I decided that my previous PCB design for the instruction buffer was too complex for what it really needed to do. The primary goal is to ensure that the execution modules take their instruction signals from buffers rather than directly from the EEPROMs. So I scaled the PCB design back to just a single set of buffers (24 bits) and a pair of 40-pin sockets that will be used to distribute the instructions to the boards. Recognizing that since it's a single-side board, I'm going to have to do some manual soldering anyway, I left the final leg from the buffers to the 40-pin socket empty, since trying to route those connections on a single-sided PCB would be a mess, and it will actually be tidier to simply solder in 24 wires on the back.
Here's the front with the components attached -- pretty slick, if I do say so myself!
Now I just need to get the last 24 wires soldered in and I can start working on the jump/shift unit.
Based on my experiences building this PCB, I expect that I'll implement the jump/shift unit in several "units," each of which is relatively easy to implement on a single-sided PCB. I'll then wire those together using wire-wrap (or solder, depending on the situation).
Hi, Interesting project. Just an observation, when creating PCB be it etched or milled please *fill* the spare copper area in your design.
ReplyDeleteThis saves etchant, it saves on etch time, it makes for much more reliable PCB and if you make the fill ground it may improve your electrical noise!