C Programming

Current C applications use the host-based dcc compiler for CP/M 2.2 on the Z80 alongside Assembly and BASIC applications.

dcc supports C89 plus CP/M-relevant C99/C11 features. It runs on Windows, macOS and Linux, producing M80 assembly that is assembled and linked into a CP/M .COM application.

Start with dcc's toolchain setup and build/link reference. The target has 16-bit int/pointers and 32-bit long; use dcc's runtime documentation rather than assuming desktop C library behavior.

Build applications

Install PowerShell 7, dcc/ntvcm and cpmtools (cpmrm and cpmcp). Then use the app's build-app.ps1, or the aggregate build:

pwsh ./Apps/BUILDALL/build-all.ps1

Stop the emulator before installing into its disk image. For build-only validation, run dccmake in the app directory instead. See Build and Install CP/M Apps for tool checks, installation and disk format details.

Shared service client

Applications use Apps/COMMON/DXSVC.C and DXSVC.H for ROMless shared services. Terminal/disk BIOS interfaces are unchanged. Do not use the removed legacy service port numbers.

For an app directory under Apps/, a minimal example is:

#include <stdio.h>
#include "../COMMON/DXSVC.H"

int main(void)
{
    char version[128];
    if (svc_get_text(SERVICE_GROUP_UTILITY, 3, version, sizeof(version)) < 0)
        return 1;
    printf("Emulator: %s\n", version);
    return 0;
}

Compile the shared implementation as a separate input, as the current app configurations do:

dcc-input=hello.c,../COMMON/DXSVC.C
dcc-output=HELLO
dcc-include-directory=${DCC_DIR},../COMMON
dcc-stack-bytes=768

The shared client reference documents framing, return/error conventions and regression tests.

See Editing Files for source editing, file transfer and the retained CP/M assembly workflow.