Local History Retro Computing  
Cambusnethan
Cambusnethan - Rev P Brown
GENERAL
Z80 - Rodney Zaks
Z80 - Lance Leventhan
6502 - Assembly Language Programming
6502 - For humans

ZX 80/81
ZX80 Operating Manual
Basic Programming Manual
Art of Programming the 1K ZX81
Art of Programming the 16K ZX81
Mastering Machine Code on your ZX80/81
                                                       ... Errata
Assembly Language on the ZX81
Complete ZX81 ROM Disassembly
H4TH

ZX Spectrum
Basic Programming Manual
Mastering Machine Code on your Spectrum
Complete Spectrum ROM Disassembly
Cracking the Code
Forth-83
Abersoft Microdrive Forth

BBC Model B
User Guide
Forth on the BBC
Acornsoft ISO Pascal

VIC 20
User Guide

CBM 64
User Guide
Peeks and Pokes
Tips and Tricks
Pascal 64

AMSTRAD CPC 464
User Guide
Service Manual