7800 Tutorials and Guides
Atari 7800 Color Documentation covers how the 7800 generates its colors, with specific consideration to color selection for homebrew authors.
Maximizing 7800 Sprites discusses techniques that can be used for games that need a maximum number of moving objects.
Eckhard Stoiberg's TIA Frequency and Waveform Guide covers TIA musical frequencies.
The Perceptual Tuning Primer covers an easy technique to keep TIA music sounding in tune.
The Tune2600 Introduction covers using the tune2600 utility to select your notes.
TIA Arpeggiator Tips provides helpful information for implementing arpeggiator effects in your music.
External Hardware Documents
Atari's internal POKEY C012294 Documentation covers POKEY in a formal manner.
AtariVox for the 7800 covers details for accessing the AtariVox peripheral.
The HSC Layout describes the NVRAM layout for the HSC Cart.
A78 Header Specification covers the purpose and various fields in the A78 header.
6502 Beginner Tips contains useful information and references if you're new to 6502 assembly.
6502 Advanced Tips contains information for seasoned 6502 coders.