SWTPC 6800 weirdness

Fred Cisin cisin at xenosoft.com
Tue Sep 6 13:35:52 CDT 2016

On Tue, 6 Sep 2016, Brad H wrote:
> My 6800 has been mostly working, but it seems to be occasionally flaking
> out.  I don't know why.  Sometimes you go to power it up, and there's no
> response on terminal side.  The 'fix' is sometimes to wiggle the memory/CPU
> boards and then for some reason it's fine(ish).  There are five cards

fix by wiggling implies a bad connection.
possibly due to oxidation or corrosion of connector?
Depending on how vigorous the wiggling is, it could even be bad connection 
between a chip and socket, or even tiny damage to a trace on the board.

> Today it flaked again and would not come back up, so I pulled the MP-M board
> and the MP-A board and swapped slots.  It came up, but memory at $0100 was
> missing.    I tried powering up, swapping slots, etc.. same deal.  Then I
> left the machine for an hour, powered up again.. boom.. now $0100 is back.

Working later could be a thermal problem, or just random chance.

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