For those unaware, the Intel 1702A was the first commercial EPROM. It held 2 Kbit (256x8 bytes). To program it, one needed four different voltages (one of which was negative 48 volts), but curiously, no ground reference.
Remember programming these when in college in the 1970s. We bought some surplus (probably out of spec) 1702s. The programmer would have trouble programming them until we noticed how hot they were getting. We spayed them with freezing spay to cool them down until the programmer finished.
Interesting. Just too hard to debug for software side people like me. But very interesting.