Its really nice to see classic computer tech like this that is still working today!
@JohnHamerProjects
3 ай бұрын
It's amazing how well the ond stuff holds up if you take care of it.
@LynnDrumm
10 ай бұрын
It's really nice to see people tinker with and explore s100 stuff! looking forward to the next one!!
@JohnHamerProjects
10 ай бұрын
Thank you! Trying to get some other project done. An update on this should be it soon.
@jeffnay6502
10 ай бұрын
Nice work. I am sure you had a lot of fun, putting this back together. I had three of them that I was able to purchase all around the same time. So, I had a lot of fun putting them all back together.
@JohnHamerProjects
10 ай бұрын
Yes, I've wanted one for a long time. Just need some free time to troubleshoot the remaining issues
@jeffnay6502
10 ай бұрын
@@JohnHamerProjects Here is one of the videos that I made on my dueling IMSAIs. kzitem.info/news/bejne/r69nnmF3q56Ea4ofeature=shared
@kerryedavis
7 ай бұрын
Very clean inside, etc. Nice! But not counting the other options, Even the "real" IMSAI 8080 and the "real" Altair 8800 still had fake front panels. Those CPU chips didn't have enough pins to directly have the front panel lights and switches connected. What happened was that the "front panel" actually consisted of a ROM chip with tiny programs that input/output the front panel switches/lights to the CPU via the regular input/output lines. Nothing like the original PDP-8 etc, - especially the PDP-12 which was a GORGEOUS thing! - where the front panel switches and lights were directly connected to the circuits.
@JohnHamerProjects
7 ай бұрын
It is an original Imsai 8080 front panel and there are no roms on it. The only reproduction board is the CPU board.
@kerryedavis
7 ай бұрын
@@JohnHamerProjects I didn't specify where the ROM chip is, but reading through the IMSAI 8080 technical manuals "back in the day" I found the lists of the CPU instructions that were force-executed to display the registers on the LEDs etc. So it's happening somewhere, and what else could it be other than some kind of pre-programmed ROM?
@JohnHamerProjects
7 ай бұрын
Read the schematic. It makes sense.
@JohnHamerProjects
7 ай бұрын
The Imsaiguy and johns basement KZitem channels go through how it works in pretty good detail. I am going to troubleshoot the examine switch not working in the next video and I'll try to go over it.
@kerryedavis
7 ай бұрын
@@JohnHamerProjects The schematics were there too. How else could it work? There simply aren't CPU pins for the A register, for example. So it has to be displayed by CPU instructions, unlike the previously-mentioned PDP-8 etc. Take a look at the actual manual, dunfield.classiccmp.org/imsai/cpa.pdf at page 4-4, starting with the 3rd paragraph. Forcing the CPU to execute certain instructions is a form of read-only memory even if it's hard-wired with diodes or something.
@epsyuma
9 ай бұрын
I built mine in 1979. I still have it. You might want to think about replacing that big power supply with a new switching supply. If those are the original caps, they are getting very dry and will eventually fail. You should check to see if they are leaking from the bottom. You will see some brown junk on the chassis underneath the caps.
@JohnHamerProjects
9 ай бұрын
That's awesome! The caps don't show any signs of leaking, so I think I'm going to keep it original for now. I'll definitely keep an eye on them. Do you still have your IMSAI?
@epsyuma
9 ай бұрын
@@JohnHamerProjects - Yea, I do. I actually have 2 of them. One I picked up as a trade for a PET computer.
@BenM39435
7 ай бұрын
wow, amazing man! Thanks for sharing! really cool to watch!
@JohnHamerProjects
7 ай бұрын
Thanks for watching! Hopefully I will get some time to get the front panel fixed soon
@kerryedavis
7 ай бұрын
Also, the 8080 instruction set is really better oriented towards octal than hex. For machine-language use with the front panel lights/switches, it would make more sense for the switches to be color-grouped as 2 switches, then 3, then 3.
@IMSAIGuy
10 ай бұрын
welcome to the party. my channel has lots of Imsai videos that may help you
@JohnHamerProjects
10 ай бұрын
Thanks! I've seen all your IMSAI videos. Big fan! Love chip of the day.
@uni-byte
11 ай бұрын
I'd love to have one of these. I've got a re-make of the Altair and a simulated clone of the IMSAI but it's not the same as having the real iron. BTW sound is only coming out the right channel.
@JohnHamerProjects
11 ай бұрын
Oh no! Thank you. New microphone
@JohnHamerProjects
11 ай бұрын
I've wanted one of these for a long time. I'm glad I finally pulled the trigger.
@uni-byte
11 ай бұрын
@@JohnHamerProjects I've wanted one since 1976 when they first came to the computer shop down the road from where I lived. I thin it was like $600 CDN for the kit. My car cost less than that. One of these days..
@JohnHamerProjects
11 ай бұрын
I learned machine language/as language from an altair emulator program like 20 years ago when I was in college. That's what sparked my interest. The alrairs are so expensive. I might get a clone one day.
@uni-byte
11 ай бұрын
@@JohnHamerProjects These days you can re-build the Altair from new parts. Search for 'altair 8800c ". Of course there is also the clone for a lot less effort and money.
@hitension7
3 ай бұрын
Problem with your audio - left channel is completely silence.
@JohnHamerProjects
3 ай бұрын
Yeah, sorry about that. Didn't realize it until it was up for a while. I was using a new mic and had it in the wrong mode.
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