Books

• Mapping the Atari by Ian Chadwick
• The XL/XE Memory Map by Ian Chadwick
• Book: Mapa pamięci ATARI XL/XE: Podstawowe procedury systemu operacyjnego by Wojciech Zientara
• Book: Mapa pamięci ATARI XL/XE: Procedury wejścia-wyjścia by Wojciech Zientara
• Book: Mapa pamięci ATARI XL/XE: Procedury interpretera Basica by Wojciech Zientara
• Assembly Language Programming for the Atari Computers by Mark Chasin
• Dial Group Books and instructions
• Atari 8-Bit Operating Systems - Source Listings by Tomasz Krasuski

References

• Graphics Modes
• ATASCII and Internal Character Codes
• Memory Map - partial

Archives

• Atari Mania PDF books
• Atari Archives On-line Books
• Atari Magazines Antic, Compute!, etc.
• Tajemnice Atari
• Fandal Archive of games and demos
• FTP Pigwa Index of PDF books
• FTP Pigwa Index of ATR files
• Atari Land Index of PDF books
• Mapy Maps of game levels
• MatoSimi Blog
• Atari Fonts

Source Code

• Atari Games Source Code
• Sources Pigwa Atari Source Code Archive: Demos, Programs, Games
• SourceForge ASAP - Another Slight Atari Player

Hardware

• Lotharek Sio2PC-USB

Programming

• MADS Assembler
• ca65 - macro assembler for the 6502, 65C02, and 65816 CPUs
• ca65 - wiki
• Adding and subtracting - an article in Polish
• Emulators, dev tools, etc.

Atari Scene

• AtariAge.com
• AtariOnline.pl
• Mad Team

6502

• 6502.org
• Beyond 8-bit Unsigned Comparisons
• Compare Instructions
• 6502 Opcodes

Hacks

• AtariAge River Raid Hacks