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

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.