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Two related projects provide a C development toolchain and a collection of CP/M applications and disk images for this computer. Together, they offer a path from C source on a modern development machine to applications running under CP/M on this project's real Z80.

Compiler & toolchain DCC C Compiler Build C applications on your computer. Run them on a Z80 under CP/M. Explore DCC Applications & disk images Altair 8800 AI Edition Explore CP/M applications and build disk images for this Z80 computer. Explore Altair

The disks supplied with this project already include a default set of applications. The system boots 64K CP/M 2.2, a custom version of the original Burcon CP/M 2.2 and BIOS, modified and optimised for the Z80 and this board. You can use these supplied disks when you reach the CP/M phases; building or importing additional applications is optional.

This is the application-development goal for the later stages of the project. Start with the staged hardware bring-up, completing the documented electrical checks and tests in Phases 0–8 before proceeding to CP/M disk deployment. Those phases establish correct power, clock, bus, SRAM, and I/O operation on your board.

Phase 9 introduces flash-backed disks, Z80 CP/M booting, and applications through the USB terminal. Phase 10 adds the WebSocket terminal. The deployment example below describes the completed Phase 10 system; follow each phase's own firmware and validation instructions as you reach it.

DCC C Compiler

The DCC C Compiler builds Z80 CP/M .COM applications on Windows, macOS, and Linux. It supports C89 with selected C99/C11 features, making it possible to write C applications with modern development tools for a CP/M target. Its documentation includes a C conformance guide describing supported features and target exceptions.

DCC translates C source into M80 assembly, then uses M80 and L80 to assemble and link the executable. Its dccmake command coordinates the build, and its runtime provides console and file I/O and other C library facilities suited to CP/M. See this project's CP/M and DCC compatibility overview for the runtime environment provided by the Z80 ROMless SBC.

Altair 8800 AI Edition

Altair 8800 AI Edition includes a collection of CP/M/Z80 applications in its Apps folder. The collection includes C applications built with DCC and tooling to package applications into 512 KiB CP/M disk images for the Z80 ROMless SBC.

Once the earlier bring-up tests pass and you reach Phases 9–10, use the following workflow to bring applications across from the Altair project.

In the ESP32 Altair 8800 AI Edition project

  1. Run Run interactive CP/M emulator in that project to edit its writable disks/512kb/ base images. These are also the build-all input/output disks. File edits persist directly; finish the application and stop with Ctrl+] in the task terminal before running a host build or copy.
  2. Stop the SBC emulator and save any wanted session changes too. In the Altair project's Apps directory, choose:
# Build/install applications, then copy A-D.
pwsh ./build-all.ps1 -c /path/to/Z80ROMlessSBC/src/disks/native

# Copy current CP/M disk contents without rebuilding applications.
pwsh ./build-all.ps1 -CloneOnly -c /path/to/Z80ROMlessSBC/src/disks/native

Build-and-copy replaces built application files but preserves unrelated files. Copy-only keeps current file contents without rebuilding. The existing destination directory is overwritten, including D's database. Equivalent ESP32 tasks are Altair: Build apps and copy disks to Z80 SBC and Altair: Copy current disks to Z80 SBC; they prompt for that directory.

Copying is one-way. Changes in SBC session disks do not automatically update the ESP32 base disks. ESP32 F5 debugging uses private snapshots; use its normal start task for persistent CP/M edits. See the ESP32 editing and copy guide.

In the Z80ROMlessSBC project

These steps target the completed Phase 10 hardware and firmware setup. When first bringing up Phase 9, use its USB CP/M and flash storage instructions and complete its tests before moving on to Phase 10.

  1. Open the Z80ROMlessSBC project folder in VS Code and run Run interactive CP/M emulator to use the copied disks. The launcher validates them and patches A with this checkout's CP/M, BDOS, BIOS and AUTORUN. B-D are copied unchanged. No import step is needed.
  2. For hardware deployment, use Build and flash Pico - Phase 10 firmware from the same checkout before flashing the matching CP/M disks and boot package. Firmware-only deployment preserves storage.
  3. Choose Terminal → Run Task and one of the disk deployment tasks below. All tasks use src/disks/native/, the same source as the emulator. The all-disks task validates A-D and rebuilds A plus the matching boot package. Follow the deployment requirements.
  4. With both the disks and Pico firmware deployed, boot CP/M on the real Z80 and access the installed applications on the configured drives A: through D:.

The Pico serves the flash-backed disks while the Z80 executes CP/M and its applications. See the disk provisioning details for how this works. The firmware uses native 524,288-byte images.

VS Code disk deployment tasks

The tasks in .vscode/tasks.json use src/disks/native/ for all-disk and individual-drive deployment:

Task Disks replaced Source image
Flash Pico - All disks (A-D) A: through D: A-D from src/disks/native/; A's system tracks rebuilt
Flash Pico - Drive A A: drive_a_cpm63k.img (system tracks rebuilt)
Flash Pico - Drive B B: drive_b_bdsc.img
Flash Pico - Drive C C: drive_c_escape.img
Flash Pico - Drive D D: drive_d_blank.img

With both emulators stopped, copy updated images into src/disks/native/ using the filenames above. The A: tasks regenerate the board-native boot disk; the B:–D: tasks flash the selected prepared images with unchanged B-D contents. Every disk task validates source and prepared filesystems before deployment. The tasks replace selected disks without backups and preserve firmware and ENV settings. All disks (A-D) also validates and installs the newly built boot package with Drive A. Individual drive tasks preserve the installed boot package; Drive A checks compatibility. Follow the task's confirmation prompt before deployment.

Drive A: also contains the boot system and needs the board-native BIOS and matching boot package. Drives B: through D: can hold application disks copied from the ESP32 project. See Phase 9: USB CP/M and flash storage for the storage design and the disk media README for validation commands and the shared source-image mapping.