Acorn System 1 User Manual

The Acorn System 1 User's Manual is Acorn Computers' companion to the Acorn System 1 Technical Manual: a course in 6502 machine code written around the System 1's hex keypad and seven-segment display. The hosted scan has 80 PDF pages and no text layer, and most of the body text is set in capitals. Mike Cowlishaw credits Sophie Wilson with writing it.

It is a programming manual. For repairs, the parts lists are in the Acorn System 1 Technical Manual and the circuits in Acorn System 1 Circuit Diagrams. This manual explains what the monitor firmware does and how to drive the machine from the keypad, which is how a repaired board is tested.

Contents

From the manual's contents page:

• Part 1
  • Chapter 1, an introduction to the binary number system: binary numbers, logical manipulations, arithmetic manipulations, binary coded decimal arithmetic
  • Chapter 2, welcome to the machine: how the Acorn microprocessor works; the monitor commands M, up and down; a first program (assembly language, machine language, the LOAD, STORE and JUMP instructions); entering a program and the GO command; JMP and JSR; ORA and EOR; ADC, SEC and CLC
  • Chapter 3, inside the 6502: accumulator, program counter and status register; the stack pointer; the X and Y registers; making the program "friendly"
  • Chapter 4, the remainder of the instruction set: branches, indexing, indirection, read-modify-write instructions, the remaining instructions
  • Chapter 5, Acorn hardware: chip layout and bus; reset, interrupt request and non-maskable interrupt; 6502 internal architecture; PROMs, EPROMs, RAM and RAM/IO; the keyboard and tape interface; power supply
  • Chapter 6, firmware: the tape store and load; the breakpoint and restore command; the single stepping facility; the monitor listing
• Part 2, application programs
• Appendices: A, 64-character ASCII on Acorn's seven-segment display; B, instruction set; C, hexadecimal to decimal conversion table; D, Acorn monitor address information; glossary

What it settles

Chapter 6 prints the listing of the 512-byte monitor, and appendix D gives the monitor's addresses. Appendix A shows how each character looks on the seven-segment display, which helps when the display shows something other than hexadecimal.

What this manual does not contain

• No parts list, component values or circuit diagrams.
• No fault-finding. Chapter 5 explains the hardware but does not diagnose it.

Pages that cite this document

• Acorn System 1

Download: Acorn System 1 User Manual.pdf