Simple Atari ST Project Template

This is a simple project template for assembly programming projects for cross-developing for the Atari ST. You'll need make, vasm, and vlink installed for it to work. Check your distribution's package manager.

The example code in this repository loads a palette into VDP and displays a simple sprite. Then it enters an endless loop.

I prefer to assemble files into object files first and link them into an executable/ROM in a separate step. So the Makefile in this repository uses both the vasm assembler and vlink linker.

Usage

Use git to clone this repository:

git clone https://github.com/georgjz/atari-st-project-template
cd atari-st-project-template
make

The makefile will look for all source files ending with *.s in the directory src/ and all its subdirectories. Include files ending with *.inc will automatically added to the assembler arguments with -I. These files are translated into object files and listings will be placed in the directory obj/. Finally, the linker will build the final executable and place it in build/.

Switching between Syntax Standards

I prefer vasm's Motorola Syntax; if you wish to use another syntax, you'll need to modify line 20 in the Makefile.

WARNING: Switching to another syntax/assembler might break the example code given here.

Example Code

There's two source files in src/:

• init.s contains the code that GEMDOS requires the program to execute. It will calculate its own size, and uses Mshrink to shrink the TPA to the correct size. It then jumps to the Main routine.
• main.s contains the Main routine. It switches to supervisor mode. Then it waits for the space key to be pressed. Once space it pressed, it calls Pterm to exit the program and return to TOS. It also contains the bss definition for the user stack.

License

All code in this repository is under the MIT license.