EagleCAD schematics and layout of Marcel van Kervinck's TTL VGA Computer
This is an 8-bit Harvard architecture cpu developed by Marcel van Kervinck - as a practical CPU using simple TTL logic to create a VGA display of 160 x120 pixels in 6-bit colour.
Marcel's original design may be found on HackaDay here: https://hackaday.io/project/20781-8-bit-color-computer-from-ttl
The aim was to develop a practical 8-bit CPU using a minimum of TTL packages - with emphasis on using only those parts that are commonly available.
This repository begins with a transcription of his design to EagleCAD so that the circuit schematic may be better understood and different layout options evaluated.
Marcel has produced a pcb for his design using KiCAD - approximately 9"x6". However it may be feasible to get the design onto a more compact 6"x4" Eurocard - especially if SMT TTL parts are used.
The files here are in a draft form and are missing some key control signals. They are for information only and do not currently represent a 100% complete transcript of Marcel's design.