website/content/museum/icl-personal-computer.md

---
title: ICL Personal computer
categories:
- Computers
types:
- Professional Computer
origins:
- United Kingdom
years:
- '1981'
cpus:
- Intel
params:
  name: Personal computer
  company: /companies/icl
  company_name: ICL
  specs:
  - label: NAME
    value: Personal computer
  - label: MANUFACTURER
    value: ICL
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: United Kingdom
  - label: YEAR
    value: '1981'
  - label: BUILT IN LANGUAGE
    value: None
  - label: KEYBOARD
    value: Full-stroke 102 keys with function keys and numeric keypad
  - label: CPU
    value: Intel or AMD 8085A
  - label: SPEED
    value: 3 MHz
  - label: RAM
    value: 64 KB up to 512 KB
  - label: VRAM
    value: Depending on the video terminal used
  - label: TEXT MODES
    value: 80 characters x 25 lines
  - label: GRAPHIC MODES
    value: None
  - label: COLORS
    value: Monochrome
  - label: SOUND
    value: Beeper
  - label: SIZE / WEIGHT
    value: 50.5(W) x 40.5(D) x 14(H) cm.
  - label: I/O PORTS
    value: 2 x serial ports. Serial printer and keyboard on terminal
  - label: BUILT IN MEDIA
    value: 2 x 5.25'' 256 KB Double sided / Double density FDD
  - label: OS
    value: CP/M or MP/M
  - label: POWER SUPPLY
    value: Built-in power supply
  - label: PRICE
    value: From £1,800
  tabs:
  - photos
  photos:
  - title: COMPLETE SYSTEM
    subtitle: ''
    text: Complete running system with an ICL dot matrix printer, actually an Oki Microline 82, and a Maplin 300 baud modem.
    image: null
  - title: BACK
    subtitle: ''
    text: |-
      **(1)** Keyboard connector\
      **(2)** Parallel printer DB25 connector\
      **(3)** Host/serial DB25 connector\
      **(4)** 2 x serial port. The upper one is dedicated to the video terminal
    image: null
  - title: INSIDE SYSTEM
    subtitle: ''
    text: |-
      **(1)** The backplane features 8 connectors and uses a specific RAIR format\
      **(2)** Serial board\
      **(3)** 64 KB memory board. Uses 32 x 4116 RAM chips\
      **(4)** Processor board\
      **(5)** Floppy disk controller board\
      **(6)** Switching power supply unit and large fan\
      **(7)** 2 x 5.25" Tandon FDD. Double side, double density, 48TPI, 780 KB models.
    image: null
  - title: INSIDE VIDEO TERMINAL
    subtitle: ''
    text: The video terminal features a complete computer board including a 8085 processor, ROM an RAM memory, and programmable I/O ports.
    image: null
  comments:
  - author: Steve Johnson (USA)
    date: Wednesday 9th March 2011
    text: I used to work as a test engineer in the ICL plant in Kidsgrove where these machines were made. I automated the test suite by utilising the 25th line of the screen which you could both write to and read from. This enabled the machine to know where it was up to after a reboot say after formatting the Hard Disc. This greatly reduced the number of manual interventions required to test the machine and earned me an award from the ICL Suggestion Awards Scheme.
  - author: Ruben Hillier
    date: Monday 6th September 2021
    text: 'I have the icl model 31 but it doesn''''t work I was hoping someone would be able to help. It''''s been in a attic for a long time got it down to try it all iy dose is show ":" on the screen. It did power up once and had some righting then "A: " But froze and touching keyboard did nothing but beep. I put an ms dos fopy in nothing happened.'
  - author: Jim Hancock (UK)
    date: Wednesday 10th March 2021
    text: In about 1982, I was working in the Magnetic Tape Group, part of “Peripheral Product Engineering� in ICL Kidsgrove. The department received a “Robbogram�, demanding a £100 terminal for this machine. Robbograms were terse messages from Rob Wilmott, so rather like a command from God! Somehow this requirement ended up with George Fitzgerald, my manager, and it ended up in my lap. I had NO idea about terminals, keyboards, RS232 etc, so it was a steep learning curve. I first played with an ADM3A terminal, a very basic machine, almost a glass teletype, Not really up to the job, and costing well over £200. Fortunately someone in our commercial department contacted Nissei Sangyo, who represented (amongst many other manufacturers) Kokusai Electric, a terminal manufacturer based not far from Tokyo. They were developing a new range of terminals, and we had 3 prototypes, KDS7361, KDS7362 and KDS7363. KDS7362 had the right balance of features, and we validated it using a Rair Black
      Box. When ICL wanted to launch the Personal Computer, the tooling wasn’t ready for injection moulded cases, George Fitzgerald and I persuaded Kokusai to make 250 machines with vacuum moulded cases. They weren’t happy, but George could be very persuasive. Real typists found that the 2-key lockout keyboard slowed them down, and some Wordstar issues led to a “release 2� product, with n-key rollover keyboard and a specific Wordstar mode which prevented characters disappearing if you typed too fast. I got two (exhausting) trips to Japan out of this project. I remember bringing a release 2 product back as hand luggage, only to find at Heathrow I couldn’t raise the import duty, and had to phone a friend! It was a very successful product, an OEM sales group selling it was formed, and later colour terminals were introduced, but by this time I was back in my comfort zone, introducing 1/4 inch and 1/2 inch cartridge tape drives. Jim Hancock
  - author: Stephen Dewey (United Kingdom)
    date: Friday 13rd October 2017
    text: The technical authors at BRA01 were very keen on using the game that was started with the command Advent.something to "learn" about the RAIR $)
  - author: Murray (New Zealand )
    date: Saturday 25th June 2016
    text: |-
      Hello I have a ICL 8120/01 with 6 xtra cards and all the original ICL software,cp/m disks, ICL PC10 ,,,murraykellyjacob@gmail.com\
      Would like to know what the /01 means in 8120/01 ,,
  - author: Jon Hales (UK)
    date: Sunday 12th October 2014
    text: I have an ICL 8122/05 (Rair Black Box) with 8088 and a 10Mb Rodime Hard Disk, but haven''t tried to switch it on. Having removed all components, I powered on PSU alone which looks OK, but it''s providing only 10.3 volt instead of 12.0 volt. The HD has several labels referring to maintenance replacement of transistors, so under-volting PSU might be deliberate. Any info or software much appreciated.
  - author: Ian White (uk)
    date: Thursday 7th November 2013
    text: I designed and manufactured the first 3000-4000 power supplies for this machine. The main feature of this power supply was that it was one of the first designs to use the new power MOSFET transistors that switched at high frequency and reduced the size and weight of the power supply.
  - author: Peter Roberts (Manchester, England)
    date: Sunday 24th February 2013
    text: I have an ICL Personal Computer, Catalogue Serial No - 8120/01, can anyone give me any info on this machine as I''m struggling to find anything about it.
  - author: Ian Lever (UK)
    date: Tuesday 19th February 2013
    text: |-
      I used to write instructions for modifying the ICL PC2 for re-sale as BT machines$ the ICL badges were literally prised off, and lovely new brown BT M22xx badges stuck on in their place!

