eprom

EPROM programmer


Below is the drawing of how to connect an Eprom reader (programmer) to a 16 bit Input/Output unit described before. I did get the values from a NMOS 27128 eprom with this circuit. Recently I programmed a NMOS 2716 eprom without a problem. I only had to measure the programming-pulse time

Reader circuit

The PR line is not available on all eproms. Sometimes the OE or the CE lines take over the function of programming.


Here is the circuitry for the programming voltage, wich has to be switchable by the pio and supplied by an external power supply. The voltage value is not the same for all eproms!

Programming

A Basic program, written to read and program a 2716 Eprom, can be downloaded here. It can be used as a reference. Remember, I can not be held responsible for any damage!!!