6502.org: The 6502 Microprocessor Resource.
68kMLA: All good macs get liberated.
AmigaLove: Your Amiga and Commodore Computer Retro Home. AmigaLove is a friendly and knowledgeable community with a growing Games Library for fans like you!
Amiga Retro Brisbane: Welcome to Amiga Retro Brisbane, we are an (Australian) based community of Commodore Amiga users, gamers and lovers of all things retro technology.
Atari Forums: Atari Arcade Games, 2600, 5200, 7800, Lynx, Jaguar & Forums.
AtariAge: AtariAge is dedicated to bringing you the latest Atari news, providing support for the Atari community, and maintaining an extensive historical archive.
c64scene.pl (POL): Forum polskiej sceny C64.
Commodore Remix Forum: C64 and Amiga Music Remix Community.
CSDb User Forums: The Commodore 64 Scene Database.
IRATA ONLINE: A PLATO Service for Retro Computing Enthusiasts. IRATA.ONLINE is provided for the benefit of retro-computing users to have a place to socialize, and develop interesting multi-user, interactive, and graphical games and social applications. It descends from the historical PLATO system, a massive time-sharing system that lasted from 1962 until NovaNET was closed in 2015.
IRIX Network Forums: The IRIX Network is the world's premiere Silicon Graphics hobbyist community.
Lemon Amiga: Lemon Amiga Forum.
Lemon64: Lemon64 Commodore 64 Forum.
Melon64: Commodore 64 (C64) forums.
Murray² Forum: The 8-Bit Guy and The Geek Pub Combined Forum.
OldGamesItalia (ITA): The Italian Oldgamers Community since 2002.
OS2World: Welcome to OS2World, the Internet's premier community resource for OS/2, eComStation and ArcaOS (all OS/2 Warp flavors) news. OS2World delivers updated news about OS/2, eComStation and ArcaOS and related hard-hitting articles and reports to IT professionals and technology innovators.
Ready64 Forum (ITA)
Retro Computing - Minicomputers, Micros, and More: Here we share stories and information about retrocomputing and vintage computers, from cogwheels or relays through transistors and chips, from experimental machines through mainframes to 8-bit and 16-bit home computers. This is a museum of all things computational: mechanical, mainframe, mini, micro. We love interesting posts about software and hardware, about computers or calculators you’ve made or fixed or owned - or things you found on the web or in books and magazines. Or your own recollections or observations. Keep it interesting, and be nice to each other!
RetroBrew Computers Forum: Discussion forum for the RetroBrew Computers community.
Retrocomputing Stack Exchange: Retrocomputing Stack Exchange is a question and answer site for vintage-computer hobbyists interested in restoring, preserving, and using the classic computer and gaming systems of yesteryear.
Silicium (FRA): Discussions sur les vieux ordinateurs, pockets & consoles.
Silicon Graphics User Group: Community, chat, info, and software for Silicon Graphics enthusiasts.
Sinclair ZX80 / ZX81 Forums: Discussion forums for users of the Sinclair ZX80 / ZX81 and their clones.
SMS Power!: Active since 1997, we are an international force of enthusiasts interested in the following gaming/computer systems: Sega Master System (SMS) / Sega Mark III (MK3), Sega Game Gear (GG), Sega Game 1000 (SG-1000), Sega Computer 3000 (SC-3000), Sega Super Control Station (SF-7000), Othello Multivision (OMV) (SG-1000 clone). And their regional variants (Korean Samsung Gam*Boy, Taiwanese Aaronix consoles, etc.). All generally referred to as “Sega 8-bit” systems, being 8-bit Z80 CPU based Sega systems.
stardot.org.uk: Community site for Acorn Computers: Atom, BBC Micro, Electron and Archimedes.
The Sinclair QL Forum: The Home of Everything QL!
Vintage Computer Forum: Vintage Computer Federation is a user group for people who collect and restore historic computers. We’re a 501©3 non-profit. We evolved in autumn 2015 from the DNA of related groups.
Vogons: Very old games on new systems.
VzEkC e. V.: Vintage computing forum of the German “VzEkC e.V” - a club dedicated to the preservation of old computers. Most topics are in German language, but you can write in English as well. Many users here are capable of reading and writing in English, so you can try :)