Though the phrase “I designed my individual computer” might seem extraordinary to the uninitiated, anyone with an desire in contemporary laptop components knows that there’s truly not much to it: get a circumstance, a motherboard with a CPU, some RAM and peripherals, and you are very significantly there. What is way more extraordinary is planning a total computer system procedure from the floor up, as [Joshua Coleman] just did when he developed the Coleman Z80.
And when we say “from the ground up”, we suggest it: all the things down to the technique bus was hand-drawn by [Joshua] himself. It does share anything with fashionable PCs though: a strictly modular structure. There’s a Z80 CPU board, a ROM and RAM board, and even two modules that you could explain as a movie card and a seem card. All of these are designed on prototyping boards with a 40-pin edge connector and hooked up to a solitary backplane carrying the principal process bus.
Designed as an experimentation system, the Coleman Z80 has lots of options that empower testing and debugging, these kinds of as an adjustable clock generator and a handful of lovely vintage LED shows that exhibit the status of the primary bus. Input and output are primarily by means of a serial backlink and a 16×2 Lcd, but [Joshua] is currently preparing a keyboard interface and composite movie output to give it that suitable 1980s residence computer vibe. The software package is currently confined to a ROM watch that permits primary I/O instructions, but with 256 KB of RAM there’s plenty of likely for composing practical application.
Just as outstanding as the style alone is the truth that this was [Joshua]’s 1st electronic layout task we have undoubtedly observed worse to start with initiatives! Over the a long time we’ve featured many amazing homebrew Z80 personal computers, these as a super-minimalistic board, a modular system dependent on the highly effective eZ80, and this adorable minimal a person that suits inside an Altoids tin.