For the Sinclair ZX80 and ZX81 computers as well as their clones such as Timex-Sinclair 1000 and 1500.
Obsolete Computer Museum's ZX-81 Page
Technical specifications and pictures of the Sinclair ZX81 with comments from other ZX81 owners.
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.
An active German Sinclair ZX81 users' group. Site offers information about the Sinclair machines and the group's activities, including news of forthcoming events, in English and German.
ZX81 Download Page
A ZX81 software archive.
Small black box of computing desire
The BBC reminisces about the memory-efficient programming motivated by the 1k ZX81. (March 11, 2011)
Sinclair ZX-81 back from the dead
Tony Smith writes about the availability of ZX81 DIY kits. (October 06, 2000)