View source for CPC4MB

[[image:Cpc4mb3.jpg|right|thumb|4MB expansion kit]]
== Description ==

4 MB DRAM internal memory expansion for CPC6128. 

* 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 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,A11 are set to 1 to avoid conflict with other hardware.
* accessing the upper 2MB of a 4MB expansion requires special caution to avoid conflict with other hardware expansions. See [[Standard Memory Expansions]] for details.

== Software ==

* Currently, CPC4MB is supported by [[FutureOS]] version .8 or higher
* The 4 MB E-RAM Test: [[Media:E-RAM_Test_2014.zip]]
* [[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]].

== Schematics ==

Schematics have vanished together with the CPC4MB website and unfortunately have not been archived anywhere else.

== Links ==
* [https://web.archive.org/web/20120215003307/http://8bit.yarek.pl/upgrade/cpc.cpc4mb/index.html 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]]