Although the phrase “I designed my particular person pc” might sound extraordinary to the uninitiated, anybody with an need in modern laptop computer parts is aware of that there’s actually not a lot to it: get a circumstance, a motherboard with a CPU, some RAM and peripherals, and you might be very considerably there. What’s far more extraordinary is planning a complete pc system process from the ground up, as [Joshua Coleman] simply did when he developed the Coleman Z80.
And after we say “from the bottom up”, we propose it: all of the issues right down to the approach bus was hand-drawn by [Joshua] himself. It does share something with modern PCs although: a strictly modular construction. There’s a Z80 CPU board, a ROM and RAM board, and even two modules that you possibly can clarify as a film card and a appear card. All of those are designed on prototyping boards with a 40-pin edge connector and hooked as much as a solitary backplane carrying the principal course of bus.
Designed as an experimentation system, the Coleman Z80 has plenty of choices that empower testing and debugging, these sorts of as an adjustable clock generator and a handful of pretty classic LED exhibits that exhibit the standing of the first bus. Enter and output are primarily by the use of a serial backlink and a 16×2 Liquid crystal display, however [Joshua] is at the moment getting ready a keyboard interface and composite film output to provide it that appropriate Nineteen Eighties residence pc vibe. The software program bundle is at the moment confined to a ROM watch that allows main I/O directions, however with 256 KB of RAM there’s loads of probably for composing sensible software.
Simply as excellent because the model alone is the reality that this was [Joshua]’s 1st digital structure process we now have undoubtedly noticed worse to begin with initiatives! Over the a very long time we’ve featured many wonderful homebrew Z80 private computer systems, these as a super-minimalistic board, a modular system depending on the extremely efficient eZ80, and this cute minimal an individual that fits inside an Altoids tin.