CNet 5 SDK for GCC

A modernized SDK for developing doors, PFiles, and utilities for the CNet Amiga BBS system, targeting the m68k-amigaos-gcc cross-compiler.

The original CNet 5 SDK was written for SAS/C on native AmigaOS. This project ports the headers, library stubs, linker library, and examples to compile cleanly under the Bebbo GCC cross-compiler toolchain, making it possible to develop CNet doors from a modern Linux or macOS workstation.

Who Is This For?

• CNet BBS sysops who want to write or modify doors and utilities
• Retro-computing enthusiasts exploring the Amiga BBS scene
• Door developers building new PFiles for CNet 5 systems

Why GCC?

The original SDK required SAS/C, a commercial compiler that ran natively on AmigaOS. The Bebbo GCC toolchain offers several advantages for modern development:

• Cross-compilation from Linux, macOS, or WSL -- no Amiga hardware needed for compilation
• Modern tooling -- use your preferred editor, debugger, and version control
• Free and open source -- no commercial compiler license required
• Active maintenance -- the Bebbo toolchain is actively maintained and supports modern AmigaOS NDK headers
• CI/CD friendly -- automated builds are straightforward on any Linux host

The trade-off is the __asm compatibility issue documented in known-issues.md -- a minor include-ordering constraint that the templates and examples already handle.

Quick Start

git clone https://github.com/tbdye/cnet-sdk.git cnet-sdk
cd cnet-sdk
make lib        # build libcnet_door.a
make examples   # build all example programs

See docs/getting-started.md for a complete walkthrough of writing, compiling, deploying, and testing your first PFile.

Build Requirements

• m68k-amigaos-gcc (Bebbo GCC toolchain) installed at /opt/amiga/ (override with make PREFIX=/your/path)
• GNU Make
• A CNet 5 BBS (v5.x) running on a real or emulated Amiga for testing
• amigactl (optional) -- Remote Amiga management tool, useful for deploying compiled binaries

Editor Support

The SDK includes VS Code workspace configuration for a batteries-included development experience:

• IntelliSense -- code completion, hover documentation, and error checking for CNet and AmigaOS APIs
• Build tasks -- Ctrl+Shift+B compiles with errors linked to source locations in the Problems panel
• Code snippets -- cnet-door and cnet-standalone scaffolds, plus common API patterns

This works on native Linux and Windows (via WSL) with zero configuration changes. See docs/vscode-setup.md for setup instructions, including a complete Windows/WSL walkthrough.

SDK Contents

Libraries

Library	Description
lib/libcnet_door.a	Static linker library: door lifecycle, CNC_* wrappers, utility functions

Five CNet shared libraries are accessed at runtime via inline stubs (not included in this repo -- they are part of the CNet BBS installation):

Library	Functions	Purpose
cnet.library	79	System services (subboards, accounts, files, semaphores)
cnetc.library	66	Door I/O and BBS services (text, input, editor, protocols)
cnet4.library	15	Date/time and range utilities
cnetmail.library	14	MIME and mail routing
cnetgui.library	2	GUI support

Headers

• include/cnet/ -- CNet struct definitions (PortData, MainPort, UserData, etc.)
• include/clib/ -- C prototypes for all CNet library functions
• include/fd/ -- Function definition files (register assignments)
• include/inline/ -- GCC inline stubs (generated from FD files)
• include/pragma/ -- SAS/C pragmas (for reference; GCC uses inline stubs)
• include/proto/ -- Proto headers that pull in the correct stubs

Examples

42 example programs demonstrating CNet API usage:

• CNetC doors (the modern door framework)
• Standalone utilities (read BBS state without a login session)
• Raw CMessage doors (v3-style compatibility)

Templates

Three starter templates for new projects:

Template	Use Case
templates/pfile_cnetc.c	CNetC door with full wrapper function list
templates/pfile_raw.c	Raw CMessage door (v3 compatible)
templates/standalone.c	CLI utility accessing CNet data structures

Documentation

Document	Description
getting-started.md	First PFile walkthrough
architecture.md	CNet process model and data structures
library-reference.md	All 176 library functions
structures.md	Struct field reference
pfile-guide.md	Door development guide
examples-guide.md	Annotated example catalog
migration-v3-to-v5.md	Porting v3 doors to v5
arexx.md	ARexx interface reference
vscode-setup.md	VS Code and Windows/WSL setup guide
known-issues.md	Known issues and errata
version_delta.md	v5.01 vs v5.36c ABI comparison

Tools

Tool	Purpose
tools/libinfo	Display CNet library version and export info
tools/structsizes	Report sizeof() for all CNet structs
tools/guoffset	Verify GetUsers field offsets

Compatibility

Tested against CNet v5.36c running under Amiberry. The library ABI is unchanged between v5.01 (SDK release) and v5.36c, so doors compiled with this SDK work on any CNet v5.x installation.

All 53 programs (42 examples, 3 templates, 3 tools, 5 tests) compile with zero errors. Standalone utilities have been verified on a live system. See docs/version_delta.md for ABI details.

Credits

CNet BBS was originally created by Ken Pletzer under Perspective Software. Development was continued by Ray Akey and Todd Knight under ZenMetal Software, with Ray Akey serving as the primary developer from v4.x onward. Kelly Cochran contributed to the cnetc.library and SDK examples. CNet is currently maintained by Dan FitzGerald.

The original v5.01 SDK was distributed as part of cnet5demo.lha on Aminet.

GCC porting, documentation, and tooling by Thomas Dye.

License

Original CNet SDK materials are redistributed under their original terms (see headers for per-file copyright notices). New work (GCC porting code, documentation, build system, tools, tests) is licensed under the MIT License.