The Atari XL series of computers which quickly replaced the Atari 1200XL initially consisted of the Atari 600XL and 800XL were released in 1983.    Two other systems were slated for release in early 1984 which were the Atari 1400XL and Atari 1450XLD.   However the Atari 1400XL would never see the light of day.   It had been slated to be cancelled within the company and finished for research purposes only.   The Atari 1450XLD was supposed to be released around the summer to fall of 1984 and it too would never been released because of the sale of Atari, inc. to the Tramiel family.   The entire XL line of computers were cancelled to be replaced by the XE line of computers instead.   Other XL systems were mentioned but in one way or another never made it past the drawing boards and wire wrapping stages.  The Atari 1650XLD was rumoured to be an MS-DOS clone system in an Atari 1450XLD case, also an Atari 800XLD was talked about but never produced (it would have been an 800XL with "Freddie" MMU and disk drive in an Atari 1450XLD case) and the final XL was to be the Atari 1850XL which was to be the Atari version of the licensed Amiga technology.   (In September of 1983 Atari and Amiga signed into a contractual agreement that Atari would fund Amiga $500,000 to complete the development of the Amiga chipset.   Atari would get exclusive rights to use the chipset under the Atari name for a new high-end game console.   After one year, Atari could then sell a keyboard upgrade for the game console, plus utilitize the technology in a new series of Atari computer systems).

On June 30, 1984 Amiga was set to deliver the chipset to Atari but backed out, instead it had negotiated with Commodore to repay the loan back to Atari that Amiga had borrowed to develop the Amiga chipset and Commodore bought Amiga.   Atari was never able to produce both its 1850XL computer and also its new high-end video game console which were both to be based on the Amiga chipset technology.   On August 13, 1984 Atari filed suit against Amiga for breach of contract and use of technology that Atari had paid to be developed.   The suit was settled in 1987, however it was a closed decision and although rumours leaked that Atari won the suit, no positive confirmation of this has been found to date.

The electronics design of the Atari XL series of computers were done in the New York WCI Atari research labs under Steve Mayer with Gregg Squires as the head of Engineering.   Meanwhile in Atari's Sunnyvale offices in the Industrial Design group headed by Roy Nishi, Regan Cheng designed the all new look for Atari's second generation of computers.   Going for a very attractive high-tech look based on similarities to equipment made by Bang & Olufsen.    Regan Cheng designed an all-new look into what became the first Atari XL computer, the Atari 1200XL.    It can probably be labelled the world's first stylish and sexy looking computer system.     The XL series of off-white/dark brown, low profile, high tech looking systems was born.