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Found this in an 800 OS card


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One of it's inputs is 0xD7xx region which was used

for the Byrd ram upgrade. The extra chips are where

this one doesn't fit the Byrd though, the Byrd just

tapped pin #7 from from the 138 and took it to slot

20 and that's all that was done to the OS board.


They could be refining the address down to 0xD7Fx

or further?


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Two others things about this 800. There is ribbon cable running from the inside pins of the SIO port to another sio port cut out of the rear of the case. And there is a LED in the front of the case just in front of the space bar. It goes to CR210 and CR202 on the power PCB, the contacts closet to the front of the case. There are no modifications to any of the ram cards. I have not pulled it completely apart to see the CPU or motherboard yet.

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