Articles about the ZX80

  • "You Are in a Maze..."
    “…of twisty little passages, all alike.” This message, in Adventure of Zork, tells you that you have embarked on one of the most challenging phases of the game: mapping the maze and finding your way out. Even without the rest of the dungeon, a maze can make an exciting puzzle in itself —especially if there
  • [The 8K ROM produces a different screen display than the 4K ROM.]
  • 16K RAM Approved; New Interface
    Federal Communications Commission (FCC) approved Sinclair’s 16K RAM for the U.S. market. C.A.I. Instruments has completed work on three interfaces.
  • 30 Programs for the Sinclair ZX-80 - a Review
    Review of the book published by Melbourne House.
  • 4K Programs on 8K ROM
    8K ROM won’t load 4K tapes.
  • 4K RAM Units Available Soon
    Static Memory Systems will sell 4K RAM packs for ZX80s and MicroAces.
  • 4K ROM Listing - Initialization
    Computer initialization routine in 4K ROM.
  • 4K ROM: Display Routine
    DISPLAY begins the 4K ROM’s input/output module at 013Ch, or 316d.
  • 4K/1K Blackjack
    In this 4K/1K ZX80 version of 21 you play one-on-one against the computer-dealer. It deals you two cards face up. To take another card, hit NL; to hold, press SPACE NL. The ZX80 then plays out its hand and shows if you win or lose.
  • 4K/8K ROM Switch
    Review of the ROM switch kit from Marex Electronics.
  • 4K/8K ROMs in One ZX-80
    This article describes the final solution that I used to make both ROMs available to my ZX80. 1 installed the ROMs piggyback in the socket and switch selected the ROM to be used. The modification is very simple and requires only a soldering iron, an spdt switch, and a few inches of wire.
  • 8K Basic ROM
    While the 4K Integer Basic in the Sinclair ZX80 is adequate for many applications, most programmers will eventually feel a hunger for more power. True, advanced functions can be simulated by way of subroutines, but such measures eat memory at an alarming rate. Enter the 8K Basic ROM. The chip costs a mere $39.95, which
  • 8K Basic ROM and 16K-Byte RAM Pack Specifications
  • 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
  • 8K ROM Changes
    Revisions to previous programs for 8K ROM.
  • 8K ROM Printer Commands
    LLIST — Lists to printer instead of screen, LPRINT — Directs output to printer instead of screen, COPY — Outputs screen display to printer.
  • 8K ROM Programs Here!
    Our technical staff has the only prototype 8K ROM in the U.S. and we’re wording on programs so you will be able to use your new ROM immediately. We’re especially impressed by the graphics capability and the PLOT-DRAW-PRINT sequence.
  • 8K ROM Update
    Sinclair now has another source of 8K ROMs. According to Nigel Searle, the new manufacturer will deliver by September 1 enough ROMs to both replace bad ROMs and satisfy demand for new ones.
  • 8K ROM Updates
    Updates to Hurkle, Castle Doors, Nichomachus and Widget for the 8K ROM.
  • 8K Syntactic Sum
    Modified version for 8K ROM.
  • 8K/1K Slot Machine
    Another free sample software review—a program directly from New England Software’s tape.
  • A Microcomputer Timeline
    Timeline from pre-1974 to 1985. ZX80 mentioned.
  • 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.
  • A Night in Las Vegas
    Review of the cassette from Lamo-Lem.
  • A Parallel Interface for the ZX-80/MicroAce Computer
    Construct a simple parallel interface for the ZX80/MicroAce computers with the Z-80 PIO.
  • A Subroutine for Serial Data Output
    Trying to write machine code subroutines for the ZX80 presented some problems. This article details the problems with their solutions, and shows a simple subroutine to output data serially by bit to an asynchronous peripheral.
  • 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.
  • A Trick and a Graphic System
  • A Weekend With the ZX-80
    With just two weekends of not terribly intensive study, I can run just about any pre-programmed cassette, as well as doing some of my own programming. I am no programmer, but I do find that I can have a lot of fun playing games or learning on the ZX-80. It is such an easy machine
  • Acey Ducey
    Simulation of the Acey Ducey card game. In the game, the dealer (the computer), deals two cards face up. You have an option to bet or not to bet depending whether or not you feel the next card dealt will have a value between the first two.
  • Add a Full-Sized Keyboard to Sinclair's ZX80
    Interface a surplus keyboard to the ZX80.
  • Adding an LED Load Monitor to the ZX80
    Single LED (light emitting diode) added to the tape “ear” input of the computer. The voltage for lighting the LED is just right for loading a program from the cassette tape.
  • Addition Through 7 Digits
    Add 7 digit numbers as long as the total doesn’t exceed 7 digits.
  • Address and Phone Book
    This 4k program stores ASCII as codes into an array, getting areund the 4K BASIC’s lack of string arrays. It stores and prints names and addresses one at a time. This program runs in a 2K machine; for 1K RAM reduce DIM A.
  • All-Purpose Beeper
    Circuit to emit a “beep” every time your ZX80 or MicroAce reads from or writes to a selected memory address.
  • An Alternative Display Method - Tank Battle
    This game itself inspired by Lloyd Johnson’s article “Paint Duel” in Creative Computing (July 1981). The player attempts to destroy the computer’s tank by hitting it with a well-placed shot.
  • An Interview with Alfred Milgram
    Alfred Milgram, president of Melbourne House and David Ahl chat about the ZX80, Sinclair Research, and two new books.
  • 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.
  • An Introduction to Machine Code
    How to start using machine code on the ZX80/81.
  • Annotated 4K ROM Listing
    The 4K ROM SAVE routine listing, including the original designer’s notes.
  • Annotated 4K ROM Listing - Systems Variables
    Listing tells you the values of all major variables used in the 4K ROM.
  • Annotated 4K ROM: LOAD Routine
    Assembly for the 4K ROM’s LOAD routine. LOAD begins in ROM location 0206H, or 518d.
  • 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
  • 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.
  • Artillery
  • Ask BYTE: Other Keyboards for the ZX80
    Writer wants to know if ZX81 keyboard can be expanded based on article in March 1982 issue of Byte.
  • Atmospheric Perturbation?
    Letter defending the ZX80 as reviewed by John Palmer.
  • Authorized Software
    Image Computer Products of Northbrook, IL, is the authorized ZX80 software producer.
  • Auto-Display-Changing
    How Is It Done? A series of articles.
  • Automatic Recorder Control
    Call the LOAD routine directly.
  • Bar Graphics
    This program, written for a 2K MicroAce, draws bar charts on a white background with dark defined lines and a graphpaper-like effect behind the bars. It will choose 10 (0 to 10) random numbers to graph, or you can select them.
  • Basic Salary Scheduling
    Calculate salaries that increment on a straight-line basis.
  • Battleship Solitaire
    This Battleship Solitaire program allows you to play a similar game against the computer, but with the modification that you do all the shooting. Even though you have no ships to be sunk, you are still subject to penalties. Each time you fail to score at least one hit per salvo you lose one shot.
  • 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.
  • Beginner's Column - Error Codes and Debugging Programs
    One of the ZX80/MicroAce’s nicest features keeps you from entering lines with syntactic errors into a program.
  • Beginner's Loading ML Programs
    Learn how to put machine language (ML) programs into your computer.
  • Beginner's ROM and RAM Addresses
    ROM and RAM addresses in 4K ROM, 1K RAM machines.
  • Beginners - Analyzing the Problem
    The first step in solving a problem with a computer is analyzing how you would solve it without one.
