A brand-new, never-before-seen "Frankenstein" SOL-20
This SOL-20, though originally from the 1970s, had never before seen the light of day. The motherboard, keyboard, case, and PSU were all purchased from different vendors over a period of more than a year. The motherboard was originally sold as a kit, but after at least two hobbyists worked on it (given the two very distinct styles of soldering), it had never been completed. The keyboard is a New-Old-Stock (NOS) unit, yet defective: all capacitive foam pads were gone and a 74LS74 IC was shot despite having never seen use (flip-flop chips fail a lot). The PSU and case are likely the very last revision sold by Processor Technology, as they look nothing like the usual ones. In the PSU, the main transformer is mounted sideways and the main bulk capacitor vertically, the opposite of the usual arrangement. An LM323K STEEL regulator is used in the 5V line, also unlike the normal PSU. In the case, the usual masonite pieces are dispensed with, with the blue metal cover being screwed directly into the walnut side panels. This is a very peculiar revision I'd never seen before. And after drawing a blank on a post at the Vintage Computing Federation forum, I believe this is the first report of this revision online; perhaps a literally unique SOL-20.