The mysterious IC L (680 Project Update)
- My apologies to Bill and everyone else- I screwed up. The chip in
question, IC "L" on the 680 motherboard, is not a 74L123. Its a
74LS74, and is not necessary for normal operation- it's only needed
for Baudot I/O, which most people won't ever use. So leave the
socket empty. Bill, this means that that you still have some kind of
problem with your computer and more troubleshooting will be necessary.
Unfortunately, my 680 assembly manual is out being reproduced now, so
the only manual I had available is the online one at
It does not have a parts list or assembly instructions. I misread
those schematics and assumed that the IC L on the front panel was the
IC L on Bill's mother board. Oops.
Dan ("ragoo_sauce") sent me an email a few minutes ago with correct
information. He has temporarily posted the pertinent schematic
diagrams, parts list, and assembly instructions on his web site at
Please take a look at his site for the correct info.