Newsgroup

comp.sys.ibm.ps2.hardware (Google Groups) USENET newsgroup dedicated to PS/2 systems, even the non-MCA ones. It is inhabited mainly by people who are enthusiasts, obsessives, M.A.D. or all three! Take a look at it.

Ardent Tool Mirrors

Kevin Bowling's Mirror This is the real deal. Maintained by Louis Ohland himself! [US]
Vampire's Mirror Earlier snapshot [IT]
Bob Eager's Mirror Very old snapshot [UK]
Wild Bill's Mirror Very old snapshot, modified Home Page [US]

PS/2 and MCA Related Fan Sites

The Microchannel Enthusiast's Page by Peter Wendt (old address)
(info from mcamafia.de merged to this version of The Tool)
MCA Base (by Unal Z) (local #1, local #2)
Walsh Computer Technology Computer Collection Pages by William Walsh
Just Another Freekin' Web Page by Jim Shorney. (old address)
   The P70 Project by "Dr" Jim Shorney (God of Solder!) (old address) (local version)
Personal System/55 (JP) Tatsuo Sunagawa (local version)
The PS/2 Page by Dennis Smith. Contains sorted links down to IBM minotaurian ftp-labyrinth of reference, diagnostic and option disks (old address)
Tavi PS/2 Pages by Bob Eager; Get his IDMCA there.
   If you have Reply Upgrade, check Files for Reply hardware
Model 80 Page by Kane Partridge from Australia
The MCA Mafia is coming for you from Smokey Behr
Alfred Arnold's website
The PS2 Resource Center from Computercraft
NetBSD on a PS/2

Official Websites

IBM - Official Links

IBM Announcement Search (enable JS, as of 17 June 2016) (old address)
IBM Networking FTP (?) site, may need to surf IA for links
IBM Boulder FTP
IBM Software FTP
IBM Hursley (P2P) FTP (pretty much empty)

IBM - Mirrors

IBM PCCBBS FTP server
EPRM mirror (different version)