CPCFAX

Z80 Viewdata client for Amstrad CPC + M4 Board.

This project connects an Amstrad CPC to telnet-style Viewdata services over wifi using the M4 board, with a UI and renderer designed for a classic CPC experience.

• Optimised Viewdata/teletext style rendering
• Profile presets (including amshole and telstar)
• Disk image output for CPCemu

Building

bash tools/build.sh

Build output:

• build/harness_m4.bin (raw binary at 0x1000)

Create an AMSDOS-ready binary and .dsk:

bash tools/make_dsk.sh

Expected outputs:

• build/CPCFAX.BIN
• build/CPCFAX.dsk

make_dsk.sh also copies the disk to:

• ~/Library/Application Support/CPCemu/DISC/

What You Need

• sjasmplus (local copy included at repo root)
• Python 3 (for AMSDOS header generation)
• iDSK (local copy included at repo root)
• CPC with M4 ROM (or CPCemu setup that matches your workflow)

Run It

Boot your disk in CPCemu or on real hardware, then:

RUN"CPCFAX.BIN"

Pick a profile, enter or accept a host, and connect.

Repo Layout

• src/harness_m4.asm main program and UI flow
• src/vd_engine.asm Viewdata parsing/render core
• tools/build.sh assemble raw binary
• tools/make_dsk.sh wrap binary + build .dsk
• tools/add_amsdos_header.py add AMSDOS header

Screenshots

Below are the current project screenshots from images/:

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License

Copyright (C) 2026 Fergus Leen.

This project is licensed under the GNU General Public License v3.0. See LICENSE for the full text.