Section credits: Jerry Jessop, Scott Emmons, http://www.digitpress.com/,
http://www.atarimuseum.com/
Special thanks: Mr. Doug Neubauer (via James Finnegan); Mr. Gregg Squires

Atari 400/800 ("Colleen") hardware engineers:
Steven T. Mayer     - early system design, overall plan
Joseph C. Decuir    - ANTIC logic design, early system design, overall plan
Jay G. Miner        - System architect (became manager of development of both
                      VLSI custom chips and OS software), overall plan
Douglas G. Neubauer - POKEY logic design (also wrote: Star Raiders)
George McLeod       - CTIA/GTIA logic design
Ronald E. Milner    - early system design
Francois Michel     - ANTIC design
Mark Shieu          - POKEY chip design
Steve Stone         - POKEY layout design
Steve Smith         - Technician for ANTIC and GTIA
Delwin Pearson      - Technician for POKEY
Kevin McKinsey      - 400/800 case design

Atari 400/800 Operating System software engineers:
David Crane         - OS design, programming
Larry Kaplan        - OS design, programming
                      (also wrote: Video Easel, Super Breakout)
Alan Miller         - OS design, programming (also wrote: Basketball)
Harry B. Stewart    - consultant, OS design
Gary Palmer         - worked on the I/O portion
Ian Shepard         - disk drive functions
Michael P. Mahar    - Revision B fixes
R. Scott Scheiman   - Revision B fixes

Atari 1200XL (Sweet-16/"Elizabeth"/"Liz") computer hardware engineers:
(Atari NY Lab, then W.C.I. Labs, 300 E 42nd St, New York NY)
Steven T. Mayer     - Head of NY Lab, then Chairman and CEO, WCI Labs, Inc.
Gregg Squires       - Project Manager (previously of Racal-Vikonics)
Robert (Bob) Card   - Principal Engineer (previously of Racal-Vikonics)
Steven Ray          - Critical Electronics Layout Designer
                      (previously of Racal-Vikonics)
Joel Moskowitz      - Mechanical Engineer
Philippe des Rioux  - project engineer
Glenn Boles         - project engineer 
Henry Dreyfuss Associates - Early case design concepts
Risa Rosenberg      - Secretary to Gregg Squires

Atari 1200XL computer hardware engineers: (California)
Regan Cheng         - XL case design

Atari 1200XL Operating System ("Z800" revs 10, 11) software engineers:
Harry B. Stewart    - External Reference Specification
Lane Winner         - ?
R. Scott Scheiman   - Handler Loader
Y. M. (Amy) Chen    - Relocating Loader; International Character Set
Mike W. Colburn     - Self Test
Richard K. Nordin   - ?

Atari 600XL/800XL ("Surely"/"Surely Plus") computer hardware engineers:
?                   - ?
Regan Cheng         - XL case design
?                   - FREDDIE
?                   - FGTIA

Atari 600XL/800XL Operating System ("Surely OS" Revs 1, 2) software engineers:
R. Scott Scheiman   \
Richard K. Nordin   --- Support PBI and on-board BASIC
Y. M. (Amy) Chen    /

Atari Corp. 800XL and XE systems hardware engineers:
Jose A. Valdes      - (at Atari from October 1979 - August 1989)
Ira Velinsky        - designer of the XE game system

Atari Corp. XE Operating System (Revisions 3, 3B, 4) software engineers:
?                   - ?