Tube🌿Timeso i have picked up an INS8900D, also known as the National Semiconductor PACE. it is the first commercial 16-bit microprocessor. let's take it for a spin!
according to the datasheet, it is an NMOS device, and it requires three power supply voltages: 5V, 12V (!) and -8V (!!). the 5V supply is for the IO, the 12V supply is for the core voltage, and the -8V supply is the substrate bias.
bitsavers.orgis there any criticality to the order that power supplies come up on with three voltage NMOS parts? is it possible to damage a part if one voltage is missing?
@bitsavers don't think so as long as none of the voltages go below the -8V rail