I’ve been working on this site and the following changes have been made:

11th July 2020

  • Minor updates to the GM886 page.
  • A couple of updates to the Gemini numbers list.

10th July 2020

  • GM886 High Performance 80286 board added. Does anyone have any information on this?

30th June 2020

  • GM832 (SVC) drawing link fixed. Now available in full size.

29th June 2020

  • More info on the GM860 EPROM programmer. Does anyone have the manual and software for this? Any formats would be fine.

11th June 2020

  • History page jazzed up with some clippings. WW info also added.
  • WW info added to System-80 page.
  • Minor tweaks to GM821 and GM827 keyboard pages.
  • GM923 added to Gemini numbers list.

10th June 2020

  • Advert for System-80 added.

9th June 2020

Just a comment. Although I’ve used material (photos etc.) from other sources I’ve generally done so with permission – even if I haven’t credited such in every case. I’m not in the business of “asset stripping” other sites either, so I’ve always attempted to take only a small amount from each site. However, there is a very small amount of information available in some cases – particularly on Gemini systems –Β  and I particularly want to bring a lot of it into one place where it can be easily found. Consequently you’ll find stuff here that has been taken from elsewhere and I make no apology about that. You’ll also find original photos that I’ve taken and documents that I’ve scanned myself or that have been graciously donated by others. – Mick

  • Added some info on the cancelled System-80 system
  • Changes to the History of Nascom & Gemini
  • Changes to the Nascom-3 section
  • Changes to the Lucas disk system page
  • New page added for NAS-DOS
  • “Smart 1” board advert added to Other Stuff

7th June 2020

  • NAS-DOS added to Nascom Disk Systems
  • Lucas floppy disk controller added to Nascom Disk Systems
  • Lucas floppy disk systems added Nascom Disk Systems
  • More info on the Animation Graphics board

4th June 2020

  • More updates to the Definitive Gemini Numbers List
  • Nascom-3 page re-written with *NEW* photos! πŸ™‚

3rd June 2020

  • More info added for the “GM836 Multinet” board.
  • Definitive Gemini Numbers list added.

2nd June 2020

  • Info added to “The Magazines” including cover scans. This has involved several new pages and quite a lot of new pictures!
  • A little tweaking of the Gemini keyboards info.

20th May 2020

  • General “tweaking” of all the Nascom monitor pages.

16th May 2020

  • More info added to PolyDos page regarding different versions.

15th May 2020

  • Info on SIMON and BIOS compatibility added to Gemini Disk Systems.
  • Specification & Price List added to Pluto Graphics board (1982).
  • More info added to Pluto Graphics board (1986). Pluto 1A?

5th May 2020

  • More info on PolyDos.
  • Minor updates to Disk Systems in Gemini section.
  • Update to CP/M section.
  • Library tidied up to make it easier to navigate & maintain.

4th May 2020

  • New info on Henelec/G805 disk controller added.
  • G809 FDC page edited.
  • Starting to include some Polydos info.

3rd May 2020

  • G682 bus system entry expanded.
  • A note on CP/M added to the Gemini Software section.
  • A new section on Disk Systems added for the Gemini system.
  • Some updates to the Cased Versions section.
  • “A Note on keyboards” had GM812 instead of GM821. GM812 is the IVC card.
  • Disk Systems in Nascom section updated. Links from pics fixed.
  • RP/M section now includes info on version 2.3

29th April 2020

  • A little more info on the Henelec / G805 disk system.
  • More info on the British Micro Mimi computers.
  • Download page added, with drawings for Nascom 2.

15 July 2018

  • A little more info on the G801 Mimi.
  • GM853 “Bytewide” updated.
  • GM863 Battery-backed static RAM added.
  • More info on G802 64k dynamic RAM.
  • Does anyone know what GM861 was?

13 July 2018

  • More info on GM827 keyboard.
  • Gemini Galaxy 1 advert added to Publicity page.

4 July 2018

  • Changes to A Note on Keyboards.
  • Changes to GM827 keyboard page.

28 June 2018

  • A Note on Keyboards added to Gemini section.
  • G801 Mimi computer added.
  • Nascom AVC card added.

27 June 2018

  • Slight changes to GM827 & GM852 keyboard pages.

