ITT 2020 Computer - Apple II Clone

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The ITT 2020 was the first Apple II clone, manufactured by ITT in the UK under license from Apple Computer, specifically for the European market. In the United Kingdom, it was distributed by Microsense Computer Limited. In the Benelux, it was distributed by Bell Telephone mfg. company. The ITT 2020 was released in 1979 but was only manufactured for a few years.

The major difference, and the reason ITT believed this personal computer would be a success, was that the colour video signal conformed to the European PAL standard, rather than the American NTSC standard. This meant colour graphics could be viewed using a standard European monitor or TV set, rather than having to import an NTSC monitor from America or Japan as was the case with the Apple II. 

The most significant other change was the hi-res graphics resolution. ITT increased the horizontal resolution from the 280 pixels the Apple II Plus used, to 360 pixels. The vertical resolution however, remained the same. This made many Apple II programs incompatible with this computer. The higher resolution was a necessary consequence of the higher frequency of the PAL colour subcarrier. In order to provide enough bits to the video shift register to generate the higher PAL subcarrier frequency, 9 bits per memory location were needed, rather than the 7 bits the Apple II+ used. To achieve this, an extra 16Kx1 memory chip was added to the motherboard, which added a 9th bit to the Hires memory pages (0x2000 to 0x5FFF). This made it necessary to modify the graphics routines in Apple's Applesoft Basic interpreter in ROM. To emphasise this difference, ITT called this "PALSOFT". To make room for the longer graphics routines (manipulating the 9th bit required extra code), the HPLOT instruction was limited to a single parameter, rather than a string of parameters.

ITT also supplied a floppy disk drive that was identical to the Apple II disk drive with 13 sectors and DOS 3.2. They never supplied the upgrade to 16 sectors and DOS.

Some brief information regarding the manufacture of the computer was provided to us by Alan Campion in 2016:

'The ITT2020 that's in your collection almost certainly passed through my hands, because at the time I worked for the ITT Consumer Products division at Basildon, where they were assembled, and I was tasked with overseeing that. As well as myself, the team consisted of one test technician, and about 16-20 female assemblers, occupying one small corner of the factory. The rest of the factory was given over to churning out TV's. As well as the UK, some of our production also found its way to Germany.'

Manufacturer: ITT
Date: 1979



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ITT 2020 Computer - Apple II Clone Manuals:

Item Manufacturer Date
Apple Parallel Printer Interface Card Installation and Operating Manual Apple Unknown
Apple II: Supplement to Owners Manual Apple Unknown
Apple II: Monitor II Users Manual Apple Unknown
Integer Basic Manual Apple Unknown
Apple II: DB Master (Digital Download) ???? Unknown
Apple II: Communications Interface Card Installation and Operating Manual Apple Unknown
Apple Parallel Printer Interface Card Installation and Operating Manual Apple 1978
Apple II: Applesoft Basic Programming Reference Manual Apple 1978
Apple II The Applesoft Tutorial Apple 1979
Apple II: Reference Manual Apple 1979
Apple II: Graphics Tablet Operation & Reference Manual Apple 1979
Apple II: Reference Manual Apple 1979
Apple II: DOS 3.2 Do's & Don'ts of DOS Apple 1979
Apple II: The Applesoft Tutorial Apple 1979
Apple Pascal Operating System Reference Manual Apple 1980
Model 7490A GPIB Interface for Apple II Owners Manual California Computer Systems 1980
Apple II: Apple Fortran Language Reference Manual  Apple 1980
Apple II: Apple Pascal Language Reference Manual Apple 1980
Apple II: Apple Pascal Operating System Reference Manual Apple 1980
Apple II Super Serial Card Apple 1981
Apple III: Pascal - Introduction, Filer, and Editor Apple 1981
Apple II: The DOS Manual (DOS 3.3) Apple 1981
Apple II: Apple Language System Installation and Operation Manual Apple 1981
Apple III: Visicalc III User's Manual Apple 1982
Copy II Plus 4.0 Disk Utility System Apple 1982
Apple IIe: Owner's Manual Apple 1982
Apple II: DOS Programmer's Manual Apple 1982
Accelerator II for Apple II and II Plus Saturn Systems 1983
Apple IIe: Owners Manual Apple 1985
GEOS Graphic Environment Operating System Version 2.0 Berkeley Softworks 1986

ITT 2020 Computer - Apple II Clone Articles:

Item Manufacturer Date
Memories - MZ80B - Fond Memories Unknown
Helen Clark (Helen Jackson): Reminiscence Apr 2021
John Page: My time at LEO 2022

