While the expression “I constructed my very own computer system” may seem excellent to the inexperienced, any individual with a rate of interest in contemporary computer understands that there’s truly very little to it: get a situation, a motherboard with a CPU, some RAM and also peripherals, and also you’re practically there. What’s means a lot more excellent is developing a total computer system from scratch, as [Joshua Coleman] simply did when he built the Coleman Z80.
And also when we state “from scratch”, we imply it: every little thing to the system bus was hand-drawn by [Joshua] himself. It does share something with contemporary Computers though: a purely modular layout. There’s a Z80 CPU board, a ROM and also RAM board, and also also 2 components that you might refer to as a video clip card and also an audio card. Every one of these are improved prototyping boards with a 40-pin side adapter and also connected to a solitary backplane lugging the primary system bus.
Created as a testing system, the Coleman Z80 has lots of functions that allow screening and also debugging, such as a flexible clock generator and also a couple of stunning vintage LED display screens that reveal the standing of the primary bus. Input and also result are generally via a serial web link and also a 16 × 2 LCD, yet [Joshua] is currently preparing a key-board user interface and also composite video clip result to offer it that appropriate 1980s personal computer ambiance. The software application is presently restricted to a ROM display that allows standard I/O commands, yet with 256 KB of RAM there’s lots of capacity for composing valuable software application.
Equally as excellent as the layout itself is the truth that this was [Joshua]’s very first digital layout task; we have actually definitely seen even worse very first jobs! Throughout the years we have actually included a number of amazing homebrew Z80 computer systems, such as a super-minimalistic board, a modular system based upon the effective eZ80, and also this adorable youngster that fits inside an Altoids tin.