair ZX Spectrum, Timex/Sinclair 2068 |
| Boriel ZX Basic Compiler | Overview of the compiler with example code. | Timex/Sinclair 2068 |
| Boriel’s ZX BASIC Compiler & T/S 2068 | Notes on adjusting the Boriel compiler to work with the TS 2068. | Timex/Sinclair 2068 |
| Circle | Implementation of Bresenham’s circle algorithm. | Timex/Sinclair 1000, Type-in program |
| Classic Arcade Games from Dr. Beep | Dr. Beep (Johan Koelman) has released 1K versions of two classic arcade games, Asteroids and Missile Command. These games are normal resolution games that fit in 1K (vs his Hi-Res 1K games). | Timex/Sinclair 1000 |
| Comparing ZXbasic and TimeMachine | There are two available BASIC compilers for the T/ S 2068, TimeMachine and ZXbasic. TimeMachine is native on the T/S 2068 and ZXbasic is a cross compiler, written in Python, that runs on Windows, Linux and MacOS. This article will do a short comparision between them. | Timex/Sinclair 2068 |
| Coral Basic Interpreter | Carlos Delhez, writer of Xtricator and Xtender ZX81 emulators, wrote a programming tool that provides an updated version of BASIC for the ZX81, Coral Basic Interpreter (CBI). CBI lets you enter BASIC programs without keyboard entry, meaning that all keywords need to be typed out. | Timex/Sinclair 1000 |
| Dice Problems | I’ve been interested in dice mathematically for years. In wargaming, you win or lose based on the results of a 6-sided die. A role-playing game that I used to tinker with used multiple 6-sided die instead of multiple-sided dice. Back then I wanted to determine a percentile based on a two-die roll. I wrote a […] | Timex/Sinclair 1000 |
| Dice Roller | Implementing polyhedral die roller routines in C with Z88dk. | Sinclair ZX81 |
| Digital Antiquarian | The Digital Antiquarian is a blog written by Jimmy Maher. His main interest is the history of interactive fiction, what was originally known as computer adventure games. He titled his blog with the tag line of “A history of computer entertainment and digital culture.” His blog covers the topic from as far back as 1966 […] | |
| Dr. Lloyd Dreger – T/S 2068 Expert | I have been active in the T/S community since I first joined a user group in 1986. I have subscribed to a number of Sinclair magazines and newsletters since 1982. When I started digging a bit into T/S 2068 assembly programming and the ROM, I was surprised to find the works of Dr. Lloyd Dreger. […] | Timex/Sinclair 2068 |
| Drawing a Line | Code that implement’s Bresenham’s line algorithm in C and BASIC for the ZX81. | Sinclair ZX81, Type-in program |
| Early Mathematical Articles | As mentioned previously, I was drawn to computers for their mathematical side rather than games. When looking through the newsletters that David Anderson has scanned and posted to The Internet Archive, I ran across a number of math articles and I thought I would document them here. | |
| Editorial | Introduction from Tim Swenson, author and publisher. Describes goals and scope of the e-zine. | |
| Editorial | I’ve been having Zoom meeting with other T/S 2068 enthusiasts. David Anderson, who hosts www.timexsinclair.org, started the meetings. He’s been beating the drum of preservation to the team. He’s looking for Timex/Sinclair books, programs, newsletters, etc. to preserve. Some of the meeting attendees have come up with some good documents. | |
| Editorial | At the Timex/Sinclair User Group zoom meetings there has been discussion of a printed magazine with ZXzine suggested as the source. I am hoping to get others to write for this print version to make it more encompassing of the T/S scene. | |
| Editorial | The hard copy of Issue #11 went well. There were a number of people that were part of the T/S group but not regular attendees to the Zoom meetings, for these folks it was a surprise to see the hard copy show up their mailbox. A few copies also made their way to a number […] | |
| Expanding T/S 2068 Software | Thoughts on typing in programs from newsletters. | Timex/Sinclair 2068 |
| Gomoku on the ZX81 | I recently started getting into the game of Gomoku and wrote a paper on the history of computer implementations of Gomoku. I ran across a number of version of Gomoku written in BASIC. | Timex/Sinclair 1000 |
| Harry S. Bluston | I have previously expressed my interest in using Sinclair computers for more serious work and not just playing games. I’ve been collecting any Sinclair related books that are more into the scientific side. While digging around the book archive of the “World of Spectrum” website, I found a couple of books that led me to […] | 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, Type-in program |
| Home Computer Crash of 1983-85 | Describes the impact of the video game and home computer crash, fueled in part by Sinclair and Timex’s computers. | |
