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
Arithmetic Series Quiz Read More »
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.
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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
Understanding Your ZX81 ROM Read More »
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.
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.
Understanding Floating-point Arithmetic, Part 3 Read More »
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.
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
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.
Two Switch Human Interface for the Communicative Impaired Read More »
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.
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
An Introduction to Expression Evaluation Read More »
