website/content/museum/feedback-abacus-educational-computer.md

---
title: Feedback ABACUS Educational Computer
categories:
- Computers
types:
- Professional Computer
origins:
- United Kingdom
years:
- '1971'
cpus:
- Circuit module
params:
  name: ABACUS Educational Computer
  image: /media/museum/photos/feedback_ec372_system_2.jpg
  company: /companies/feedback
  company_name: Feedback
  specs:
  - label: NAME
    value: ABACUS Educational Computer
  - label: MANUFACTURER
    value: Feedback
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: United Kingdom
  - label: YEAR
    value: '1971'
  - label: BUILT IN LANGUAGE
    value: None
  - label: KEYBOARD
    value: 36 Input keys and 4 Function keys
  - label: CPU
    value: Circuit module
  - label: SPEED
    value: 250 Hz. (4 ms per instruction except Multiply & Divide
  - label: CO-PROCESSOR
    value: None
  - label: RAM
    value: 1 KB of ferrite core storage organised as 512 off 2-byte (16 bit)
  - label: ROM
    value: No ROM
  - label: TEXT MODES
    value: Hard copy and punched paper tape output via ASR33 Teletype
  - label: SOUND
    value: No sound
  - label: SIZE / WEIGHT
    value: 78.7 (H) x 50.8 (W) x 29.2 (D) cm. / 22.4 Kg
  - label: I/O PORTS
    value: Teletype connector
  - label: BUILT IN MEDIA
    value: Non volatile memory
  - label: POWER SUPPLY
    value: Built-in power supply unit
  - label: PRICE
    value: £1800.
  tabs:
  - photos
  forum_thread: 802
  photos:
  - title: SYSTEM
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_system_1.jpg
  - title: TOP VIEW
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_topview_1.jpg
  - title: IN USE
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_inuse_1.jpg
  - title: DETACHABLE KEYBOARD
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_keyboard_1.jpg
  - title: KEYBOARD CLOSE-UP
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_keyboard_2.jpg
  - title: FRONT PANEL
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_frontpanel_1.jpg
  - title: FRONT PANEL IN USE
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_inuse_2.jpg
  - title: BACK SIDE OPENED
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_backopen_1.jpg
  - title: SYSTEM CARDS
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_backcards_1.jpg
  - title: 1024 BIT CORE MODULE
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_memmodule_1.jpg
  - title: 'CORE MEMORY #1'
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_memmodule_2.jpg
  - title: 'CORE MEMORY #2'
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_memmodule_3.jpg
  - title: 'CORE MEMORY #3'
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec372_memmodule_4.jpg
  - title: EC-362 FRONT PANEL
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec362_frontpanel_1.jpg
  - title: EC-362 KEYBOARD
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_ec362_keyboard_1.jpg
  - title: FULL SYSTEM BACK
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_372-362_backclosed_1.jpg
  - title: FULL SYSTEM - INSIDE
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_372-362_backopen_1.jpg
  - title: FULL SYSTEM - FRONT SIDE
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_372-362_system_1.jpg
  - title: FULL SYSTEM RUNNING
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_372-362_systemon_1.jpg
  - title: FULL SYSTEM - KEYBOARDS
    subtitle: ''
    text: ''
    image: /media/museum/photos/feedback_372-362_keyboards_1.jpg
  oc_id: 821
  source:
    url: https://web.archive.org/web/20230607054056/http://www.old-computers.com/museum/computer.asp?c=821
    date: '2023-06-07'
---

The computer system consisted of two units - **EC362** and **EC372** - that could be used independently or linked together to provide a complete system for computer education.

To enable the input of relatively long programs and the output of computed results, an ASR33 Teletypewriter with 8-hole punched paper tape input and output was connected to the two linked units. In addition, a textual output was printed on an 8 inch (200 mm) wide paper roll.

Unit EC362 was the Arithmetic Unit and unit EC372 was the Core Store and Control Unit. Both units had the same physical size (about 1m high x 600mm wide x 600 mm deep) and the large size allowed the units to be used in a classroom, either singly or jointly, in a demonstration mode.

Each unit had a removable, push button, input console connected to its parent unit via a long connector. This feature allowed input and control of the units at the same time as allowing students a full view of the mimic diagrams on the front of the units.

The lamps on the mimic diagrams could be arranged in groups of either three or four yellow and white lenses. This feature provided the opportunity to use OCTAL coding or HEXADECIMAL coding without having to make wiring changes. The use of different groupings of the coloured push button key tops provided the same facility for input coding.

Behind each of the removable consoles was a set of switches that were used to insert predetermined fault conditions to allow the teaching of faultfinding procedures.

Special thanks to **Brian Townsend** who gave us this venerable machine.