 So, I was in the surplus store the other day looking for interesting chips, like you do, and I found this big ol' TMS-9900 CPU from 1976. Well, this one was manufactured in 1983, so I brought it home and I wanted to see if I could power it up and make it blink some lights or something. It's an interesting chip, it's a 16-bit CPU and it only has 15 address lines. For some reason, they decided to call A0 the most significant bit. Same thing with D0. In terms of power supply, it needs plus and minus 5 volts and 12 volts. I can do that. The minus 5-volt supply takes just a small amount of current, so a little switching regulator should be fine for that. For clocking, it can go up to 3.3 MHz. However, it requires a 4-phase clock, and the phases can't overlap. Oh, and the clock lines are 12 volts. And it has a minimum clock speed because it's dynamic logic and can't be single-stepped using the clock. Why am I doing this again? Anyway, there is a support chip which generates the required signals, and I found a whole lot of them on eBay. I now have 40 times more than I need. Oh well, they were very cheap. Okay, let's wire up the clock generator chip, hook up the CPU with some minimal signals, reset it, and then see what happens. Main power supply, turn on. Great, no smoke. Seems to work. Here's the sequence from resetting the CPU. That's pretty cool. Maybe I can build some kind of retro system around this. I can add memory in a front panel, and more lights and switches, and a terminal and keyboard. It could be fun. Anyway, thanks for watching.