  • Beginners: User-Friendly Programs
    Some easy programming methods to write user-friendly programs for either 4K or 8K ROM programs.
  • Beginners' Column: REM Revisited
    Storing machine code in REM statements.
  • Beginners' Dimensioned Arrays
    Although BASIC uses simple English commands, the DIM statement is one of those that takes a little explanation.
  • Beginners' ML -- Register to Register
    Examines the loading, adding and subtracting instructions. Number 5 in series.
  • Beginning Programs -- For-Next Loops
    For-next loops consist of 2 control statements, FOR.. TO and NEXT. These allow you to tell the computer to do a maximum number of steps in a minimum number of commands when you need the same calculation carried out several times with different variables.
  • Best of Sync, Volume 1
    Review of the book that collected articles from the first year of Sync magazine.
  • Big Character Program
    Make your video characters 8 times bigger using ROM character images and substituting graphic symbols for dots.
  • Binary Representation
    Knowing how to manipulate individual bits in your ZX80 is essential for efficient Machine Code programmming, so knowing what bits and bytes are is essential also.
  • Bingo Number Generator
    Generates numbers with their preceding letters and prints them at 8x their normal size at the top of the screen.
  • Bisection Interation Square Root Program
    This program operates by means of bisection iteration, which is basically just a variation of the old high-low game. The size limitation of the integer basic (variable size) limits the maximum root to 181.
  • Black Hole
    Game based on an Elf (RCA 1802) machine language program.
  • 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
  • Boston Show Surveyed
    The tiny Sinclair ZX80 was a popular item. Sinclair’s Nigel Searle was pleased with its present sales and is making plans for the introduction of its 8K ROM BASIC, as well as a modem and low-cost printer in 1981. FCC certification procedures are holding up the 16K add-on RAM.
  • Bubble Sort Routine
    Sorts numbers into ascending order.
  • Build Additional RAM
    How to upgrade the ZX80 to 8K RAM.
  • Bytesavers Hint
    If you are using a PRINT after a line number simply to add an empty line, use two commas instead.
  • CAI Instrument's Widget Board
    Most of us are pretty tired of waiting up to a year for delivery and then getting equipment and manuals with obvious mistakes. Couple that with an unresponsive manufacturer and you get frustrated customers. Because of problems detailed below, SYNTAX recommends that you delay purchasing the Widget until CAI Instruments offers correct, complete, and consistent
  • CAI Printer Update
    CAI Instruments will offer software components to make their Widget printer compatible with both 4K and 8K ROMs.
  • Cannonade
    In Cannonade you are the commander (choose your own rank) of a squad of six men. You have been given as your next objective the capture of an enemy gun emplacement. Your men must outmaneuver the gun’s handlers. If they are spotted as they are advancing, they may be fired upon. When a man is
  • Cassette Eavesdropper
    Use this simple circuit to listen to your programs as they save and load or to search for programs on tape without pulling the earphone cord and adjusting the volume control each time.
  • Castle Doors
    Castle doors is an adventure game that presents a new challenge with each playing, and the opportunity for easy adjustment of difficulty if the Wizard is winning too much, or too little of the time. You, the player, have the ultimate task of defeating the evil Wizard, but first you must gain strength and experience
  • Changes to Amazing Active Display
    John Sampson of College Point, NY, called in response to the letter in the Oct. 81 issue about The Amazing Active Display.
  • Changes to September Budget Program
    User interface changes to the program.
  • Changes to Super ZX80 Invasion
    Add new levels of difficulty.
  • Character Reverse
    Have you ever wanted to put a reverse character in a string but you had no way of doing it? Here is a simple answer, a small machine language program that will reverse a character for you.
  • Chart Your Biorhythms
    Program for 8K ROM machines graphically displays your emotional, intellectual and physical cycles.
  • 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
  • Chest of Classics by Lamo-Lem
    Review of the programs from Lamo-Lem.
  • Christmas Buyers Guide
    Comparison of computers available in December, 1980.
  • 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
  • Coming to Terms
    Response to Langdon Proctor’s letter.
  • Comparison Between The Sinclair ZX80 and The TRS-80 Color Computer
    Table comparing the various hardware and programming language features.
  • Comparison Between the Sinclair ZX80 and the TRS-80 Pocket Computer
  • Compu-Calendar
    This three-part program returns correct day name, changes Gregorian dates to corresponding Julian day numbers, and computes total days between any two dates from Jan. 1 AD to Feb. 2300.
  • Computer controllers: Adapting the Sinclair ZX-80 for laboratory use
    Differences between the MicroAce and Sinclair ZX-80 are described. Adaptation of the Sinclair ZX-80 for a previously described laboratory control function is discussed.
  • Computer Models
    Programming tutorial on calculating buinsess models wide variety of cases.
  • Computer Number Systems
    Introduction to binary with programs to convert from decimal to binary and binary to decimal.
  • Computer Number Systems II
    Examines hexadecimal system.
  • Computer Number Systems III
    Article looks at octal numbers.
  • Computers and Society
    Among the several new computers introduced at the June CES, one of the most interesting entries was the Sinclair ZX-80. This Z-80-based computer (which weighs only slightly more than its instruction manual (320 g vs. 250 g)) contains a full typewriter-like keyboard (membrane type), 1 KB of RAM and a 4 KB BASIC.
  • Continuous Display Utility
    Want a flicker-free screen? JRS Software now offers software for continuous display.
  • Converting From Other Basics
    While Basic is a distinct computer language , it exists in many forms. Thus, a program written for another machine might have to be converted before it will work with the Sinclair. This series will deal with conversion techniques, in hopes of allowing you to get as many programs as possible running.
  • Create a Word Search Puzzle
    By using this program in the ZX80 or MicroAce, you can create your own 15 by 11 character word puzzles and have fun solving them or give them to your friends to solve.
  • Credit Due to Personal Computer World
    Follow-up to December 1980 review of ZX80, noting it was a reprint of an article from Personal Computer World, a British publication.
  • Cryptoquote -- Use Your ZX80 to Help You Solve Substitution Ciphers
    “Cryptoquote” is a program for infinitely patient or just masochistic puzzle-solvers. It works just like cryptoquotes in newspapers — you substitute letters for letters to decode the babble into a quotation. Your ZX80 will help you, though, by displaying the frequency distribution of letters in your quotation.
  • Data Dubber
    The Peripheral People offer a device to help you LOAD and SAVE cleanly.
  • Data File Format
    Here’s a program for 2K MicroAces that allows you to create indexed files on tape.
  • DATA Statement Simulation
  • Dealing Out a Conversion
    Sinclair owners will probably spend a fair amount of time converting programs from other Basics. This can be a rewarding and educational practice or an exercise in frustration, depending on how you go about it.
  • 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.
  • Dear Editor
    MicroAce 8K ROM and flicker-free video upgrade board. ZX81 glitches. RAM pack wobble.
  • Dear Editor
    Letters about adapting the ZX80 to work worldwide; beginner questions about programming; request for 8K ROM listing; recorders.
  • Dear Editor
    ZX-Microfair in London; Microace 8K ROM has bugs; Microace regulator; floating point in 8K ROM.
  • Dear Sinclair Research
    It is with great displeasure that I am returning my Sinclair ZX80. Response from Nigel Searle.
