Front Panel Madness

Discuss construction, troubleshooting, and operation of the Altair 8800c computer

Re: Front Panel Madness

Postby Ttpilot » February 8th, 2022, 1:21 am

Results can be seen at http://hawken.sdsmt.edu/367_at_A-E-G.mov. The LS367 chips seem to have fixed the A1 and D6 problem. The HLTA is still present, and DEPOSIT/DEPOSIT NEXT don't seem to be working. Also A8-A15 are lit upon reset, then go away during operations unless I set the the system to addresses in that range. Then they seem to work okay.

I should get my new LS367 chips on Wednesday. Let's hope that fixes the whole thing
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Re: Front Panel Madness

Postby Ttpilot » February 8th, 2022, 1:28 am

FWIW, all the chips on the cpu board were from a kit someone was selling on eBay. I wonder if they got a bad batch of 8T97s. The 74LS123 instead of 74123 at IC-Q was also in that kit
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Re: Front Panel Madness

Postby Ttpilot » February 9th, 2022, 6:34 pm

I must be under some kind of curse lol. Digikey sent me my order for 74LS367s, but they filled it with 74HC4050s. Gotta wait for them to ship the correct chips
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Re: Front Panel Madness

Postby AltairClone » February 9th, 2022, 11:39 pm

Oh man, how frustrating!
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