| How to Back Your Way Into Learning Z80 Assembly | A bunch of years ago, in the process of building timexsinclair.com, I added some disassemblies of the Timex/Sinclair 2068 ROMs to the site. I was never too happy with them because there were whole passages without comments. A few years later, I added some new disassemblies, one by Bob Orrfelt, the other by Lloyd Dreger. […] | Timex/Sinclair 2068 |
| Imre Auersbacher | With the recent lunar eclipse (March 2025) I was thinking about astronomy software for the T/S 2068. One author that did a program for solar and lunar eclipses was Imre Auersbacher. | Timex/Sinclair 2068 |
| JtyOne | Overview of a ZX81 emulator written in Java. | Timex/Sinclair 1000 |
| Loading a File into Memory | Uses a LOAD command in sz81 to manipulate data. | Timex/Sinclair 1000, Type-in program |
| Loading Screens | Loading screens in the sz81 emulator. | Timex/Sinclair 1000, Type-in program |
| Lunar Eclipses | While scanning some Capital Area Timex Sinclair (CATS) newsletters I ran across this program that will predict lunar eclipses for a given year. All though I found it in the CATS newsletter, the program was originally published in Sinc-Link newsletter by Mel Richardson. The original code was written by Herbert Raab of Austria, using different […] | Timex/Sinclair 2068 |
| Lunar Lander | Recently the book “50 years of Text Games” by Aaron Reed, was released via Kickstarter and I was able to get a copy. The book starts off with some of early and better known text-based computer games (at least for someone that got into computers in the early 80’s). The second game documented is ROCKET, […] | Timex/Sinclair 1000 |
| Mandlebrodt on the T/S 2068 | In looking for something to do I found myself reading back issues of SyncWare News for articles passed over the first time around. The Mandelbrot Plot program in Volume 3 Number 5 caught my eye. Those who read the article by Mr. Nachbaur will remember that the Mandelbrot program creates “computer art”, mathematically created patterns […] | Timex/Sinclair 2068 |
| Memocalc | While trolling the Internet, I came across the ROM file for the Memotech Memocalc expansion unit. I’m always a sucker for another Sinclair spreadsheet, so I downloaded the ROM file and the manual. | Timex/Sinclair 1000 |
| Memory Scan for the ZX81 | n looking through the downloadable programs on timexsinclair.com, I found a memory scan program that provided a graphical view of the contents of memory. I thought I would try something similar for the ZX81. | Timex/Sinclair 1000 |
| Memotech Z80 Assembler | One of the modules that Memotech created for the ZX81 was the Z80 Assembler that plugged into the back of ZX81. The assembler had a menu system that allowed the user to create, edit, list and compile z80 assembler programs. | Timex/Sinclair 1000 |
| MicroAce | History of the MicroAce, a Sinclair ZX80 clone that could be upgrade to be a ZX81 clone. | MicroAce |
| MicroSync Services | Brief article about “Sinclair’s Exclusive Authorized Service Center.” | Sinclair ZX81 |
| Moonphase and Jupiter’s Moons | I’ve done a number of astronomy programs on the ZX81, but really have not ported any to the T/S 2068. I found two programs that would do well with a port and they would benefit from the better graphics on the T/S 2068. | Timex/Sinclair 2068 |
| More Astronomical Programs on the ZX81 | Programs written in C and compiled with z88dk for the ZX81 | Timex/Sinclair 1000, Type-in program |
| MSCRIPT | MSCRIPT is the only word processor that uses the 64 character mode on the T/S 2068. When released it was also the most expensive word process for the T/S 2068. | 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 |
| Orbit | Short program examples that demonstrate an object orbiting another object. | Timex/Sinclair 1000, Type-in program |
| OS-64 | I thought I would tinker with Zebra’s OS-64 cartridge (as a DOCK file) with Zesarux emulator. I have not used it so I wanted to see what it could do. | Timex/Sinclair 2068 |
| Othello | Review of several variations of Othello/Reversi. | Timex/Sinclair 1000 |
| Partial Pascal | Overview of the three-part Pascal compiler/interpreter. | Timex/Sinclair 1000 |
| Plotting with Z88dk | Describes how to add ZX BASIC PLOT/UNPLOT commands to the Z88dk C compiler. | Sinclair ZX81 |
| Porting Assembly from Spectrum to T/S 2068 | Brief notes about ROM differences. | Timex/Sinclair 2068 |
| Prime Number Benchmark | Comparison of prime number benchmarks written in BASIC and C, across several emulators. | Timex/Sinclair 1000, Timex/Sinclair 2068, Type-in program |
| QDDASM – Quick and Dirty DisAssembler | Tim writes his own disassembler. | Timex/Sinclair 1000, Type-in program |
