1138680b Project Update
- Mar 1, 2007Here are my latest 680b restoration project notes.
1) Steve Shepard sent me an ACIA monitor prom which seems to be
working. I toggled through the first 26 or so address bits and the
data matched the prom code. No monitor dot prompt however. Checked
using two terminals and hyperterminal/laptop.
2) Also with help from Steve Shepard, learned that the IC in position
L, 74L123 is missing. I located the position in the schematic to
match/confirm. Steve suggested that I review every chip and
connection to be sure nothing else is missing/incorrect. I am in the
process of doing this now. I assumed that the missing IC was supposed
to be that way, my mistake!
3) I have taken hi-res photos to aid in the analysis. I have posted
the new pics at the *bottom* of this page, if anyone is interested. I
also have a link to some of the manuals.
4) I checked my chips on hand, I do not have a spare 74L123. If
anyone here has one for sale, please let me know. I found a site that
may be able to help, but I have not called them.
Summary - Given (A big assumption) that all of the soldering is OK, I
hope that installing a 74L123 in IC L will get me to a dot prompt
finally. You can see from the pictures that this is definitely a kit,
and that some connections were changed at some point.
That's all..off to work!
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