  • Defuse
    You are the Chief of Security in a major government building. You have just received a telephone message from a terrorist group claiming that they have planted a bomb somewhere in the building. Fortunately, you have the most sophisticated electronic detection equipment available. Your detector gives off a signal that gets stronger as you get
  • Detective
    A murder has been committed and the perpetrator has threatened to strike again! It is up to you to uncover the two pieces of evidence which will identify the murderer before he can carry out his threat. The game consists of searching the 4 rooms in the building where the crime occurred for the incriminating
  • 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,
  • Dice Roll
    This program turns your ZX80 into a totally fair dice roller.
  • Different Strokes
    Prestodigitizer, an 8-bit input graphics tablet available for several micros, will soon be ready for your ZX80.
  • Disassembled BASIC - A Review
    Linsac has published a disassembled listing of the Sinclair Basic.
  • Draw a Picture
    Simple program from 30 Programs for the ZX-80.
  • Edge Connectors Available
    Kopak Creations of New York now offers 46-pin edge connectors for ZX80/81s.
  • Editorial
    The Sinclair ZX80 is the new kid in town; a short-lived position in this rapidly changing field. In the past few years, several dozen personal computers have made an appearance. Some are thriving, others have fallen into the obscurity of bargain sales. We believe that the Sinclair is going to be one of the winners;
  • Editorial: The best of times, the worst of times...
    Well, the worst is over and it can only get better. At least that’s how I -feel now as I tap out my -first newsletter on my 2068. I wish to thank all of you who have decided to stick with the newsletter (and, of course, the ZX computers) for your continued support – I
  • Educational Software Vendor
    Edson Electronics offers educational programs for ZX80/81.
  • 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
  • Equational And/Or
    Many users are confused about the logical use of AND and OR in the 8K ROM. Here is a touchstone (demonstration) program illustrates various uses of AND and OR.
  • Estimate Heating Costs
    Use these 3 programs to estimate heating costs for houses and other small buildings.
  • Examining Prime Numbers: Two Programs
    The first of the two programs below tests a set of numbers to see which members of the set are primes. The program asks for (and enters with INPUT statements) the beginning and the end of the set and displays those numbers in the chosen set which are primes.
  • 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.
  • Experiments in Memory and I/O Expansion
    How memory works in the ZX80; adding RAM using 2114 chips; adding I/O; adding RAM using HM6116 CMOS chips.
  • Expression Evaluators at Work
    Reprint of the article from the first Kitchen Sync column.
  • Extended ZX80 Service Contracts
    Sinclair now offers extended service contracts to ZX80 owners. $25 per year will cover all parts and labor and return shipment of the unit.
  • EZUG Newsletter
    The Educational ZX80/1 Users’ Group (EZUG) publishes a newsletter each month for ZX80 users.
  • Flicker-free Four Times Normal Character Scrolling
    Programming an active display without the flicker and flash is one of the challenges confronting the ZX80 user. So far the programs published in SYNC with flicker free display possibilities have some limitations: 1) the program must stay in machine language; 2) all computing must be done during the vertical blacking period; or 3) everything
  • For Syntax Readers Only
    Sinclair now offers used ZX80s for only $49.95. According to Nigel Searle of Sinclair, most of these machines were sold in England as kits and assembled incorrectly.
  • Forest Treasure
    “Forest Treasure” is based upon “Random Graphics” by Gary McGath in the Jan/Feb 1981 issue of SYNC. You are riding through a forest, seeking the gold treasure. You are represented by “£” and the treasure is a blank space. During your ride you may encounter enchanted (invisible) walls. When touched, these walls will alter your
  • Frequency Histogram
    Program tests how random the ZX80/MicroAce’s random number generator really is.
  • From Other Basics - VAL and LEN
    ZX80 Basic substitutions for LEN and VAL functions.
  • From Sinclair Research
    Sinclair ZX80 and Syntax ZX80 announcement.
  • Full Annotated 4K ROM Listing
    Sinclair’s complete 4K ROM listing with original designer’s annotations will be available from SYNTAX by August.
  • 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.
  • Game of Life
  • Gauntlet
    Gauntlet is a game played on a rectangle 19 spaces by 6 spaces. The object is to run a gauntlet of random obstacles and monsters, beginning on the left side and crossing the rectangle. You win when you have successfully moved your marker to the right side.
  • Getting Loaded
    Tape loading monitor. The monitor consists of two LEDs, a diode, some wire, and a case to house everything. The number 1 LED acts as an indicator of too low a volume or of the correct volume. The number 2 LED is an indicator of volume which is too loud.
  • Glitchoidz Report
    Corrections to errors, problems and other Glitchoid activities discovered in prior articles.
  • Glitchoidz Report
    Corrections to Widget (Sync v1 n2), Looking inside the ZX80 (v1 n3), A Trick and a Graphic System (v1 n3), Perceptions (v1 n5), Gra+Pix (v1 n4), and Hangman (v1 n4).
  • Glitchoidz Report
    Corrections to GRA+PIX; Mini-Billboard; The PEEK Function and POKE Command; An Inventory System; The Hidden Chessmen.
  • Gradebook for Teachers
    Program helps teachers average grades at the end of the grading period.
  • Graphics Surprises
    When we combine the uncertainty of the ZX80’s randomizing feature with its graphics capacities, we have the ingredients for a lot of fun. For example, the Crazy Quilt program uses only two instructions, yet it fills the screen with a zany tangle of symbols and spots. A more challenging application of graphics and randomizing is
  • Graphics, Games and Gold
    Graphic adventure game: the hero roams within a randomly generated wood, cave or castle, encountering monsters and treasures.
  • Hammurabi in 1k
    Player manages an economy.
  • Hampson's Plane
    Program translates the three dimensional Rubik’s Cube to the two dimensional TV screen via the ZX80.
  • Handling Character Strings in the ZX80
    Using USR(47) to find the address of a string variable and peeks/pokes to manipulate the string.
  • 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.
  • 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
  • Hangman
    ZX80 version of the 2 person spelling game, Hangman.
  • Hardware Helpers
    Reset button, high contrast inverse video.
  • Hardware Hints
    Potential solution to overheating; labeling keys on big keyboards.
  • Hardware Notes
    Advice on DIP headers; edge connectors; video monitors; reset switch; cassette monitoring.
  • Hardware Report
    Potential solution to problems with LOAD.
  • 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.
  • Hardware Tips
    Robert Hartung comments on some letters from readers. His responses should be regarded as suggestions to help look for the answers.
  • Hexloader
  • Hog Heaven - ROM Entry Points
    Complete list of global subroutine calls for the 4K ROM’s eigh software modules.
  • House of Horrors
    You are trapped in the dreaded “House of Horrors.” Naturally it is filled with monsters, mummies, skeletons, and strange creatures. Secret passages and mysterious rooms confront you with danger and yet offer the only way out. Your goal is to escape from the house alive.
  • 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
  • How Many Bytes to the Line?
    Subroutine determines the exact number of bytes used for each line of program instruction as well as an entire program.
  • How to Invent a Game - Inside Flattop Lander (MCD)
    The conception and initial game design of Flattop Lander and the Machine Code subroutine that will produce an instant display.
  • How to Invent a Game, Part 2
    Finishing the programming for the game.
  • How to Produce a Display File Using Machine Code
    In the ZX80 the display file is the part of the RAM which holds the next picture to be shown. A complete picture is made up of 24 lines which can be from to 32 characters in length. The display file has an initial delimiting “118”. and another delimiting “118” to mark the end of
  • How to Wire a Big Keyboard
    Although the ZX80 has many fine features, some people complain about the small pads of the touch keyboard that comes with it. But this is not a serious problem. The ZX80 uses a matrixed keyboard, so you can easily add a bigger, parallel keyboard.
