Sinclair ZX-81 back from the dead
- Tony Smith writes about the availability of ZX81 DIY kits.
- http://www.theregister.co.uk/2000/10/10/sinclair_zx81_back/

ZX81Kit .Com
- A European supplier of the Sinclair ZX81 computer in kit form. Also contains useful information and links, and other ZX81 hardware is available.
- http://www.zx81kit.com/

ZX81 kit
- UK based sales and support of ZX81 computers in kit form, also related peripherals and books.
- http://www.zx81kit.co.uk

Sinclair ZX81 Collection
- Collection of original Sinclair ZX81 hardware, software and literature. Photos and description for each item.
- http://zx81.atspace.com

ZX81 Forever
- Pictures, newsletters and programs made with the ZX81, a 16kb rampack and a Timex 2040 printer. Updated monthly.
- http://www.zx-team.de/andre

ZX80 hardware page
- How to build your own ZX80 and ZX81.
- http://home.micros.users.btopenworld.com/zx80/zx80.html

ZX81 'Caverns' Game - PC Remake
- Author of the original 1980's 'Caverns' game offers a PC remake for download. Includes game history and instructions.
- http://www.users.globalnet.co.uk/~mart03/zx81.htm

Obsolete Computer Museum's ZX-81 Page
- Technical specifications and pictures of the Sinclair ZX81 with comments from other ZX81 owners.
- http://www.obsoletecomputermuseum.org/zx81/

Sinclair ZX81 FAQ
- Some common questions about the ZX81.
- http://www.honneamise.u-net.com/zx81/zx81faq.html

Rodney Knaap: Build your own ZX81
- ZX81 hardware website featuring a project for building your own ZX81 with discrete components as well as Wilf Rigter's ZX97. In English, Dutch and German.
- http://www.angelfire.com/ab6/rodneyknaap/

Sinclair ZX81 Benchtest
- Article from Personal Computer World by David Tebbutt.
- http://www.nvg.ntnu.no/sinclair/computers/zx81/zx81_pcw0681.htm

ZX81 - Planet Sinclair
- Information, photos and resources for the Sinclair ZX80, including a detailed account of its development extracted from Ian Adamson and Richard Kennedy's book "Sinclair and the Sunrise Technology".
- http://www.nvg.org/sinclair/computers/zx81/zx81.htm

Zebra Systems, Inc.
- Timex-Sinclair ZX81 computer kits for sale.
- http://www.zebrasystems.com/zebrasystems/zx81/index.html

ZX81 Home Page
- A ZX81 FAQ, emulator and software links.
- http://www.honneamise.u-net.com/zx81/

ZX-TEAM
- An active German Sinclair ZX81 users' group. Site offers information about the Sinclair machines and the group's activities, including news of forthcoming events, nn English and German.
- http://www.zx81.de/

System Variables of the Sinclair ZX81
- Memory map of the RAM reserved by the system.
- http://www.penelope.demon.co.uk/zx81/sysvars.html

ZX81 Download Page
- A ZX81 software archive.
- http://www.zx81.nl