So progress but now this, it shouldn't be this complicated but I also forget how to extract an rar. properly so yay I have unarchiver and 7zip but both extract the rar. as a Experian Profiler .exe. here's what I get with doing what you said.
We are still looking at screen the original tech step uses a membrane keypad now we want the roms on board so we will need switches or something of the sort like jumpers to choose a ROM. As far as screens go maybe touchscreen could work I'll see what's what.
You can test for bad ram in a machine so say you put a board and power supply on a work bench you can swap modules and the TechStep will identify good or bad even if they seem good.
Everything looks okay on my end @retr01. Also @splorp I know there’s one for $70 on eBay in box otherwise download the files on page one and there’s a resource showing what power supplies are compatible.