All the following were, at some time, sold under the Gemini name. Many of them were not actually manufactured by Gemini though. The expansion boards were all Nas-bus compatible, although the bus had now been renamed as the 80-BUS. The frames offered would only really accept the Gemini cards, as they were intended for the 8in x 8in format only rather than the 8in x 11in NASCOM computers. However, a NASCOM-2 would work as the CPU card even though it stuck out of the frame by 3in! The NASCOM-1 was of no use really as it needed special arrangements to fit it to the frame (but see the pictures of my machine to see how it was done!). The frames and motherboards were sold separately, so the motherboards were suitable for NASCOM systems if used without the frames. (Of course, many NASCOM systems DID fit into Gemini frames – the frame was never the same again though. You can work wonders with a bit of aluminium and a hacksaw!)

Many of the Gemini expansion boards were unsuitable to the NASCOM-1 due to insufficient I/O decoding on the main board. Also the lower clock speed of this machine meant that it couldn’t really be used with disk systems. However, with a bit of hardware modification and a little luck in running the NASCOM-1 at 4MHz, both these problems were solvable.

Several of the cards are coded Gnnn on the actual card, whereas they are advertised as GMnnn. This may be irrelevent, but I thought I’d better mention it.

Note that the Gemini Galaxy 2 and Quantum 2000 computers were advertised as using two Z80 processors. They didn’t happen to mention that only one was used as the system processor and the second as the graphics processor. Was this the beginning of “imaginative advertising” in computers?

Gemini Galaxy 2
GM903
Complete system with 2 floppy drives
Gemini Quantum 2000
Complete system
19in Frame
GM610
Not intended for use with the NASCOM system as it only accepted 8 inch deep cards.
GM656
Suitable for use with all systems.
5 Slot Motherboard
GM654
Suitable for use with all systems.
8 Slot Motherboard
GM655
Suitable for use with all systems.
5 board frame
GM662
Not intended for use with the NASCOM system as it only accepted 8 inch deep cards.
6 Slot Motherboard
GM682
Suitable for use with all systems.
64k RAM board
G802
64k dynamic RAM card
ROM board (90k)
G803
sold without EPROMs!
Disk controller
G805
48TPI cased system connected via the PIO
3A Power Supply
G807
EPROM programmer
G808
Re-badged version of the Bits ” PCs unit. For 2708 ” 2716 EPROMs
Floppy Disk board (92k)
G809 (dated May 1982)
48/96TPI – replaced later by GM829. This was not suitable for use with the NASCOM-1 due to the slow processor.
CPU board
G811
with 4 RAM/EPROM sockets (no RAM fitted)
IVC card
G812
Intelligent Video Controller – 80 char/25 lines
CPU/64k RAM board (192k)
G813
with RAM and CP/M compatible
IEEE488 board
EV814
Multi I/O board
G816
with 6 I/O ports, 4 CTC, RTC
6A Power Supply
G817
switch mode type
Twin Serial Port
G818
daughter board to fit G816 I/O board
Keyboard
GM821
59-key ASCII parallel interface keyboard with cursor keys
RTC board
G822
Real-time clock kit – plugs into PIO
A-D board
GM824
Re-badged version of an IO Research unit.
Floppy drive unit
GM825-1S or GM825-2S
1 or 2 5.25in floppy drive unit
Keyboard
GM827
Parallel interface keyboard with cursor and function keys
Static RAM board
MP826
32k static RAM with battery backup
87 key keyboard
GM827
with user-definable function keys + numeric pad
Disk Controller board
G829
Gemini – for 4 mixed 5.25in and 8in + SCSI HDD (Someone said that this was also used in the Lucas Logic “Winchester” hard disk drive!)
SVC Video Card
G832
Super Video Controller (enhanced IVC)- 80 char/25 lines
RAM-disk board
GM833
512k dynamic RAM. Virtual disk operation.
“Winchester” drive
GM835
5.4Mb (!) hard disk drive subsystem (1450 UK Pounds in 1983!)
Network adaptor
G836
Adaptor for their proprietory networking system.
Colour vector graphics
GM837
Re-badged version of a Climax board. 256×256 display. 16 colours. Much cheaper than the PLUTO system!
Prototyping card (58k)
GM839
14 Slot Motherboard
MP840
80-BUS card extender (164k)
GM841
10A Power Supply
G843
switch mode type
Serial I/O
GM848
4 serial ports + PIO
Floppy/SCSI
G849
also supports 1.2M drives – up to 8 devices
Keyboard
GM852S
Serial interface keyboard with cursor and function keys
EPROM programmer
GM860
“Bytewide” programmer with built-in mains supply.
Monitor
Badged Phoenix unit
12in green or amber phospher
PLUTO Graphics
IO828
High power (for the time) graphics board. This was a basic version of the IO Research board.