Actually, more of the ZX Spectrum PDF emulation Bible
, but this would be too long a post title… Still, oh wise and cheap-ass retroheads, just click here
and you’ll get yourselves the brilliant 82 pages long PDF of the aptly (and rather eloquently) named The ZX Spectrum on your PC
. Brilliant, educating, handy, quite free and sporting a nice cover, this is as retro as an ebook can get.