Historical

Mechanical Aids to Calculation - History on the first automatic totalizer by Sir George Julius, mechanical aids to calculation - extracts of a paper presented to the Institution of Engineers Australia in 1920.
http://members.ozemail.com.au/~bconlon/calcaids.htm

The Computer Closet - Rescues classic microcomputers and video games from the junk heap.
http://www.computercloset.org/

Historical Computer Society - International user group for old computer enthusiasts "old computers" and/or "old enthusiasts. Dedicated to preserving older and classic computer hardware, software, and literature.
http://www.cyberstreet.com/hcs/hcs.htm

Ian's 'Naff Computer Pics Page' - A page with some pictures of Honeywell-Bull mainframes and mini's (DPS-6 and DPS-7)
http://web.ukonline.co.uk/ie.dunster/My%20Stuff/Computer_page.htm

Charles Babbage Institute - CBI is a research center dedicated to promoting the study of the history of computing and its impact on society, and preserving relevant documentation.
http://www.cbi.umn.edu/

Cosmac Elf - History of 1802-based computing and home of the TinyELF emulator for Palm OS handhelds. Documents, scans, message board.
http://homepage.mac.com/ruske/cosmacelf/

John Elliott - Dedicated to computers and/or operating systems which some might describe as obsolete.
http://www.seasip.demon.co.uk/

Video Genie System - A personal tribute to an early model PC.
http://home.online.no/~kr-lund/VGS.htm

The Oldskool PC Shrines - Honoring personal computing in the 1980s.
http://www.oldskool.org/shrines/

The Apollo Guidance Computer Project - The Apollo Guidance Computer (AGC) was developed to provide reliable real-time control for the Apollo spacecraft that carried US astronauts to the moon, 1969-1972. This site is devoted to documenting the machines, people and institutions that made this possible.
http://hrst.mit.edu/hrs/apollo/public/

PC - History - Devoted to the history of the PC, covers all types of personal computers from 1970 to present.
http://www.pc-history.org/

ICL 1900 Series Computers - Information about the ICL 1900 series mainframes from the 1970s, both hardware and software. The George (1S, 2, 3 and 4) series operating systems, Minimop and Maximop. Programming languages and other information.
http://www.fcs.eu.com/icl1900/index.html

Retro Computer Gallery - Collection of pictures of old computers, consoles, handhelds and magazines.
http://www.imarshall.karoo.net/

Computer History Association of California - Chac is a nonprofit corporation, who safeguards and organizes the history of electronic computing, not only in California, but nationally and internationally. They collect and archive hardware, software and documents.
http://www.chac.org/

Enigma Replica - Shows all processes involved Building a replica of the German M4 Naval Enigma.
http://www.enigma-replica.com

Blinkenlights Archaeological Institute - The Institute was established in 1997 to excavate, preserve, research, and present interesting and historically significant computing devices.
http://www.blinkenlights.com/

The Burroughs B-205 Computer - A mixture of science fiction and fact concerning the B205.
http://www.angelfire.com/scifi/B205/index.html

BESM-6 Nostalgia Page - Information about the late Soviet mainframe computer BESM-6, the last original was dismantled in 1995.
http://www.mailcom.com/besm6/

Largest Classic Computer Documentation Archive - Thousands of scanned classic computer documents.
http://www.bitsavers.org/pdf/Index.txt

MIXTEL - Site is dedicated to the first home computer that could be bought in the UK.
http://www.mixtel.pwp.blueyonder.co.uk/

The SWTPC Computer Documentation Repository - Documentation for the SWTPC computer line.
http://www.swtpc.com/