This is just a simple collection of links to stuff of interest to budding Atari 7800 Programmers. It is not complete, or even in any useful order yet.

Mitchell Orman's The Atari 7800 Page
lots of 7800 stuff including ROMs and manuals, and Documentation & Errata from the original Atari 7800 development system.

John Saeger's Atari Documentation Depot
Good source for Atari 2600 and Atari 7800 technical documents including the 2600 and 7800 Programmer's Guides

AtariAge
message boards for programmers and collectors/enthusiast and much much more

Dan Boris's Atari 7800 Tech Page
author of the V7800 emulator, downloads of a78sign and some source code

The Official MESS Home Page Multiple Emulator Super System, emulates many consoles & computers (including the Atari 7800) on multiple platorms (Win32 & Unix source current, others backlevel)

OnLine Atari History Library and Web Resource
Lots of usefull stuff in the downloads section

The Atari 7800 Developer's Page
This site contains information on how to build your own Atari 7800 development system and how to work around the encryption key to make home-brew cartridges.

Jindroush's 7800 Tech Page
Hardware information, and a disassembler elsewhere on the site.

Eckhard Stolberg's VCS workshop
This site contains information on how to build your own Atari 7800 development system and how to work around the encryption key to make home-brew cartridges.

The Atari History Museum
Lots of documentation and articles

The Anarchistic Atari Page
This site has (among other things) a copy of the Atari 2600/7800 development system disks for the Atari ST, but there is some useful stuff in the devkit even if you don't have an ST.

Oliver Scholz's 7800 page
Contains information on a couple system and cartridge modificaitons.

Lee Krueger's Atari 7800 Page
Instructions on how to do a composite video mod on a 7800 and how to add a B/W switch to the system

Saundby's Atari 7800 Mods
Another video mod