* [[Dk'tronics memory expansion|Dk'tronics Memory Expansion and Silicon Disc]] - 64K and 256K expansions
* [[Dobbertin Memory Expansion]]
* [[CPC4MB]] (DIY) - compatible with standard 512 Kbyte expansion (plus extra nonextended-standard 3.5 MBbyte)
* [[RAM BOX]] 512Kb memory expansion '''(is that lowercase "b" meaning 512kbit=64Kbyte ???)'''
* [[SYMBiFACE II]] - includes (among others) 512K RAM expansion