First posted March 22, 2002
Last Update May 27,2002
This is a fairly simple module, but also a very expensive one to build, as it has 128 PC mount toggle switches on it. The module has four logic input. This selects one of 16 switch rows. The 8 outputs depend on the switch position. You can sort of think of this thing as a really small "prom".
The board photo below has everything on it except the LED's...I have to say, this was a real bitch to build. Getting all the switches to line up with the holes on the panel wasn't exactly easy.
Also, please note, in the schematic, all of the diodes that are in the switch matrix are backwards.
Patern Generator PC Board photo
PC Board Layout