From: Bill Sudbrink <>
Date: Fri Jul 16 16:58:34 1999

I meant to post this Tuesday, but things got busy.
My IMSAI is up with the front panel, CPU and
memory card. I can now reliably do all front
panel operations and can toggle in and run short
programs on either the 8K SRAM or 64K DRAM card
(only one in the box at a time). For those keeping

Replaced all chips on the front panel. All are
now socketed.

Replaced two switches on the front panel.

Routed several traces around burned or otherwise
damaged spots on the front panel.

And... (this is the kicker)
Re-patched the MWRITE circuit. The original (and
incorrect) patch brought the SOUT signal to U25
pin 5. What was actually required at U25 pin 5

So next, I suppose, is to get the MIO working
(at least the serial port) so I can get a terminal
on this baby. If anybody has MIO REV.2 schematics,
it might make my life easier. To begin with, all the
chips on this card are socketed. It is a very neatly
and carefully done soldering job. The following chips
are missing: U8, U11, U30 and U34. I can see the
silkscreens for U30 (74LS32) and U34 (8T20), but the
sockets hide the silkscreens for U8 and U11. Does the
absence of these chips simply indicate that one of the
functions of this board is disabled?

Bill Sudbrink
Received on Fri Jul 16 1999 - 16:58:34 BST

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