  • Hurkle
    Game converted to ZX80.
  • 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.
  • Important Information for Cassette Use
    Suggestions for better LOAD/SAVE.
  • Improved 4K Sine Calculation
    Use these lines in 4K programs requiring sines between 0 and 90 degrees.
  • Improving Display
    One problem with creating graphic displays on the ZX80 is users’ inability to interact with display. This program allows you to manipulate a cursor on 14 screen lines and to insert characters where desired.
  • 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.
  • Increment, Decrement For-To's
    Use LET to increment or decrement loops in 4K BASIC.
  • InfoNews/Software: Super Z
    Super Z for the ZX80 and MicroAce computers adds seven new statements to Sinclair 4K BASIC: TAB, SCROLL, MEM, PAUSE, READ, RESTORE and DATA. The statements are contained in a machine-code module that’s loaded at line 0 and is invisible to users.
  • InfoNews/Software: Super ZX80 Invasion, Double Breakout
    Super ZX80 Invasion, a 1K game for the Sinclair ZX80 personal computer, has recently been introduced by Softsync, Inc. The game engages the player in battle against space invaders attacking in battle formation. Softsync is offering Double Breakout, also a 1K game with moving graphics for the Sinclair computer.
  • InfoNews/Software: Wall Busters
    Wall Busters is a fast computer ball game by Softsync for the 1K Sinclair ZX80 computer. You are challenged to hit a ball with a movable bat and chip away at a brick wall. Players can choose from seven levels of speed and skill. Wall Busters is compatible with both the Sinclair ZX80 and MicroAce
  • InfoNews/Software: ZX80 Business Package
    The ZX80 Business Package by Lamo-Lem is for the Sinclair ZX80 or MicroAce computers. The package includes Search & Save, which allows storage of text files on cassette and retrieval by keyword or phrase; VideoComp-4, which displays a worksheet of three columns and uses a keyboard overlay to perform operations involving entire columns; and VideoGraph,
  • Input Port
    Capture data through a port, place it into a CPU register.
  • Interface to the Real World
    Add an 8-bit latch to the ZX80 or MicroAce, mapped to 3000H (12288). Includes schematic.
  • Interview with Clive Sinclair
    Clive Sinclair is the man behind the first mass pocket calculator, the first scientific calculator kit and, now, a mass-market computer. David Ahl talked to Clive while in London at the PCW show.
  • Intro to Machine Language
    Start of series on machine language programming for beginners.
  • Inverse Big Characters
    To print 8x size characters in reverse video, change these lines from Big Characters (Dec. 80).
  • Inverse Cryptology
    Challenging code breaking game for 2 uses 4K ROM and 1K RAM.
  • Isolation
    In Isolation you attempt to encircle one of the computer’s men, isolating him from all of his cohorts. A man is isolated when you have placed one of your men above, below, to the left, to the right and in the four locations diagonally adjacent to the victim. Therefore, a man located in a corner
  • Just for Fun
    Renumbering by a USR Routine; Sweeper; Ed, the Head.
  • Key Click Generator
    This simple circuit will produce an audible tone whenever the ZX80 screen is blanked, yielding a click to indicate key closure, or a steady tone during processing.
  • Keyboard Beeper
    Simple device that beeps when a key is pressed.
  • Keyboard Beeper
    Review of Burnett Electronics’ keyboard beeper.
  • 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.
  • Kitchen Sync
    Discussion of the ZX80 BASIC expression evaluator.
  • Kitchen Sync
    This month’s column was inspired by two other articles appearing in the May/June issue of SYNC. In the first, David Lubar told of his experiences in using the NOT operator of Sinclair Basic. In the second article. Bill Eckel introduced a game called Black Hole and presented a version which he “almost” got to fit
  • 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
  • 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.
  • 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.
  • Know Your Gas Hogs
    Use your ZX80 to compare fuel economies and estimate total gas expenditures.
  • Landing a LEM on the Moon
    This ZX80 version sets a LEM 2,530 meters above the moon with only 300 liters of fuel. You must land without crashing or running out of fuel.
  • 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
  • Letters
    Our Face is Red!; Four Tips for MicroAce Owners; Channel 2 Interference Problem Cure.
  • Letters
  • 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.
  • Letters
    8K ROM Double Images; Taxman; An Inventory System; Hampson’s Plane; Flag Use Tip; ZX80/81 World; The Great Circle Route.
  • Letters
    Help Wanted, SGN and Inventory.
  • Letters
    ROMs and RAMS, Memory Saving Tips, The SAVE Signal.
  • Letters to the Editor
    Question about calculating odds; how to translate BASIC programs with READ, DATA, RESTORE; 8K ROM for ZX80 doesn’t give SLOW mode.
  • Letters: More Memory for the ZX80
    Correction to article about expanding ZX80 RAM. Notes on getting ZX80 to recognize 48K.
  • Light Control Interface
    Interface Technology will adapt “The Microcommander” to the Sinclair ZX80.
  • Lights of the City
    This program uses the 8K ROM’s graphics and animation capabilities to generate an ever-changing video pattern like a growing city.
  • Likes the Sinclair ZX80
    Letter to the editor: reader takes exception to review in the August 1981 Popular Electronics.
  • Line Renumbering
    This program renumbers the line numbers in any other program in memory.
  • 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.
  • Linsac's Game Programs 1 and 2: A Review
    Reivew of games cassettes from Linsac. Games include Three Towers (Towers of Hanoi), Guess a Number, Mastermind, Sketcher (simple drawing program), Hurkle, Nim, Symbol Simon, Nine Lives, The Maze Game, Plain Sailing, Noughts and Crosses, Chinese Puzzle, Tower of Hanoi and Battleships.
  • LJH's Keyboard
    Ad says “wired keyboard hooks up in minutes,” but this project may take beginners 1-2 hours.
  • Looking inside the ZX80
    Basic routines to show the ROM contents.
  • 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
  • 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
  • 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.
  • Machine Code Keyboard Scanning Program
    Machine code routine to decode the keyboard and a Basic program for entering/saving machine code programs.
  • Machine Code Monitor
    Utility program enables you to edit and execute hex Z80 machine code.
  • 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.
  • Machine Code Programming - Multiplication and Division
    Multiplication and division require more thought and attention to detail.
  • 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.
  • Machine Compatibility
    A beginner wrote to ask: All of the following computers have the designation 80 — ZX80, Z80, Z80A, TRS-80. Are programs or software usable between each of these computers? Also there is a Z80 Softcard to apply Z80 programs to the Apple II. Is it reversible?
  • Machine Language Programming - Logical Functions
    Differences between 4K and 8K ROMs can be overcome with machine language.
  • Machine Language Programming Made Simple
    Review of Machine Language Programming Made Simple for your Sinclair ZX80 and ZX81.
  • Machine Language Programming Made Simple for Your Sinclair ZX80 and ZX81
  • Machine language simplified
    Review of Machine Language Made Simple For Your Sinclair ZX80 and ZX81.
  • Machine Language Teaches the ZX80 to READ
    Simulate the READ command with machine language routine.
  • Machine Language Teaches the ZX80 to READ
    In Part 1 (SYNC 1:5) we saw what a READ statement is, how it functions, how to run a machine language subprogram with the USR function, and how to get your machine code into memory with Basic loader program. In this part I will give you the machine language READ subroutine, present a few tips
  • Mail Order Big Keyboard
    Keyboard available from Southern California Optical.
