26 Apr
2010
26 Apr
'10
10:31 a.m.
I obtained an Intel SDK-85 eval board some time ago and decided to try
to bring it back to life today. It had been part of a Philips logic
analyzer demo system apparently. They had cut off the prototyping area
on the left side and put their own board there instead... which had a
2716 EPROM on it and some hardware to generate glitches as part of the
logic analyzer demo I guess.
In any case, I undid all of their mods (except of course, putting the
sawed off prototype section back on!) and the unit sort of works.
What I have discovered is that the 8355 ROM+IO chip is flakey. It won't
work unless I freeze it with component cooler. Once I have done that,
then it starts working and stays working for hours as long as power is
not removed. If it gets powered down, then I have to freeze it again
before the device will respond with valid fetches.
I don't suppose anyone has a spare 8355 with SDK-85 monitor burned in
it do they?
Alas not. But if the device works if you cool it, can't you read it out
when it's been cooled? Surely the SDK-85 has some kind of I/O port
you could dump it to. And then burn the bits into an 8755 as you suggested.
-tony