This is a simple Atari (VCS) 2600 framework based on the cc65 compiler (and ca65 assembler). It allows developing demos or applications for the Atari 2600 by mixing C and assembly code.

Prerequisite

• Linux (any distribution should do)
• cc65 is required to compile the code.
• Stella is required to run the generated binary

Installing cc65

$ git clone https://github.com/cc65/cc65.git
$ cd cc65
$ make
$ prefix=${HOME} make install
$ echo "export CC65_HOME=${HOME}/share/cc65" >> ~/.bashrc

Installing Stella

Stella is packaged by most Linux distributions (Tested with Fedora and Ubuntu). Otherwise, it can be downloaded from Stella website

Compiling & Running your code

$ make  # This compiles the code with cc65 and generated main.bin
$ make run  # Runs main.bin in Stella

Writing a VCS demo / app

There are mainly 2 files that need to be updated:

• c/main.c contains the main loop and the inter-frame logic (for instance updating some useful variables).

• asm/kernal.s contains what is called the "kernal" (or kernel) in the Atari 2600 terminology. It is the code that is responsible for drawing a single frame. It is called 50 times per second for a PAL setup (60 times per second for NTSC).

Other resources

• Stella programmer's Guide
• cc65 Documentation
• 6502 instructions set