25 June 2018

  • More pictures of the Kenilworth case.
  • Imp Printer added.
  • Minor changes to Notes on Video Systems.
  • Much more info on GM836 network card.
  • A little more info on the IVC and SVC cards.
  • Starting to get my head around Gemini’s pre-built systems…..Β  😦

24 June 2018

  • Slightly more detail on the SVC card. It DOES support a serial keyboard!
  • More information on NASBUS.
  • A couple of pictures added to “History”.
  • Kenilworth Case added.

21 June 2018

  • GM852 keyboard added. – Looking for more info!
  • Slightly more info on GM812 keyboard.
  • More info on GM827 keyboard. – Looking for more info!
  • More info on GM853 “Bytewide” card.

18 June 2018

  • GM812 keyboard info updated.
  • New photo for GM803 and manual added.
  • More info on G802 64k DRAM added, including new pics, manual & circuit.
  • * G806 ‘Supermum’ board added.
  • More photos, manuals etc. added for G809 FDC.
  • Hardware Manual for G811 Z80 card added to page.
  • Added more links to manuals on the Library page.
  • * GM827 87-key keyboard added.
  • Added a couple of notes to History re G/GM part numbers.
  • Text changes to G811 info.
  • Quite a few changes on GM813 page.
  • Corrections to IVC. IVC & SVC do not support serial keyboards.
  • Updates & corrections to G832 SVC.
  • * GM815 floppy disk system added.
  • A little more info added for GM824 A-D card.

4 June 2018

  • Minor text changes to About page.
  • Publicity section added.
  • Buffer board photo changed as original was small & unclear. This one is still rather unclear but bigger.Β  πŸ™‚

27 May 2018

  • Added circuit diagram of GM860 EPROM programmer. (Thanks Daniel)

21 May 2018

  • Added some info on a ready-built Gemini system. (Thanks Daniel for all of these!)
  • Added GM849A disk controller to GM849 page.
  • Added GM824 A-D converter board.
  • Added GM853 Bytewide board.
  • A little more info added to GM808 EPROM programmer.
  • GM862 256k RAM added.
  • GM880 Z180 processor board added (this is a real gem!)
  • Pluto graphics card (1986) added.
  • Prototype static RAM disk added.
  • Added IO828 Pluto card & manuals (Thanks to Richard at 80-bus.com)

10 November 2017

  • Info on G811 Processor board corrected updated.
  • Added some detail of the SIMON boot EPROM. (Updated 11/11/17 and 12/11/17)

3 November 2017

  • Added more info on NASBUS & 80-BUS

31 October 2017

  • Added GM832 SVC hardware manual. (Thanks Steve!)
  • Added GM821 Parallel keyboard.
  • Added info on the NASBUS.

23 October 2017

  • Added more info, including circuit (thanks Steve!) on the GM811 processor card.
  • Added info on RP/M (thanks again Steve! πŸ™‚ )

1 July 2017

  • Added GM808 EPROM programmer

16 June 2017

  • Updated the Nascom-1 page with more photographs.
  • Additional photo added to RAM-B Board.
  • Manual added for the Henelec Prom-Prog.

13 June 2017

  • GM860 EPROM Programmer added.
  • New photos for Henelec EPROM programmer.
  • Better copy of Nascom 8A supply manual.

12 June 2017

  • New photos for Nascom-1, Nascom-2 & Nascom-IO board.
  • New photo & update to G812 IVC card.
  • New photo for G848 serial card.
  • Henelec EPROM programmer info updated.
  • Bigger pictures in Notes on Video Systems

11 June 2017

  • Updated G833 info.
  • Minor updates to the History section.
  • Updates to The Hobbit info.

9 June 2017

  • Added EPROM & FPCS boards
  • Many photos replaced with better quality ones.
  • Started a library of various manuals.

8 June 2017

  • Henrys Radio Nascom-1 brochure added.
  • Much more info about the Nascom keyboard.
  • Restored a lot of Gemini specific pages to this site that had gone missing in the move 6 years ago. πŸ™‚
  • Added a link to 80bus regarding info on Gemini cards.
  • More info on the 80-Bus added.

Found thisΒ link to youtube about a GM925 computer – one that I didn’t know about. It is built using the GM813 processor, GM832 SVC card and GM849 FD drive card.

Added this page. πŸ™‚


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