Ram under Rom - a brief look into C64 memory — Dustlayer
Chips
Commodore 64 Memory Replacement Module type 2 - Etsy
Memory Repair Commodore 64 - Amedeo Valoroso
Commodore RAM expansion units - The Silicon Underground
commodore64crap | The C64's 40th Anniversary is nothing to celebrate! Explaining why the Commodore 64's BASIC V2 was crap and how some people managed to program the C64. | Page 15
C128 - All RAM shown as faulty - any ideas? : r/c64