  • Make-Do Connectors
    At SYNTAX we use a Radio Shack connector. Their solderless edge-card, 40-pin connector (#276-1558) usually picks up all the contacts we need. We also use 40- conductor, insulation displacement, ribbon cable and mount the connector with a metal-jawed vise.
  • Making Music with the ZX80
  • Manipulating Strings
    Routines broaden your ability to use strings in interesting ways.
  • 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.
  • Mastermind
    This game is played much like the original board version. The computer selects a code of four colors from a possible six: red. orange, yellow, green, blue, and white (duplicates allowed). It is now up to you to find, in nine moves or less, the exact color and position of each element of the code
  • Mastermind
    Number guessing game.
  • Matrix Drawing
    Draws characters on a 13×20 matrix.
  • Maze Options
    Otis Imboden’s 2-line Maze-O-Graphics inspired several readers. Here are their 4K ROM maze improvements , offering different methods.
  • Mazo-O-Graphix
    Short program to create a maze.
  • MC Programming #11: Storing MC Subroutines in REM
    While you can store machine code subroutines anywhere in your BASIC program, the best place is 1 REM (& 2 REM, if you have two subroutines) .
  • 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.
  • 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
  • Memory Display
    The Memoir Display Program presents 16 bytes of memory in binary, octal, decimal, and character. You can enter a one to four-digit hexadecimal starting address, or hit NEWLINE, if you want to continue without a new entry.
  • Memory Expansion for the ZX-80
    Upgrading the ZX-80 to 16K with a Jade Computer Products MEM-16151K S100 board. The memory board uses 2114-type static RAM instead of the dynamic RAM found in the Sinclair upgrade.
  • Memory Window
    Display 16 consecutive bytes of memory in hex, decimal and character format.
  • Memotech 64K Memopak
    The Memopak is undoubtedly the ultimate memory expansion for the Sinclair. Try DIM A(9500)!
  • Micro Industry in U.K. Shows Stiff Upper Lip
    Clive Sinclair appeared at the third Personal Computer World show, held in September 1980, demonstrating the ZX80 personal computer. Sinclair claimed that his micro was outselling all other combined in the U.K., with total sales to date of 17,000 units. Exports are expected to reach 70% in the next six months.Sinclair had launched the 8K
  • Micro Invaders
    In Galaxy Invaders, you are under attack by a fleet of enemy spacecraft which you must destroy before they destroy you.
  • Micro Juice
    Owners of the Sinclair ZX80 and MicroAce rapidly discover that interruptions of power can cause headaches, not to mention the necessity for re-keying programs.
  • MicroAce-ZX80 Component Equivalence
    Chart showing part numbers and designations between the two computers.
  • Microcommander Interface
    Interface Technology has resumed plans to adapt the TRS-80 Microcommander to the ZX80. The device gives the computer direct control of up to 256 lights and appliances.
  • Mini-Billboard
    Program to print an eight character string on two rather large lines to create a “Mini-Billboard” on the TV screen.
  • ML Scroll Routine
    In 1K ZX80s, large programs easily overfill the 24 available screen lines. This machine language routine deletes the top line from the screen so you can add lines to the bottom.
  • Modifying Hex Monitor for 4K
    Hex Monitor (May 81) stores ML programs without shielding them from BASIC. These changes load ML to reserved space.
  • More Hardware Hints
    Polish the board edge contacts for the RAM almost to bare copper. Otherwise grit gets in the solder and causes intermittent contact.
  • More Truth in Programming
    As long as an expression produces only logical values (0 or -1), you can safely use NOT. Expressions such as IF NOT (A = B) THEN GO TO 10 or IF NOT (X 5 AND Y 8) THEN GO TO 10 are fine. They only deal with logical operators. The value inside the parentheses will
  • Motorcycle Race Game
    Test your skill and luck on a ZX80 motorcycle! In this game you compete with another rider on a 32 mile track on which you meet various obstacles and road conditions. The key to winning the race is meeting the obstacles with just the right speed.
  • Multi-Dimensional Arrays for the ZX80
    Techniques for simulating multi-dimensional arrays on the ZX80.
  • Multiplication Exercise
    This program asks for the multiplier (any number up to 3276) and then presents 5 problems, randomly choosing a number from 1 to 10. You get two tries to answer correctly. After the second try, the machine gives you the right answer with the next problem. At the end, it displays the number correct and
  • Multiplication Three-in-a-Row
    “Multiplication Three-in-a Row” is based on the program “Multiplication Bingo,” by Jean Wilson, Special Education teacher at Leadville High School, Leadville, Colorado. She was seeking a way to motivate students who were having difficulty learning to multiply and found that completing five in a row on a Bingo board helped supply the motivation. An array
  • Multipurpose Memory Expansion
    SABRE Systems has developed a multipurpose memory expansion board to use in a variety of RAM/EPROM combinations.
  • Need fast ZX80/ZX81 service?
    Service firm repaired partially-assembled ZX81.
  • New 8K ROM Features
    Updated list of the redesigned 8K ROM features not available on the 4K ROM and a brief explanation of their functions.
  • New 8K ROM Plus Printer
    Sinclair is revamping the ROM. The new chip will support the low cost printer Sinclair plans to introduce next year.
  • New Consumer Computers Premiere at CES
    The new Sinclair ZX80 is a Z-80 based computer that will sell for $199.95. Initially, the ZX80 will be available only though mail order, directly from Sinclair Research Ltd. A Basic interpreter is contained in an 8K [sic] ROM; RAM can expand up to 16K; and interfaces for printers, disk and cassette storage will be
  • New Magazine
    Announcement of Creative Computing’s SYNC magazine.
  • New Modem
    MicroPeripheral Corp. will introduce a modem for ZX80 and MicroAce machines by 1 January 1981, enabling you to connect to other computers by telephone.
  • New Peripherals from Sinclair
    Printer, flat screen display and 8K ROM. Clive Sinclair has withdrawn the 8K Basic ROM chip for the ZX-80 until the first quarter of 1981. This occurred only a month after it was announced to the world (September 11, 1980). He denies rumors that software bugs are the cause and blames the delay instead on
  • New Product Updates
    Updates on the 8K ROM; printer.
  • New Product Updates (Syntax v2 n1)
    Prestodigitizer requires 8K ROM; Cognivox requires 16K RAM; MicroPeripheral modem held up.
  • New Products Directory: Invasion game
  • New Products for the Sinclair ZX-80
    Two new products for the ZX-80 are now available. A drop-in ROM replacement gives users an 8K extended BASIC, while a 16K expansion module increases the ZX-80’s memory capacity.
  • 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.
  • New view on the world: Pioneer designs 3-D camera lenses with micro
    If the 3-D camera and viewing system invented by [Eric] Howlett really catches on, it will be due in part to … Sinclair ZX80. [The] 3-D lenses could not have been designed and perfected without the use of the calculators and computers — at least not by Howlett. “My nemesis in school always was making
  • New ZX80 ROM and RAM Soon
    Product announcement for 8K ROM for ZX80 and 16K RAM expansion modules.
  • News From MicroAce
    MicroAce and ZX80 owners who want the flicker-free feature of the ZX81 can get it with an add-on board from MicroAce. The board contains only 6-7 chips and solders onto your PC board. The cover fits over the machine with the board installed, although the fit is a little tight on a ZX80.
  • Newsletter for the Sinclair ZX80 Microcomputer
    Announcement for Syntax ZX80.
  • Nicomacus
    Program determines number you are thinking of (between 1 and 100) by successively dividing it by 3, 5, and 7.
  • Nine Defenders Against the Aliens
    Review of Quicksilva’s Defender.
