DIY 8-Bit Z80 Single Board Computer

This is an awesome Z80 Single Board Computer project I finished last year. It went through a couple of revisions over a few years, this is the final one. It has Zilog Z80 10Mhz CPU, 8Kb ROM, 8Kb VRAM, 48Kb RAM (64Kb total), 2 serial ports (Zilog SIO IC), 2 Atari-compatible joystick ports (first Zilog PIO IC), AY-3 sound generator by General Instruments, built-in mechanical keyboard (second Zilog PIO IC) and Zilog CTC clock chip servicing blanking video interrupts. This is Sinclair ZX Spectrum personal computer reimagined - it's what I wanted it to be. It has one demo game written for it - Boulder Dash clone, one application - graphics tile editor. And it has small debug monitor program built in the ROM. I plan to make BASIC interpreter for it and assembly language development environment after I finish making Window/Linux/Mac SDL-based emulator. Project web page: https://solisted.net/projects/z80-single-board-computer/ Schematics, gerbers and CAD files: https://github.com/solisted/z80sbc Emulator for Windows: https://solisted.net/projects/z80-sbc-emulator/ High quality manufactured PCBs of the mainboard and keyboard for sale: https://www.ebay.co.uk/itm/165783862203 It is very easy to build it yourself. No sophistication required to do it, it's completely made of through-hole components, very easy to solder at home. CPLD ICs are also very easy to program with inexpensive tools. I will make a separate video on how to work with Atmel CPLDs used in this project.