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I know the original magazine articles have parts lists and schematics, but are there any modern/cloud lists availble? Perhaps with digikey/mouser links and part numbers?

Hey, For anyone interested in building an Altair 8800 replica you'll need a case. Until recently Mike Douglas had been producing theses over at https://deramp.com/. Unfortunately after doing them for almost a decade he recently decided to stop. The good news is that Chris Davis of https://adwaterandstir.com/ seems to have picked this up and is making Mike's cases again! If you need one you can get one here https://adwaterandstir.com/product/altair-reproduction-case/ Mike still produces a front panel set and controller board that is S100 compatible here https://deramp.com/altair_8800c.html So it is possible to build a full S100 replica of the Altair using this case. I have one on order, along with the front panel boards. Once they arrive and I start building my replica I will share my progress here. Cheers, Gavin.

Hey, So following on from my earlier post regarding some LS logic ICs not working in my Mark-8. I think I may have an issue with the 74LS75 latches that I have. Firstly they seem to work fine on a breadboard test circuit. I can get them to latch data without any issues. However if I input the test program on page 9 of the construction guide and run it the display shows this: Rather than counting up on the output port bit 3 gets stuck on and all the other bits show very brief flickering. It's executing code fine. I can single step and see it working. Interestingly if I remove the delay loop at the end of the test program and do an unconditional jump back to the INCB instruction I am able to single step and watch it count. It works perfectly if I single step. The output port counts up as expected. But run it at full speed and it fails. If I scope the the enable lines on the latch with some of the input I get something like this: This is IC 7 on the LED output board. It's one of the 74LS75 latches. The scope shows the enable lines (in yellow) with the input from pin 7 that's the D0 data line. I set my scope to trigger on the enable lines rising edge. Have to say I am not sure about this? The enable pulses seem very quick? It's not latching that data either. Is this an issue with the enable line signal or a faulty batch of 74LS75s? I have swapped out IC 10 a 74LS02 and IC9 a 74LS42 with known good ICs and things don't change. Any thoughts? Gavin.