Changes
* Its first 512 Kbyte are compatible with external memory expansions (Dk'tronics, Inicron RAM expansion, SYMBiFACE II etc.), using port #7Fxx (see [[Standard Memory Expansions]]).
* Its first 2 MB are compatible to RAM7's 2 MB expansion.
* The whole 4 MB can be used trough ports #78xx to #7Fxx (see [https://web.archive.org/web/20120215003307/http://8bit.yarek.pl/upgrade/cpc.cpc4mb/index.html CPC4MB] Page, for futher further details).
* the expansion connects to the PAL inside the 6128.
* all configuration codes are supported (0-7) and work exactly as they do in a 6128.
* I/O port decoding is: 0xxxxbbbxxxxxxxx (confirmed by TFM) where bbb are 3 bits of the bank. The other 3 bits are from the data decoded as 11bbbccc and ccc the configuration code. Yarek's site recommends that bits A14,A13,A12,A10 A11 are set to 1 to avoid conflict with other hardware.
== Software ==
* [[A Tribute to the Sisters|Giana Sisters Remake]]
* [[Captain Future|Captain Future Video Demo]]
* The first MB of the 4 MB expansion (&7Fxx, &7Exx) is supported by [[SymbOS]] version 2, but buggy.
== Schematics ==
== Links ==
* [httphttps://8bitweb.yarekarchive.plorg/upgradeweb/cpc.cpc4mb20120215003307/index.html CPC4MB]* [http://8bit.yarek.pl/upgrade/cpc.cpc4mb/cpc4mb1index.zip PCB Layouts in Eagle formathtml CPC4MB](mirror on Archive.org)
See also the [[:Category:Memory expansions|list of memory expansions for the CPC]]
[[Category:4 MB RAM Software Support]] [[Category:DIY]] [[Category:FutureOS]] [[Category:Hardware]] [[Category:Memory expansions]] [[Category:Peripherals]]
