Though the phrase “I designed my very own computer” might seem extraordinary to the uninitiated, everyone with an fascination in contemporary personal computer hardware is aware of that there’s genuinely not significantly to it: get a circumstance, a motherboard with a CPU, some RAM and peripherals, and you are rather considerably there. What is way much more outstanding is building a total pc process from the ground up, as [Joshua Coleman] just did when he crafted the Coleman Z80.
And when we say “from the floor up”, we suggest it: every little thing down to the system bus was hand-drawn by [Joshua] himself. It does share a little something with modern PCs though: a strictly modular structure. There’s a Z80 CPU board, a ROM and RAM board, and even two modules that you could describe as a online video card and a seem card. All of these are designed on prototyping boards with a 40-pin edge connector and hooked up to a single backplane carrying the major procedure bus.
Designed as an experimentation system, the Coleman Z80 has lots of attributes that help tests and debugging, these kinds of as an adjustable clock generator and a several stunning vintage LED shows that present the status of the key bus. Enter and output are primarily via a serial website link and a 16×2 Liquid crystal display, but [Joshua] is presently preparing a keyboard interface and composite video output to give it that appropriate 1980s home computer vibe. The program is at the moment restricted to a ROM watch that enables standard I/O commands, but with 256 KB of RAM there is a great deal of opportunity for composing handy program.
Just as remarkable as the style and design alone is the actuality that this was [Joshua]’s 1st digital layout job we’ve undoubtedly found even worse first assignments! Over the yrs we’ve highlighted many amazing homebrew Z80 computers, this sort of as a tremendous-minimalistic board, a modular process dependent on the highly effective eZ80, and this adorable tiny just one that matches inside of an Altoids tin.