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Old 17th Jun 2019, 4:46 am   #96
TonyDuell
Dekatron
 
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
Default Re: Gemini 80-Bus System

Here, as promised, are details of the boards in my machine.

There are 3 boards in the backplane :

GM829 Issue 2 FDC/SASI. This is cabled to the floppy drive and to a Xebec board linked to the ST412-interface hard disk.

GM812 Issue 2 IVC. Has ROMs IVC-MON V2.0 and IVC-GEN V1.0

GM813 Issue 3 CPU. Has ROM Simon V3.1MP

The IVC board has cables to the lightpen socket (5 pin DIN), video output (SO239) and Keyboard (DA15) on the rear of the case. I do find the use of a 1/4" jack for the video connector on the board a little odd.

The CPU board has cables to the cassette socket (5 pin DIN), serial (DB25) and parallel (36 pin Microribbon ('Centronics')) on the back. There's also a network card screwed to the side of the cardcage, its ribbon cable would fit in place of the parallel socket cable on the CPU board.
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