  • Note on copyright; REM skips next line
    REM statements with copyright notices do constitute legal protection; a blank REM causes the interpreter to skip next line.
  • Notes on the ZX80 Display File
    Brook Mick’s letter (Oct. 81) recalls our early experience with our ZX80. We tried the exercise in the manual, p.24. In the 15th line, every character typed made another disappear from the screen! The answer appeared in an article by David Tebbit, reprinted in Sync.
  • 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
  • On-line computers in psychology: The last 10 years, the next 10 years—The challenge and the promise
    1980 marks the 10th anniversary of the National Conference on the Use of On-Line Computers in Psychology. There have been dramatic changes in the applications of computers to psychology during that time, with even more dramatic developments in theory and methodology. Current advances in distributed processing and the rapid dissemination of inexpensive microprocessors portends even
  • Out Front to Stay
    Prediction of staying power of Sinclair ZX80.
  • PEEK, POKE & CHR$ for Beginners (4K)
    Explanation of the commands and functions.
  • Perceptions
    SYNCSUM is a method of checking whether you have entered the program correctly. If you are submitting an article, we ask you to include the SYNCSUM at the end of any program listing.
  • Perceptions
    A ROM Munching Session; Video Sync Signals; Video Modulator Drive Circuitry; Loading.
  • Perceptions
    Conversions: 4K ROM to 8K ROM and 8K ROM to 4K ROM
  • Perceptions
    4K and 8K ROM Command Conversions
  • 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.
  • Perceptions
    The ZX81 Parser and User-Defined Commands; More on the 16K RAM Pack Schematic; Addenda to “The ZX80/81 Video Display System.”
  • Phone Dialer
    Circuit and program to turn the ZX80 into a phone dialer (mechanical).
  • 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.
  • Placing USR Calls in 4K, 8K
    Differences between both ROMs and machine code locations.
  • Plotting with 4K Basic
    If you have only 1K of RAM, this program provides you with a field of 10 lines by 7 columns for plotting. Pixel graphics provide 280 plotting positions: the field is 20 pixels high by 14 pixels wide.
  • POKEing on the ZX80
  • Popular Electronics Tests: The Sinclair Research ZX80 Personal Computer
  • Pounds and Pence, Dollars and Cents
    Programs for working with decimals in 4K ROM.
  • Prime Numbers
    Program lists all prime numbers between 1 and 1000.
  • Product Preview
    Mentions CAI Instruments devices, graphics device from Innovision, speech recognition unit from Voicetek and Sinclair 8K ROM and 16K RAM pack.
  • Program Improvements
    Corrections to 8K Digital Clock, Hexadecimal Math and 4K Blackjack.
  • Programmable Moving Display
    At last you can know the secret of true flicker-free continuous display through software! If you’re a 4K ROM user envying the ZX81’s continuous display, envy no more. For about $10 you can code a rock-steady, moving display into your 4K ZX80.
  • Programmed Responses - Latin Roots
    Drill for students of Latin and Greek.
  • Publisher's Remarks
    Brief mention of the Sinclair ZX-80. Shipping 8,000 units in eight months in the UK; system shown at CES in Chicago in June 1980.
  • 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.
  • Random Functions in 4K, 8K
    Compare RND (4K, 8K), RAND (8K), and RANDOMISE (4K) .
  • Random Ramblings: The British Scene
    Round up of British computers including a brief bit about the ZX80.
  • Random Ramblings: The Consumer Electronics Show
    1979 summer CES; ZX80 mentioned.
  • Reader's Report on MicroAce Video
    Not for neophytes– that’ s John Strain’s assessment of the MicroAce Flicker-Free Video Add-on Board. According to John, “The flicker-free mod circuit board does not physically fit inside the ZX80 case. The components supplied completely prevented mounting the circuit board inside the ZX80.” Also, you can’t use the top display line; you must add components
  • Reading Machine Code Assembly
    Beginning machine language (ML) programmers sometimes have trouble deciphering all the numbers that make up an assembly listing.
  • Recreational Mathematics on the ZX-80
  • Redesigned Telephone Dialer
    Revisions to the telephone dialer available from a reader
  • Reduce 4K Loading Noise
    4K ROM users: instead of building our Cassette Eavesdropper (Dec. 80) to reduce loading noise, try a dual mini-plug from Radio Shack.
  • Reference Card for the ZX80, ZX81 and Timex Sinclair 1000
    Copy of the Nanos reference card.
  • REM Statements
    REM statements can be useful tools for beginning programmers, REM stands for REMark. You can also think of it as REMinder or REMember. The computer does not execute REM statements. It will ignore anything you write after REM in any line. Use REM to write notes to yourself about the functions of various parts of
  • Repeat Key Option
    A repeat key option is relatively simple to build and install.
  • Resources for the ZX-80 and MicroAce (Sync v1 n1)
    Currently available hardware, software, books and user groups and newsleters.
  • Resources for the ZX80 and MicroAce (Sync v1 n2)
    Companies and organizations with products related to the ZX80.
  • Resources for the ZX80 and MicroAce (Sync v1 n3)
    Entries from manufacturers and readers. Includes the name of the item, a brief description, price and complete data on how to obtain it.
  • 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.
  • Reverse Video for ZX80
    Letter to the editor describing a reverse-video circuit for the ZX80.
  • Review: ZX80 Pocket Book
  • Review: ZX80 Programs
  • Robot Composer
    As Richard Forsen has noted, a series of tones can be generated by a series of FOR-NEXT loops. However, we are not accustomed to hearing this pitch scale of tones, and the duration of the tones varies inversely with the pitch. The Robot Composer corrects these deficiencies in this pitch scale and generates rhythmic, melodic
  • ROM List Delay
    4K ROM assembly listing has been delayed for a couple of weeks.
  • 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
  • Schematic of Sinclair 16K RAM Pack
  • Screen Scrolling
    This article shows how a routine can he written and entered into a ZX80 that enables the user to SCROLL the display. In the 4K monitor there is no facility at all for doing other than printing to the last line of the display, and then, when the display is full, the program will stop
  • Season's Greetings
    Here is our personalized holiday greeting to you, courtesy of your ZX80 or MicroAce. With a little clever substitution in lines 450- 640, you can adapt this listing to produce your own video Christmas card.
  • Self-Contained Experimental Robot
    Product announcement for the RMP 2000 robot motion platform, controlled by an on-board ZX80, ZX81, or Timex/Sinclair 1000. Made by Bingel Electronics.
  • Setting Up Bar Charts
    This program listed works with 1K to chart two years of monthly checking account balances with vertical bars. The graph is set up for a range of $0 to $1500, but can be modified for other ranges with a few changes and some trial-and-error experimentation.
  • Setting Up Bar Charts
    This program listed works with 1K to chart two years of monthly checking account balances with vertical bars. The graph is set up for a range of $0 to $1500, but can be modified for other ranges with a few changes and some trial-and-error experimentation.
  • Simulate READ, DATA for Strings
    Although your ZX80 (both ROMs) or ZX81 does not have READ, DATA or RESTORE functions, you can easily mimic them with other functions.
  • Sinclair 8K ROM Software
    Sinclair now offers cassette programs for the ZX80 and ZX81 with 8K ROM.
  • Sinclair News - ROMs and RAMs Here
    By the time you read this, Sinclair will have delivered all 8K ROMs and 16K RAMs on order, according to Nigel Searle of Sinclair.
  • Sinclair Newsletter
    Announcement of Syntax ZX80.
