Upgrading a 16K Spectrum to 48K - Spectrum for Everyone
Sinclair ZX Spectrum turns 40 – Born's Tech and Windows World
Chips
ZX Spectrum 16K to 48K memory upgrade kit | ByteDelight.com
memory - What is causing the problem with the RAM in this (claimed) Spectrum 48k? - Retrocomputing Stack Exchange
Shared Memory Dump
ZX Spectrum - Wikipedia
ZX Spectrum Upper RAM Module - zx.zigg.net
Sinclair ZX Spectrum +2 RAM Repair / Composite Video Fix - YouTube
ZX Spectrum Recreation Goes Next Level with New Manuals and Pack-In Goodies - Hackster.io
Chips
Z80SRAM - RAM / Z80 CPU replacement module for ZX Spectrum | eBay
Repairing ZX Spectrum+ 48K – Ask Notes
Sinclair ZX Spectrum RAM Repair (Upper RAM) - YouTube
zx Spectrum 48K 128K diagnostic ROM RAM TEST | eBay
Sinclair ZX Spectrum - issue one logic board and optional 32k ram expansion Stock Photo - Alamy
ZX Spectrum 48K Shadow of the Unicorn RAM Pack - Etsy
Chips
R.A.M. Walkthrough, ZX Spectrum - YouTube
