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6809 computer with 8" floppy

woodchips

Experienced Member
Joined
Nov 4, 2012
Messages
423
Location
UK
These are some type of ex-military 6809 computer, so can't be sold outside of the UK.

See photo. Board size about 14" wide by 12" deep.
Top right is the 50 way connector to the 8" floppy, plus another I can't remember what it is for, possibly 3.5" floppy since I have seen these units with the smaller disc.
To the right is all the floppy interface, PLL, FD1771 chip. Then the 32K of 16Kx1 DRAM and four Inmos 1420 SRAM chips.
Under them are the 2732 EPROMs. To the left are the 6809 and 6844, then the 16 2114 video SRAM with character generator and video out. Under the SRAM is the 6845 and video logic.
Under them are some inteface chips with 68488, 6821, 6522, 6821, 6821 and a 9511 floating point chip.

Important note:- the 8" floppy is one of the early types, can't remember the make, but the +5V AND THE +24V are wired along the 50 way cable! Connecting a standard Shugart etc will result in instant demise of same! For pinouts look in the Exorciser floopy disc interface manual, that supported both these odd drives and the standard drives.

I have four of these. One is the PCB as you see it, might have the PSU and backplane, NO floppy, that was chucked after attempts to use it in a normal environment. These were put into RAE cases, the standard UK military transit case. One is less the RAE case, I needed it to house my welder rectifier. There are two still in their RAE cases. I have not actually looked at any of the cased computers, there are endless screens and screws to undo, I am assuming that they are the same inside.

Large and heavy, about 24x24x10" weighing about 20kg.

Price for the bitzer one £40, the other three with or without the RAE case (I might keep them) is £80 each. Collection only, can see what you are buying then. Located near Grantham.
 

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I doubt it.

They are special computers built to test something or the other, and can't imagine them using an off the shelf OS. Disc possibly just used to store test data.

Need a logic analyser to find out the various IO addresses, disassemble the EPROMs etc.
 
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