  • Sinclair Research of U.K. to Unveil A Microcomputer: Weighing Less Than a Pound, It Will Cost $200 in U.S., Will Be Marketed Soon
  • 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 Shipments Pick Up
    Sinclair caught up with their ZX80 shipping schedule in November because production rates are up to meet the demand.
  • Sinclair to Replace Faulty 8K ROMs
    A new ROM supplier produced 8K ROMs with a bug, and Sinclair has stopped shipping until a supply of perfect ROMs arrives.
  • 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
    Review of the ZX80.
  • Sinclair ZX80
    Sinclair Research set out to build a simple to use personal computer running Basic and capable of breaking the psychological price barrier of $200. Well, they succeeded with their ZX80. Why ZX80? No reason really except that it’s based on an NEC copy of the Z80 processor chip . . . and it sounds nice.
  • 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's 10-page technical manual ...
    Sinclair’s 10-page technical manual has materialized as a 4-page manual with ZX80 schematic.
  • Sinclair's ZX80: Review of a Very, Very Small Computer
  • Sine Functions on 4K
    Closely approximate sine functions on your 4K ROM with a few BASIC statements.
  • SLOW Motion
    Review of Video Upgrade Board Kit from Computer Engineering Services. Board adds SLOW mode to ZX80 or MicroAce with 8K ROM.
  • Soft Centered
    Software announcements. “The first American software for the Sinclair ZX 80 should be hitting the market soon, courtesy of Image.”
  • Softly, softly
    David Kelly talks to Sue Currier, President of the US software house, SoftSync. SoftSync is one of only several companies in America independently producing and marketing software for the Timex/Sinclair machines – material referred to in the US as third-party software. Like so many companies thriving in the home computer boom, SoftSync came into being
  • SoftSync Software
    Softsync offers ZX80 Invasion.
  • Software Catalogs Available
    Software catalogs for ZX80 and MicroAce owners available from Image Computer Products.
  • Software Received
    Software received by Byte during the prior month. Super Z, extended BASIC commands for the Sinclair ZX-80 and ZX-80 Home Computer Package, both by Lamo-Lem, are mentioned.
  • Software Received
    Bon Mot (Luther Gotwald, Jr.), Musical Scales (Rave Research), Schedi-Mort (E. Arthur Brown) listed.
  • Software Review: And the Walls Came Tumbling Down
    After the successful introduction of Super ZX80 Invasion, Softsync has come out with Double Breakout, its second active display game. Double Breakout is just as much fun as Super ZX80 Invasion, and even more challenging. This, too, fits into 1K of memory.
  • Software Review: Unfriendly Skies
    Softsync’s Super ZX80 Invasion. Using an active display to produce true animation. The tape comes with both 1K and 2K versions of the game.
  • Software Review: ZX Galaxians
    Review of the Artic Computing program.
  • Son of Big Characters
    Print 4x size characters.
  • Space Warp - A Graphics Space Game
    The objective of Space Warp is to reach your base before running out of fuel. In order to do this, you must think ahead and consider how your speed will affect your fuel consumption.
  • Star Count
    After each complete scan of the star field, you must make an estimate of the total number of stars visible on the view screen.
  • State of Microcomputing: Some Horses Running Neck and Neck
    Sinclair has an estimated gross $18m in revenues for 1981. The number of computers in place as of 7/1/81 is 20,000 or more (ZX80).
  • Storing 3-Letter Words in an Array
    I wanted to develop a method of storing as many three-letter words as possible in my 1K ZX80). using as little memory as possible. The solution is based on the fact that charaeter numbers of the letters can be compounded into a single number, which can be stored in an array element. Thus three letters
  • Subroutines -- Super Step-Savers
    Subroutines are mini-programs; they execute a series of steps apart from the main program. In essence, you tell the computer, “Go do those steps and then come back here and proceed with the main program.” The ZX80 remembers where it was and returns to the following line after executing the subroutine. You can call the
  • Super ZX80 Invasion
    This game creates impressive continuous graphics on the ZX80, but limited memory imposes severe limitations on convenient play.
  • 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.
  • Sync Notes
    The Second ZX Microfair Report
  • Syntactic Sums
    Checksum program for programs in Syntax.
  • Syntax Error
    Two errors in Machine Code Print Routine.
  • Syntax Error
    Corrections to ZX80 Checkbook; Improving Display.
  • Syntax Error
    Joe Chaiet’s Bar Chart program contained an error.
  • Syntax Error
    Correction to 4K Phone Number Word Generator.
  • Syntax Errors
    Corrections to Loan Amortization and 30 Programs for the Sinclair ZX80.
  • Syntax Errors
    Errors with Martin Iron’s line renumbering program.
  • TAB Subroutine
    Short subroutine to simulate the TAB function.
  • Talk to Your ZX80
    Cognivox, produced by Voicetek of Goleta, CA, is a speech I/O peripheral for personal computers . It uses both speech recognition and vocal response, so you and your ZX80 can talk to each other. Cognivox maintains a vocabulary of up to 32 words or short phrases (requiring less than 3 seconds of speech time) and
  • 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.
  • 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.
  • The Amazing Active Display and Breakout
    Review of a utility program and game.
  • The Beginner Learns to Load
    Trials and tribulations of loading.
  • The Expandable ZX80 and ZX81
    Author offers seven documented projects and several ideas for additional projects.
  • The Exploding Bookshelf
    Books published about SincIair/MicroAce computers.
  • 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
  • The Hand-Held Computer
    Editorial about handheld and small computers. Sinclair ZX80 is mentioned.
  • The Hidden Chessmen
    The Hidden Chessmen is a search and find game like Hurkle. A knight, a bishop, and a rook are hidden on a chessboard by the computer. You begin the play by guessing a square on the chessboard. The computer tells you if you have found a chess piece and/or what pieces are attacking the square.
  • The History of QZX
    History of the ham radio focused computing magazine founded by Martin Irons.
  • The Home Computer Market, the ZX80 and the Future
    Excerpts of a speech given to the Amateur Computer Group of New Jersey, December 11, 1980.
  • The Math Program
    Program that presented tailored study, using ZX80s, to those who want extra help in math.
  • 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.
  • 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
  • The Sinclair Research ZX80
    The new ZX80 microcomputer from Sinclair Research Ltd is a remarkable device. Although first announce to the North American public in February, 1980, the microcomputer did not become available until the fall.
  • The Sinclair ZX-80 Microcomputer
    Review of the ZX-80.
  • The SYNC Challenge
    Winners of the challenge printed in the first issue.
  • The SYNC Challenge: Hammurabi
    Challenge to readers to get Hammurabi from Creative Computing’s Basic Computer Games converted to work on the 1K ZX-80.
  • The TL$ Function
    Do not overlook the use of the TL$ function when you are creating programs. It is a very useful item. This function allows the ZX80 user to process a string in much the same way that other computers READ DATA statements.
  • The ZX-80 Versus the ZX-81
    Incompatibilities between the ZX-80 8K ROM and the ZX-81.
  • The ZX80 and ZX81 in the USA
    Background about Sinclair Research Ltd., its entry into the United States marketplace, and its first two computers.
  • The ZX80 as a Cipher Machine
    Implementation of the Vigenere cipher.
  • The ZX80 Companion
    Review of the book published by LINSAC.
  • The ZX80 Companion - A Review
  • The ZX80 Keyboard
    Technical description of the keyboard, schematic of the associated circuitry and machine language code for accessing the keyboard.
