16bit EPROM operation guide

The PROM8908D was originally designed to handle the 8bit chip. For EPROM with only 16bit capability, you need using an adaptor and programming it in a special way: You have to do every operation twice, one to deal with the low byte(D0..D7) and the other to the high byte(D8..D15).

A complete process should be:
1. Set both DIP switches(totally 16 bits) on the adaptor to the same direction. This will connect half of the 16bit bus onto the terminal pin and open the other half to keep it in a pull-up state. Then you treat this chip as 8bit only and operate the programmer in the usual way.
2. After finished the first half programming, you switch all DIP switches to the other side to process another half of the chip in the same way.
3. Only after both steps worked successfully, the process is completed.

For large quantity of IC be processed, we recommend you doing the first half on all IC at the same time, and then switch to do all the other half.