| QDDASM2 | Tim improves his disassembler. | Timex/Sinclair 2068, Type-in program |
| QZX Newsletter | QZX newsletter was a Sinclair newsletter for folks that like HAM or amateur radios. The idea was to combine radios with Sinclair computers. | Timex/Sinclair 1000 |
| Random Number with Assembly | Test of five random number algorithms. | Timex/Sinclair 1000, Type-in program |
| renum.pl | As I was reading some computer history articles, I was thinking about porting some older BASIC software to Sinclair systems. I was looking at ELIZA, “The Oregon Trail”, and others. When looking at these programs, modifications must be made to convert the syntax of the BASIC programs to meet the syntax of Sinclair BASIC. | |
| Saving Screen Blocks | Two routines for saving and loading a block of memory to/from an array. | Timex/Sinclair 1000, Type-in program |
| Sinclair BASICs: DEF FN | This is a look at the DEF FN keyword of Sinclair BASIC and its companion function FN because it was a feature I used very little, and that I recently dug into and found some surprises. | Timex/Sinclair 2068 |
| SoftSync | Sue Currier came from Australia to the United States to pursue a career in modeling. She was discovered by the Eileen Ford Agency in Melbourne. She flew to New York City to sign with them and worked with them from 1971 to 1974. In 1974, Sue married Ken Currier on the 86th floor Observation deck […] | Timex/Sinclair 1000 |
| Solving a Maze with Cellular Automata | Implementation of Basem Nayfeh’s cellular automata rules to solve a maze. | Timex/Sinclair 1000, Type-in program |
| Sound Players | Programs that support the Zon-X81 sound system. | Timex/Sinclair 1000 |
| Sound Tester | I thought about playing more with sound on the ZX81 or T/S 2068. The Zon X-81 and the T/S 2068 both use the AY-3-8910 Programmable Sound Generator (PSG) and they both interface with the PSG by using the PSG registers, so any sound settings will be usable on both. I tried the SOUND command on […] | Timex/Sinclair 1000, Timex/Sinclair 2068 |
| Structured Programming with ZX81 BASIC | Discussion of structured programming techniques and how to apply them to the ZX81 | Timex/Sinclair 1000 |
| sz81 Emulator | Review and how to use the emulator. | Timex/Sinclair 1000 |
| T/S 1510 & Cartridge Clone | When the T/S 1500 was released, Timex also released the T/S 1510 cartridge system. The T/S 1510 was a cartridge dock that plugged into a 1500 or 1000. Game cartridges were then plugged into the dock and when the 1500 was powered up, the game on the cartridge started up. For the 1000, a USR […] | Timex/Sinclair 1000, Timex/Sinclair 1500 |
| T/S 2068 and ZX81 ROM Routines | Comparison of routines in both computers. | Timex/Sinclair 1000, Timex/Sinclair 2068 |
| T/S 2068 Assembly Language Programming | Overview of using Pasmo to compile assembly language programs for the TS 2068. | Timex/Sinclair 2068 |
| T/S 2068 Emulators | Overview of several emulators. | Timex/Sinclair 2068 |
| T/S 2068 Fonts | One feature of the T/S 2068 that I had never tinkered with is using a different font. I knew a number of Spectrum games that used a different font, but I had not thought about it on the T/S 2068. The general process is the same on the T/S 2068 as it is on the […] | Timex/Sinclair 2068 |
| T/S 2068 ROM Disassembly | Tim begins disassembling the TS 2068 ROM with QDDASM2, his disassembler. | Timex/Sinclair 2068 |
| T/S 2068 Specifications | Description of features that differentiated the TS 2068 from the ZX Spectrum. | Timex/Sinclair 2068 |
| The TS Pico: A Modern Storage System for the Timex/Sinclair 2068 | The TS Pico story starts in 2021, when Ricardo Calcagno emailed me to ask if anyone had designed a modern alternative to the disk systems that were once available for the Timex/Sinclair 2068. | Timex/Sinclair 2068 |
| 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 |
| Three Games Ported from Speccy to T/S 2068 | I had the urge to port a few more games from the Speccy to the T/S 2068. This time I wanted to do more than just a demo game. I browsed the web looking for Spectrum games with assembly source code. I ran across two programs from Jonathan Cauldwell, Area 51 and Turbomania. | Sinclair ZX Spectrum, Timex/Sinclair 2068 |
| Time Designs Magazine | Overview of the magazine and its history. | Timex/Sinclair 1000 |
| TimeMachine on Zesarux | I thought I would take another crack at TimeMachine, the Basic compiler for the T/S 2068 and with some pointers from David Anderson, I was able to get it working. Here is how I got it working on Zesarux. | Timex/Sinclair 2068 |
| Timer in Assembly | While working on a game project, I needed a way to time what a user was doing, all in Z80 assembly. The ZX81 does not have a clock mechanism, but it has something close. | Timex/Sinclair 1000 |
