There are 47 books with no duplicates.
$100 + $20 shipping (U.S.A. only) for all of them.
If you are near Harrisburg PA you can pick them up and save the shipping cost.
Any questions please ask.
Discussion forums for users of the Sinclair range of computers - ZX80, ZX81, ZX Spectrum, their clones and Cambridge Z88
About the ZX80 / ZX81