4 MB DRAM internal memory expansion for CPC.
* It's first 512 Kbyte are compatible with external memory expansions (Dk'tronics, Inicron RAM-BOXexpansion, SYMBiFACE II etc.), using port #7Fxx (see [[Standard Memory Expansions]]).
* It's first 2 MB are compatible to RAM7's 2 MB expansion.
* The whole 4 MB can be used trough ports #78xx to #7Fxx (see [http://8bit.yarek.pl/upgrade/cpc.cpc4mb/index.html CPC4MB] Page, for futher details).