I'm trying to collaborate in the preservation of the zx81 related material.
Well I buy some time ago, a lot of books and mags about zx81. Living on Argentina on the 1984 makes very hard to find magazines or books about this topic... so I do discover all the printed material years latter
I have a small Brochure that I never saw in digital form and then I scanned in order to share it with other zx81 users and collectors.

http://pp.bytemaniacos.com/SinclairZX81SoftwareCatalogue.pdf
Gus