| Timex Sinclair 2068 History | Review of the history of the computer. | Timex/Sinclair 2068 |
| Timex/Sinclair Crossword | A fun crossword featuring the Timex/Sinclair computers. | |
| Toby Radloff | Brief article about the minor MTV celebrity and TS 2068 user. | |
| Tom Bent’s Improved ROM | In early 1985, Tom Bent released an EPROM with an upgraded version of the ZX81/T/S 1000 ROM. It was released as the “Sinclair ZX 8K ROM Upgrade”. The package contained an EPROM and an adapter board to fit the ROM into the socket of the old ROM. | Timex/Sinclair 1000 |
| tsmake | Linux shell script to convert TS 2068 keywords to characters that zmakebas can process. | Timex/Sinclair 2068, Type-in program |
| Two Books on BASIC | In the last year I picked up two books by Mark Jones Lorenzo, “Endless Loop: The History of the BASIC Programming Language” and “Gosub Without Return: Between the Lines of the BASIC Programming Language.” | |
| Typing in Assembly | Four assembly language programs that demonstrate accepting user input via the keyboard. | Timex/Sinclair 1000, Type-in program |
| UDG Character Generator | While scanning some TimeLinez newsletters, I came across an book review by Walt Gaby of the book “Timex Sinclair Color Graphics” by Nick Hampshire. In his review, Walt included a program that helps define the codes needed with User Defined Graphics (UDGs). Having touched on T/S 2068 fonts (which are similar to UDGs), I thought […] | Timex/Sinclair 2068 |
| US ZX81 and T/S 1000 Hardware | I’m not much into hardware, but I believe that things should be documented. After some discussions during the T/S group Zoom meetings, I thought I would see about documenting some ZX81 and T/S 1000 hardware aspects. On the Sinclair ZX World forums there is a fair bit of information about ZX81’s. Those folks are much […] | Sinclair ZX81, Timex/Sinclair 1000 |
| Using HRG-ms | Overview of a high-resolution toolkit for the ZX81 by Matthias Swatosch. | Sinclair ZX81 |
| VuCalc | Overview of Vu-Calc, a spreadsheet for the ZX81/TS1000. | Sinclair ZX81 |
| VuCalc vs VisiCalc | Comparison two spreadsheets. | Timex/Sinclair 2068 |
| Wireframe for T/S 2068 | Back in college I took a Computer Graphics class. One of the items covered was wireframe 3D graphics (well, 3D showing in 2D). I wrote a program for the QL using the technique used in the book from that class. I decided to port the program over to the T/S 2068. | Timex/Sinclair 2068 |
| z80asm | Short introduction to the z80asm assembler. | Timex/Sinclair 1000 |
| z80dasm | Short review and how-to use the z80dasm disassembler. | Timex/Sinclair 1000 |
| zeditor | Review of a high-resolution word processor for the ZX81. | Timex/Sinclair 1000 |
| ZX81 “Mouse” | Something recently got me thinking about having a mouse on a ZX81. At first I was thinking of a traditional mouse with a movable arrow. This might be possible with hi-res graphics, but I’ve never tried using hi-res graphics. | 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 Fonts | After tinkering with fonts on the T/S 2068, I was wondering if something could be done on the ZX81 to change its fonts. The ZX81 does not have a way to define a new font, so another method would have to be tried.. Since I am using emulators, the ZX81 ROM is really nothing more […] | Timex/Sinclair 1000 |
| ZX81 in Science | Review of academic papers that cite using the ZX81. | Timex/Sinclair 1000 |
| ZX81 Resources on the Internet Archive | Summary of magazines and newsletters. | Timex/Sinclair 1000 |
| ZX81 Software Documents | I like good documentation. With the QL, as I used different software, like the Small-C or C68 compilers, I reformatted their documentation with a word processor like OpenOffice. This produced a nice, professional looking document. | |
| ZXBETA User Guide and Tutorial | ZXBETA is a music tracker software for the ZX81 with the ZonX-81 sound system. The user guide and tutorial was published on my website a few months after the last issue of ZXzine, but I thought I would document it here for those that might have missed the announcement. | Timex/Sinclair 1000 |
| zxpaint2 | Program to convert output from ZXpaintyone to a BASIC program. | Timex/Sinclair 1000, Type-in program |
| ZXPaint3 | I’ve been using the tool ZXPaintyOne to create ZX81 graphics. The tool creates a long string of numbers to represent the value of the characters painted on the screen. I wrote zxpaintl.c to take the output of ZXPaintyOne and create a screen file (.scr) that could be directly loaded into the ZX81. I wrote zxpaint2.c […] | Timex/Sinclair 1000 |
| ZXpaintyOne | Converting ZXpaintyOne save files to load in sz81. | Timex/Sinclair 1000, Type-in program |
Last updated: January 14, 2026