text and source code section
On this page you will find explanatory texts about things that I noticed
while programming the Atari VCS 2600 and the Atari VCS 7800. Also you will
find example binaries with their source code to illustrate some of the
things, that the texts describe. You will need Matt Dillon's DASM 2.12.04
assembler to compile those source codes. Please check out the sites mentioned
in the link section to find a copy of this
program for your operating system.
Currently there are not too many files in this section, but I plan to
eventually put up all the things that I have posted to the Stella mailing
list over the last couple of years. So, hopefully this page will grow soon.
Please come back again from time to time and have a look.
VCS.H and MARIA.H
These files define symbolic names for all the registers in the VCS 2600
and the VCS 7800 in MARIA mode. You will need to have them in the same
directory as the source code files from this page, when you try to assemble
This example source code demonstrates how you can use small parts of certain
existing 7800 games to make your own game pass the encrypted signature check in
the NTSC 7800 console. This is nessessary, if you want to be able to play
your homebrew games on an unmodified NTSC 7800 console. PAL consoles don't
check for an ecrypted signature. Since it technically still is illegal to
distribute ROM images of commercial games, no binary is included with this
frequency and waveform guide
This text describes how I think the audio part of the TIA works. It inlcudes
tables with frequencies and note values for all available sound-type and
frequency devider values. This might be usefull, when you want to create
melodies for your game.
7800 bankswitching guide
This text describes the different bankswitching types that were used in 7800
cartridges. Also it lists the bankswitching type for all known games.
RMT POKEY player test for 7800
This example program shows you how to use the POKEY player routine from
Radek Sterba's Raster Music Tracker. Radek kindly allowed me to use one
of his songs for this. The player routine was changed to work on a ROM
based system like the 7800, so it should be easily possible to use it
in 5200 programs too.
last modified 19.03.2003 -
© Copyright 2000 by Eckhard Stolberg (