Magazines RELATED to ITT 2020 Computer - Apple II Clone in our Library

Item Manufacturer Date
Call-A.P.P.L.E. Extra - All About Pascal Unknown
Popular Electronics - December 1977 Dec 1977
Practical Computing - July/August 1978 ECC Jul 1978
Personal Computer World - August 1978 Aug 1978
Personal Computer World - September 1978 Sep 1978
Personal Computer World - November 1978 Nov 1978
Practical Computing - December 1978 ECC Dec 1978
Practical Computing - April 1979 ECC Apr 1979
Practical Computing - May 1979 ECC May 1979
Personal Computer World - June 1979 Jun 1979
Practical Computing - October 1979 ECC Oct 1979
Practical Computing - December 1979 IPC Electrical Electronic Press Dec 1979
Call-A.P.P.L.E. - Complete 1980 Set 1980
Personal Computer World - March 1980 Mar 1980
Apple Orchard - Vol 1 Number 1 - March/April 1980 Mar 1980
Personal Computer World - July 1980 Jul 1980
Personal Computer World - August 1980 Aug 1980
Computer Age - September 1980 Computer Age Sep 1980
Micro - The 6502 Journal November 1980 Nov 1980
Apple Orchard - Winter 1980 - 1981 Dec 1980
Personal Computer World - January 1981 Jan 1981
Call-A.P.P.L.E. - January 1981 Jan 1981
Call-A.P.P.L.E. - February 1981 Feb 1981
Computer Age - February 1981 Computer Age Feb 1981
Call-A.P.P.L.E. - March/April 1981 Mar 1981
Call-A.P.P.L.E. - May 1981 May 1981
Call-A.P.P.L.E. - June 1981 Jun 1981
Call-A.P.P.L.E. - July/August 1981 Jun 1981
Personal Computer World - July 1981 Jul 1981
Apple Orchard - Vol 2 Number 2 - Summer 1981 Jul 1981
Call-A.P.P.L.E. - September 1981 Sep 1981
Personal Computer World - October 1981 Oct 1981
Call-A.P.P.L.E. - October 1981 Oct 1981
Call-A.P.P.L.E. - November/December 1981 Nov 1981
Call-A.P.P.L.E. - January 1982 Jan 1982
Windfall January 1982 Windfall Jan 1982
Call-A.P.P.L.E. - February 1982 Feb 1982
Call-A.P.P.L.E. - March 1982 Mar 1982
Windfall March 1982 Windfall Mar 1982
Call-A.P.P.L.E. - April 1982 Apr 1982
Personal Computer World - May 1982 May 1982
Call-A.P.P.L.E. - June 1982 Jun 1982
Call-A.P.P.L.E. - July 1982 Jul 1982
Personal Computer World - July 1982 Jul 1982
Call-A.P.P.L.E. - August 1982 Aug 1982
Personal Computer World - November 1982 Nov 1982
Call-A.P.P.L.E. - February 1983 Feb 1983
Windfall March 1983 Windfall Mar 1983
Personal Computer World - March 1983 Mar 1983
Windfall April 1983 Windfall Apr 1983
Practical Computing - June 1983 Jun 1983
Windfall June 1983 Windfall Jun 1983
Windfall June 1983 Windfall Jun 1983
Call-A.P.P.L.E. - June 1983 Jun 1983
Windfall August 1983 Windfall Aug 1983
Call-A.P.P.L.E. - August 1983 Aug 1983
Windfall October 1983 Windfall Oct 1983
Hard Core December 1983 Hard Core Dec 1983
Call-A.P.P.L.E. - December 1983 Dec 1983
Personal Computer World - January 1984 Jan 1984
Hard Core February 1984 Hard Core Feb 1984
Practical Computing - April 1984 Apr 1984
Hard Core April 1984 Hard Core Apr 1984
Call-A.P.P.L.E. - May 1984 May 1984
Byte May 1984 May 1984
Apple User – May 1984 1 May 1984
Hard Core June 1984 Hard Core Jun 1984
Call-A.P.P.L.E. - June 1984 Jun 1984
Practical Computing - July 1984 Jul 1984
Apple User - July 1984 Jul 1984
Personal Computer World - August 1984 Aug 1984
Call-A.P.P.L.E. - August 1984 Aug 1984
Apple User - August 1984 Aug 1984
Practical Computing - September 1984 Sep 1984
Call-A.P.P.L.E. - December 1984 Dec 1984
Call-A.P.P.L.E. - January 1985 Jan 1985
Apple User - February 1985 Feb 1985
Apple User - March 1985 Mar 1985
Call-A.P.P.L.E. - May 1985 May 1985
Call-A.P.P.L.E. - July 1985 Jul 1985
Orchard Computing Atumn 1985 Aug 1985
Personal Computer World - January 1986 Jan 1986
Call-A.P.P.L.E. - February 1986 Feb 1986
Personal Computer World Special: Business Computing The 1986 Survival Guide Apr 1986
Call-A.P.P.L.E. - June 1986 Jun 1986
Call-A.P.P.L.E. - October 1986 Oct 1986
Personal Computer World - November 1986 Nov 1986
Practical Computing - November 1986 Nov 1986
Call-A.P.P.L.E. - December 1986 Dec 1986
Call-A.P.P.L.E. - January 1987 Jan 1987
Call-A.P.P.L.E. - February 1987 Feb 1987
Call-A.P.P.L.E. - March 1987 Mar 1987
Call-A.P.P.L.E. - April 1987 Apr 1987
Call-A.P.P.L.E. - May 1987 May 1987
Call-A.P.P.L.E. - June 1987 Jun 1987
Call-A.P.P.L.E. - August 1987 Aug 1987
Call-A.P.P.L.E. - September 1987 Sep 1987
Personal Computer World - November 1987 Nov 1987
Personal Computer World - December 1987 Dec 1987
Byte April 1987 9 Sep 2009
Byte January 1985 16 Sep 2009
Byte October 1986 16 Sep 2009

This exhibit has a reference ID of CH31495. Please quote this reference ID in any communication with the Centre for Computing History.

 

ITT 2020 Computer - Apple II Clone

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