CHAPTER 1 | Setting up the ZX81 & how to use this manual, whether or not you know BASIC. |
CHAPTER 2 | Telling the computer
what to do How to type things in to the computer ![]() ![]() |
CHAPTER 3 | A History lesson |
CHAPTER 4 | The Sinclair ZX81 as
a pocket calculator Statement: PRINT with commas & semicolons Operations: +, -, *, /, ** Expressions & scientific notation |
CHAPTER 5 | Functions Statement: RAND Functions: ABS, SGN, SIN, COS, TAN, ASN, ACS, ATN, LN, EXP, SQR, INT, PI, RND, FUNCTION |
CHAPTER 6 | Variables Statements: LET, CLEAR Simple numeric variables |
CHAPTER 7 | Strings Operation: + (for strings) Functions: LEN, VALSTR$ Strings, simple string variables |
CHAPTER 8 | Computer programming Statements: RUN, LIST Programs Editing programs using ![]() ![]() |
CHAPTER 9 | More computer programming Statements: GOTO, CONT, INPUT, NEW, REM, PRINT STOP in INPUT data BREAK |
CHAPTER 10 | If... Statements: IF, STOP Operations: =, <, >, <=, >=, <>, AND, OR Function: NOT |
CHAPTER 11 | The character set Functions: CODE, CHR$ The character set is thoroughly non-standard GRAPHICS |
CHAPTER 12 | Looping Statements: FOR, NEXT, TO, STEP |
CHAPTER 13 | SLOW & FAST Statements: SLOW, FAST The ZX81 operates at two speeds: one neat, the other fast. |
CHAPTER 14 | Subroutines Statements: GOSUB, RETURN |
CHAPTER 15 | Making your programs
work Flowcharts & debugging |
CHAPTER 16 | Tape storage Statements: SAVE, LOAD |
CHAPTER 17 | Printing with frills Statements: CLS, SCROLL PRINT items: AT, TAB |
CHAPTER 18 | Graphics Statements: PLOT, UNPLOT |
CHAPTER 19 | Time & motion Statement: PAUSE Function: INKEY$ |
CHAPTER 20 | The ZX81 Printer Statements: LPRINT, LLIST, COPY |
CHAPTER 21 | Substrings Slicing, using TO |
CHAPTER 22 | Arrays Statement: DIM |
CHAPTER 23 | When the computer gets
full Odd things happen |
CHAPTER 24 | Counting on your fingers Binary & hexadecimal counting |
CHAPTER 25 | How the computer works What the individual chips do Statement: POKE Function: PEEK |
CHAPTER 26 | Using machine code Statement: NEW Function: USR |
CHAPTER 27 | Organization of memory |
CHAPTER 28 | System variables |
APPENDICES
A
The character set
B
Report codes
C
The ZX81 for those that understand BASIC
Copyright 1980 Sinclair Research Limited