A Two Chip SB180FX EPROM Programmer
To support my project of modifying an SB180 to run at 22MHz I built a simple EPROM programmer.
I connects to the 8255 port on the SB180FX, uses two chips (one eight bit latch, and a
timer chip for generating the programming pulse). It is built onto a surplus plug-in
circuit card. It uses a wall-wart AC transformer, which supplies 20VAC to the board. The
AC is rectified and filtered on-board, and then regulated to the three DC voltages required
for programming: 5, 6.25, and 12.75 VDC. There are two switches: one for "Read or Program",
and one for switching signals around for 28 or 32 pin EPROMs. Someday I need to put it into
I have included a scanned image of the circuit sketch I used to wire the programmer. The
programming-pulse timer chip is not included, I think I just winged that one. This sketch
may or may not be of much use, but, there it is.
I wrote a couple of programs for this programmer. I will include them here soon.
Click on a thumbnail-image for a larger image.
|SB180FX EPROM Programmer
|SB180FX EPROM Programmer Circuit Sketch