Links to other Atari 8-bit resources which may be of interest:
AtariAge Atari 8-bit Computers Forum
Hiassoft (TurboFreezer, High Speed SIO driver)
The Montezuma (SIO2BT, RespeQt)
Peter Dell (Jac!: WUDSN IDE for Eclipse)
The Altirra Atari 8-bit Emulator by Avery Lee
Lotharek (vendor of U1MB, VBXE, SIDE2, Rapidus, Stereo POKEY and more)
AtariBits (home of the 1088XEL)
The Brewing Academy (1088XEL vendor)
The SymbOS Z80 Multitasking OS
Wilson Mines Co. (large collection of 6502-related information)
Jerzy Sobola (huge collection of Atari schematics)
AtariDude’s website (various Atari 8-bit articles)