Tag Archives: breadboard

6502 homebrew: display and keyboard problems

The Apatco 6502 breadboard computer kit I’ve been building is complete. The next stage was to make it more so. A word of warning, though. This story does not have a happy ending. Nonetheless, someone may find the attempt at debugging entertaining or instructional, so here it is. The kit is sold (or perhaps ‘was’ would be better, as it… Read more »

6502 homebrew: debugging the kit #2 [solved]

If in doubt, start again. That’s not a real saying, but it should be. As we saw in the last post, the Apatco 6502 breadboard computer was finally wired up but refusing to work. I’d fixed my faulty ROM code, buzzed out all the address and data lines to check they were connected correctly and determined that the reset circuit and… Read more »

SmartParallel: breadboard prototype

A major reason for doing breadboard prototypes is to learn what mistakes you’ve made in your circuit design. Of course, it’s also a way to introduce brand new errors. Or both. Before committing to fabricating PCBs, I wanted to check out whether my design for the SmartParallel dot matrix printer interface would even work. My confidence was reasonably high because,… Read more »