| 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, Type-in program |
| 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, Type-in program |
| 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, Type-in program |
| 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, Type-in program |
| 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 |
| Galaxy Invaders | In Galaxy Invaders you are under attack by a fleet of enemy spacecraft which you must destroy before they destroy you. This game uses the ZX81’s 1K RAM, graphics, and screen blackout characteristics to produce an arcade type game. | Sinclair ZX80, Type-in program |
| Handling Strings from Another DIMension | The 4K ROM left out the ability to DIMension strings. However, with a few well-placed POKEs, you can plug up that hole in the 4K ROM. | Sinclair ZX80, Type-in program |
| Hardware Tips | Thick Black Bars; Insufficient Filtering Solved; Memory Expansion Power Supply; Ear Input Circuit; Problems with ROM Changing; Top Line Hook Solution; Strong Signals on KBD 0 through KBD 4. | Sinclair ZX80 |
| Just for Fun | Graphics Loop I; Graphics Loop II; Draw It. | Sinclair ZX81, Type-in program |
| 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, Type-in program |
| Letters | LSCROLL, Flag Use, Key and Token Expressions, Hams and the ZX81, ZX80 ROMs, Hardware Suggestion, Inventory | Sinclair ZX81, Type-in program |
| Micro Invaders | In Galaxy Invaders, you are under attack by a fleet of enemy spacecraft which you must destroy before they destroy you. | Sinclair ZX80, Type-in program |
| 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 |
| Resources (Sync v2 n4) | Listing of new user groups, books and other resources. | Timex/Sinclair 1000 |
| Sinclair ZX Spectrum | The Spectrum offers colour, high resolution graphics and sound and, at the price, it has just got to be the best value for the money around. | Sinclair ZX Spectrum |
| Sync Notes | SYNC in Outer Space: Space games lead the list of games that SYNC receives. | |
| 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, Type-in program |
| 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 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 |
| 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 |
| 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, Type-in program |
