1972 Unisonic Calculator Diagnosis

This Unisonic calculator and clock isn't doing so great. The MK5010P is basically a consumer version of the MK6010 which was the first single-chip calculator ever. So there are probably some minor problems with how they were produced. It's a cool calculator but it's not that uncommon, I've seen two at goodwill, and there are cooler calculators, like the SOBAX, so I don't think it's really worth going all out to fix it. The negative voltage logic difficultly is actually more interesting to me than making it work. So if I do ever come back to this, it's because I want to have a go at that.