Allegro 4.2.3.1 (DJGPP/DOS cross compiling)

A fork of the old Allegro 4.2.3.1 release from October 2009, with a few minor modifications to the source to facilitate cross compiling with DJGPP.

This fork exists so that you can use Allegro to write DOS games with a version of DJGPP for a non-DOS, non-Windows system. If you don't intend specifically to build DOS games, you should use the latest release instead!

Originally, this version of Allegro was intended to be used with GCC 2.91.N. Some modifications have been made to make it work with GCC 5.2.0 as provided by DJGPP, and has been tested as high as DJGPP's GCC 12.2.0.

If you must compile this for a target other than DJGPP, you must edit /include/allegro/platform/alplatf.h and add the correct platform setting.

NOTE: This is a fork (of a fork) of the development branch of user SuperJamie. This repository simply exists to provide a github runner to automatically build the library for DJGPP/GCC 12.1.0 (as used by the VSCode DOS-Dev extension).

Usage

The first step is to get a working DJGPP compiler, as per andrewwutw's build-djgpp instructions. This should work for Mac OS X, Linux and FreeBSD, and has been tested with Mac OS X and Linux. Please let me know if you can verify that this works for other OSes.

Compiling

Edit xmake.sh to set the correct path to your DJGPP install. Some examples are:

XC_PATH=/usr/local/djgpp/bin
XC_PATH="$HOME/bin/djgpp"

Run ./xmake.sh lib to compile the library. No standard make command will work.

If all goes well, a lib/djgpp/liballeg.a file will be generated that you can link with.

Targeting Windows

If you're targeting Windows, you should probably not use this. Just use MinGW instead. It should be easy to compile something that works on both Windows 10 and DOS.

Patches

Aside from the modifications for easier cross-compiling, the following changes were made:

#1 - Fix broken 8-bit Sound Blaster volume - this was a longstanding bug with the 4.2.2 source
#2 - Add -fgnu89-inline to asmdef.exe target to facilitate GCC 5+
Update from 4.2.2 to 4.2.3.1 by cherry-picking upstream v4.2.2..v4-2-3-1 commits

Example

There's an Allegro DOS example repository available with a small Hello World program.

Copyright

Allegro 4 is giftware licensed.

Modifications by Michiel Sikma and Jamie Bainbridge are public domain.

This repository was forked off the liballeg/allegro5 repository, with all commit history past 2007-07-22 removed.