It was 1979 when Atari, Inc. entered the home computer market with the
	introduction of the 800 and the 400 computer systems.  (The 400/800 models
	were first shown publicly in November 1978).  These MOS Technology
	6502-based systems run at a clock speed of 1.79 MHz, offering 256 colors
	displayable simultaneously, up to 320x192 graphics resolution and up to 40x24
	text resolution in 11 graphics modes and 5 text modes.  Video may be displayed
	either on a composite video monitor in the case of the 800, or on a
	standard television for both systems.  4 independent sound voices are
	available through the audio output of the television or monitor, each with
	a 3 1/2 octave range, plus there is a built-in speaker for key-click and
	other programmable sounds.  The 800 has a second cartridge port and a
	full-stroke keyboard, while the 400 has a single cartridge port and a
	membrane keyboard.  Each has 4 serial controller ports and an Atari Serial
	Input/Output port.  Originally, both the 400 and 800 were sold with 8K RAM,
	but later most 800's were sold with 48K and 400's with 16K.  Each
	includes the 10K Atari Operating System in ROM.
	      
	The introduction of the 1200XL in 1982 marks the single largest advance in
	the 8-bit Atari system.  The 1200XL runs most software and hardware designed
	for the 800 and 400, but now runs a slightly more advanced 6502C
	microprocessor, and includes a full 64K RAM.  The single cartridge and
	monitor ports remain, along with 2 controller ports.  In addition, the 1200XL
	includes 4 programmable Function keys and a Help key, built-in diagnostic
	and graphics demonstration programs, and probably the favorite keyboard of
	any 8-bit Atari computer.  Clicks previously outputted through the built-in
	speaker are now heard from the television or monitor's speaker.  The revised
	16K Operating System offers many new features, including an alternate
	International Character Set.
	      
	In 1983 Atari replaced the 1200XL/800/400 line-up with the new 800XL and
	600XL.  These new machines include most of the features of the 1200XL minus
	the Function keys and the demo program.  But now both the 800XL and 600XL
	have the Atari BASIC language built-in.  In addition, these two systems
	offer the Parallel Bus Interface, providing direct memory access to the
	heart of the computer.  The 800XL contains 64K RAM while the 600XL has 16K RAM.
	      
	The new Atari Corp. delivered on its promise to advance the 8-bit Atari
	system by replacing the 800XL/600XL with the new 130XE and 65XE in 1985.
	The 65XE is nearly identical to the 800XL in features, minus the PBI.
	The 130XE, however, offers 128K RAM, plus a few special new graphics
	capabilities.  In addition, the 130XE replaces the PBI port with the
	Enhanced Cartridge Interface, continuing the powerful feature of direct
	memory access.
	      
	In a change of marketing strategy, Atari introduced the new XE Game System
	in 1987.  Despite its label, the XEGS is a true 8-bit Atari computer system.
	It offers the convenience of a detachable keyboard and built-in Missile
	Command game, while offering 64K RAM and full compatibility with the 65XE.
	
	Atari Corp. officially dropped all remaining support of their 8-bit
	computer line on January 1, 1992. 
        
        
        Most of the technical information on these pages, including the above text,
        was taken from the Atari 8-Bit Computers FAQ maintained
        by Michael D. Current and others. Additional information was taken from various magazine articles, books,
        and from taking apart several Atari computers.
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