---
title: Acorn Computer System 1
categories:
- Computers
types:
- Home Computer
origins:
- United Kingdom
years:
- '1979'
cpus:
- '6502'
params:
  name: System 1
  image: /media/museum/photos/acorn_system1_keyboard_2.jpg
  company: /companies/acorn-computer
  company_name: Acorn Computer
  specs:
  - label: NAME
    value: System 1
  - label: MANUFACTURER
    value: Acorn Computer
  - label: TYPE
    value: Home Computer
  - label: ORIGIN
    value: United Kingdom
  - label: YEAR
    value: '1979'
  - label: BUILT IN LANGUAGE
    value: Machine code
  - label: KEYBOARD
    value: Calculator-style hexadecimal keyboard, 25 keys
  - label: CPU
    value: '6502'
  - label: SPEED
    value: 1 Mhz
  - label: RAM
    value: 1 kb
  - label: ROM
    value: 512 bytes
  - label: TEXT MODES
    value: 8 x 1 (8 digits seven-segment LED display)
  - label: GRAPHIC MODES
    value: None
  - label: COLORS
    value: None
  - label: SOUND
    value: None
  - label: I/O PORTS
    value: Eurocard bus (100 x 160 mm cards), Tape interface (300 bauds), RAM I/O (16 lines I/O)
  - label: POWER SUPPLY
    value: External power supply unit (Option, £7)
  - label: PERIPHERALS
    value: Memory expansion boards (4k / 8k), Video card, 4k Basic card, Assembler/desassembler card
  - label: PRICE
    value: |-
      UK: Kit: £75 - Assembled: £91\
      France: Kit : 198 Assembled : 222
  tabs:
  - photos
  - adverts
  - emulators
  - links
  photos:
  - title: THE WHOLE SYSTEM
    subtitle: ''
    text: The two boards are "sandwich" mounted.
    image: /media/museum/photos/acorn_system-1_1.jpg
  - title: UPPER BOARD
    subtitle: ''
    text: This card deals with the keypad and the display.
    image: /media/museum/photos/acorn_system1_keyboard.jpg
  - title: LOWER BOARD
    subtitle: ''
    text: This card is where the 6502, RAM and ROM are mounted. It can be considered the "mainboard".
    image: /media/museum/photos/acorn_system1_mainboard.jpg
  adverts:
  - title: UK ADVERT (DEC. 1979)
    subtitle: ''
    text: Thanks to David Wilson for this picture
    image: /media/museum/pubs/acorn_system1_pub-dec1979.jpg
  - title: UK ADVERT (FEB. 1980)
    subtitle: ''
    text: Thanks to David Wilson for this picture
    image: /media/museum/pubs/acorn_system1_pub-uk_feb1980.jpg
  emulators:
  - title: Acorn Microcomputer Emulator
    url: http://www.cary.demon.co.uk/acorn/acornEmulator.html
    platform: Windows
    text: Nice little emulator written by Mike Cowlishaw
  links:
  - title: The Acorn Microcomputer (1979) page
    url: http://www.cary.demon.co.uk/acorn/
    text: Nice dedicated page with info and emulator!
  comments:
  - author: Achim (USA and Germany)
    date: Sunday 11th December 2022
    text: Hello, please contact me if you have Acorn System 1 (or even System 75, 2, 3, 4 or 5) for sale.I have an address in the US and in Germany.
  oc_id: 483
  source:
    url: https://web.archive.org/web/20230210082452/http://www.old-computers.com/museum/computer.asp?c=483
    date: '2023-02-10'
---

This 6502 modular system was the first computer produced by Acorn in 1979. It was basically the same type of computer as competitors offered at that time ([KIM-1](/museum/mos-technology-kim-1/), [MK14](/museum/sinclair-mk-14/), [Nascom](/museum/lucas-nascom-1/), etc...) : a 6502 or Z80 CPU (in this case, a 6502) mounted on a simple "naked" board, with a one-line display and a hexadecimal keyboard.

The System 1 is no exception : it featured an eight-digit seven-segment LED display, a hexadecimal keyboard (25 keys) and as there was no built-in BASIC in the computer, it had only machine-code.\
Fortunately there was a tape-recorder interface communicating at 300 bauds.

Like all these types of "hobbyist" computers, the main advantage was the expandability of the system. They were quite cheap machines because they were shipped basically "naked". Then you had to buy whatever cards you wanted (video, BASIC, sound, etc...). Here the system was Eurocard compatible, which was a well-known expansion board standard at that time.\
If then you had "too many" expansion cards, a Eurocard rack was available to organise the whole system.

The System 1 itself was composed of two Eurocard boards (one for the CPU and the other for the keypad and display) mounted one above the other (sandwiched, you could say), the two being connected by a ribbon cable.