Lemmings, the complete manual added to openretro.org and here.
The Anatomy of the 1541 Disk Drive
The Micro Enquirer Commodore 64, again many thanks to John Watson.
Amiga ROM Kernel Reference Manual: Libraries and Devices, thanks to DDHF.
GEOS Tips & Tricks from Abacus, another great donation from John Watson.
GEOS Inside and Out, donated by John Watson, thanks a lot.