Disclaimer fun: Electronics is just a hobby of mine and I dont claim to be an expert at anything. Nothing has been extensively bug tested and there's no guarantees, warranties, claims of suitability etc. Information and code is provided (largely uncommented) for research only, but please credit me if you find it useful - thanks.

FPGA Schematics: (Xilinx ISE 7.1 format project file archives)

V4 Graphics System V118
V4 MainBoard Controller V116

Z80 Source Code:

Z80 Protracker Replay Routine V4.18 (pretty much hardware agnostic)

Documentation etc:

V4 Hardware Reference info IE: RAM layout, ports, registers etc - Doc file

More files as and when...