      I provided final line support within BT for the M2200 series - interfacing with ICL, and found ICL great to work with.
  - author: Bill Perry (UK)
    date: Thursday 11th October 2007
    text: The PC2 series were also sold on to British Telecom through BT Merlin for them to resell. They were rebadged as the M2200 series. Having the the same numbers at the end as those shown on the first page. e.g. Model 15 =M2215, Model 26 = M2225 etc.
  oc_id: 752
  source:
    url: https://web.archive.org/web/20230607225818/http://www.old-computers.com/museum/computer.asp?c=752
    date: '2023-06-07'
---

In the early 70s, the British government whished an English computer company could compete with the world major manufacturers. Some years later, the ICL company became one of the larger manufacturer of computers in Europe and did really compete with U.S. companies.

In 1980, before the ICL Personal Computer was born, the company met serious financial problems, the English government paid several million pounds and ICL asked the British RAIR CIE to provide the ICL-PC hardware.

This ICL Personal Computer is thus exactly the same machine as the [RAIR Black Box](/museum/rair-microcomputer-black-box/) system, a backplane 8085 based system using a serial video terminal as video display, and CP/M (single user) or MP/M (multi-user) operating systems.

Two series were released. The **PC1** series is the model pictured here. The **PC2** series was the same design case as the [ICL PC Quattro](/museum/icl-quattro/). This used an Intel or AMD 8085AH-2 CPU at 5MHZ

The model numbers for the PC1 series were:\
**Model 10** (pictured here) - 64 KB RAM, 2 x 5.25" FDD, CP/M O.S.\
**Model 30** with a 5 MB hard disc, CP/M O.S.\
**Model 31** 64 KB RAM, three users, 5 MB hard disc, MP/M O.S.\
**Model 32** 256 KB RAM, three users, 10 MB hard disc, MP/M O.S.

Those of the PC2 series were:\
**Model 15** 64 KB RAM, 2 x 5.25" FDD, CP/M O.S.\
**Model 25** with a 5 MB hard disc, CP/M O.S.\
**Model 26** 64 KB RAM, three users, 5 MB hard disc, MP/M O.S.\
**Model 35** 256 KB RAM, three users, 10 MB hard disc, MP/M O.S.

**Agnus WR Gulliver** reports us:\
There were a few simple games written for it, mostly text based (what do you expect, it uses CP/M), but it's main use was of course as an office machine.\
I recall it being a slow machine to use, even boot-up took about a minute. You had to be very careful with the hard disk because it didn't have auto-parking heads. After it was switched off you had to wait about a minute to switch it on again.

According to **K.-L. Butte**,there were 3 different models of it marking the 3 major development steps: The first incarnation wit 8085 and MP/M, the second with 8088 and Concurrent CP/M and the third with 8086 and Concurrent CP/M.