  • The ZX80 Keyboard
  • The ZX80 Magic Book - A Review
  • The ZX80 Makes the Grade
    In this article we present two programs running on the 1K Basic machine. The first determines the test scores and keeps track of which question caused the class the greatest difficulty. The second finds the class distribution of grades, enabling the teacher to scale the grades.
  • 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.
  • Tic Tac Toe or Noughts and Crosses
    On a computer with a very limited amount of memory (1K) even a simple game like Tic Tac Toe might be a problem to fit. This version of the well known game is short and simple, anyone will be able to understand it.
  • Timex Publication Index, part 1
  • Timex Publication Index, part 2
  • Timex Publication Index, part 3
  • Timex Publication Index, part 4
  • Tioga Toads
    In the following program, three of these toads hop across the screen and announce their order of arrival at the finish line. When all of the toads have finished, the race results are printed on a scoreboard making lavish use of inverse characters.
  • TR$ and LET A$=A$+B$ on the ZX80
    String handling on the ZX80 is reasonably good. The 4K Integer Basic lets the user print, input, and compare strings. and do specialized routines that will transform numbers into strings or characters. Sinclair’s Integer Basic has no string concatenation commands at all. The first will truncate a string from the right side, the second will
  • Translating BASICs -- What Won't Work
    With all the software available for other computers, many ZX80 owners want to convert programs from Microsoft BASIC (used in PETs, Apples, and TRS-80s) to ZX80 BASIC. Sometimes this proves futile due to inconsistencies between Microsoft and ZX80 BASIC.
  • Translating From Other Basics
    Translating ON … GOTO and LEN() to 4K BASIC.
  • Truth in Programming
    It’s time for a little truth in programming, time for a bit of logic. Why let your programs slave away with boring numbers when they can deal with such fascinating concepts as truth and falsity? The logical capabilities of the Sinclair represent one of the best ways to shorten and speed up programs. Many programers
  • Try This
    Two line program.
  • Try This
  • Try This
  • 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.
  • 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.
  • 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.
  • Try This
  • Try This
  • Try This
  • Two Challenges of Taxman
    The computer will lay out the integers from 1 to a maximum which you have entered. You pick one of these numbers; Taxman gets all the remaining factors of that number. If there are no remaining factors of the number chosen, you cannot have it. When there are no remaining factors of any unchosen number,
  • Two Problem-Solving Circuits: Preregulator and Battery Backup
    Add a voltage regulator to your Sinclair power supply; build a batter backup unit.
  • 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.
  • U.K. Firm Bringing Out Small, Low-Priced Microcomputer
    A British electronics company, Sinclair Research, said it is bringing out a microcomputer that measures nine inches by seven inches by two inches thick at its maximum and weighs less than a pound. More important for many computer addicts, will be the machine’s price of about $220 in the U.S., where it will be marketed
  • Understanding Floating-point Arithmetic: Part 1
    The aim of this article is to give the reader some insight into the complex world of floating-point arithmetic. Since the 4K ROM provided only integer arithmetic, readers who possess only this ROM will be unable to try the programs. Nevertheless they will be able to follow the text.
  • Upper and Lower Case Printing
    Uses a copy of the PRINT routine from ROM and lower case character set from the TS 2068 to print in mixed case.
  • Using Extra Keys on Big Keyboard
    Additional logic to implement shifted keys.
  • Using Key and Token Expressions
    Keywords as well as tokens could be typed into program lines in full — spaces and all— with practically a single keystroke.
  • Using Key and Token Expressions
    Keywords as well as tokens could be typed into program lines in full — spaces and all— with practically a single keystroke.
  • Using the Byte-Back Modem
    The Byte-Back modem is a fine device. It works well and actually does more than advertised. The instruction manual, on the other hand, in its attempt to furnish operating instructions, assembly instructions, and engineering data, is a bit sketchy. A description of the non-standard output on the RS232 board is not given nor is there
  • Variable Conversions in the ZX80
    There are many cases when it is convenient to convert one type of variable to another, such as numeric to string, or string to numeric. In the ZX80 variable conversions from numeric to string are done with the STR$() function. The reverse conversion is not available with the 4K Basic. Given a string variable containing
  • Video Display Notes
    Article describes the gut workings of the MicroAce/ZX80 video display.
  • Video Modifications for the ZX80
    Inverted and direct video.
  • Video Modifications for the ZX80
  • Video Upgrade Kits for ZX80 in US Again
    Once again ZX80 and MicroAce owners can enjoy the flicker-free qualities of ZX81/TS1000s
  • What Can You Buy for Under $1000?
    A Sinclair ZX80, obviously.
  • What's So Difficult About ZX-80 Machine Code?
    Even inexperienced users unfamiliar with the ZX-80’s inner workings can program — in Zilog Z-80
  • What's The Difference
    Differences between ZX-80, ZX-81 and T/S 1000.
  • Widget
    Widget is a relative of the games Hammurabi and Lemonade Stand, in which the player allocates his resources for the best effect. As the player, you are the head of the United Widget Company, trying to expand your business as rapidly as possible without going broke.
  • World's Lowest-Priced Computer
    The world’s least expensive computer is the Sinclair ZX-80. Selling at a retail price of $199.50, and released in January, 1980, it has helped Sinclair Research Limited emerge as the third major competitor in the personal-computer industry.
  • Writing Game Programs
    How do you start writing game programs?
  • You May Fire When Ready, Gridley!
    Have you ever wished that you could command a submarine, survey the sea through the periscope to locate the enemy fleet, and give the orders to fire your torpedos at the target ship? Well, now thanks to the ZX80 and the Torpedo Alley program from Zeta Software you ean do just that, and for very
  • ZX 80-81 Programs
    Four programs: trigonometric Fourier synthesis, program labels, dodge game, rapid descent.
  • 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.
  • ZX-80 Schematic
  • ZX/TS Power Supplies
    Table of details about and schematics of the ZX80, ZX81 and TS1000 power supplies.
  • ZX80 and MicroAce Bus Pinout
  • ZX80 Budget
    Can keep track of expenses. As written, program keeps addition totals on 18 accounts.
  • ZX80 Check Book
    Program records up to 10 transactions at a time. Keep them on file by storing the program with the variables intact.
  • ZX80 Double Breakout
    Review of the game from Softsync.
  • ZX80 Games
    A Night in Las Vegas (Slot Machine, Roulette, Blackjack and Craps) from Lamo-Lem.
  • ZX80 Group
    Licensed hams using the Sinclair ZX80 or Microace now have a user net on single sideband. Contact Marty Irons, K2MI, 46 Magic Circle Drive, Goshen, NY 10924.
  • ZX80 Pocketbook
    THE ZX80 P0CKETB00K is now available from SYNTAX.
  • ZX80 Prestel Model
    Model of the British Prestel data base tree structure. It can be used with your own data for display to show how Prestel data is accessed.
  • ZX80 Review
    A complete, ready-to-run computer for under $350 would make anyone sit up and take notice.
  • ZX80 Table
    Constructs number tables with columns lined up.
  • ZX80/Microace Games
    The Chest of Classics comes with four games: Life (Conway’s Game of Life), Lunar Lander, Mindmaster, and K-Trek, a variant of Star Trek. Complete BASIC listings are provided as well as a color keyboard overlay. From Lamo-Lem.
  • ZX80/ZX81 Stock Programs
    Product announcement for programs from M.H. Marks Ent.
  • ZX80/ZX81 Users Club
    The ZX80/ZX81 Users Club in Surrey, England serves all users, beginner to expert.
  • ZX81 Intro
    Subroutine for use at the beginning of user-friendly programs.
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