== Description ==
4 MB DRAM internal memory expansion for CPCCPC6128.
* It's Its first 512Kbyte 512 Kbyte are compatible with external memory expansions (Dk'tronics, Inicron RAM-BOXexpansion, SYMBiFACE II etc.), using port #7Fxx (see [[Standard Memory Expansions]]).* Additional 3Its first 2 MB are compatible to RAM7's 2 MB expansion.5MBbyte * The whole 4 MB can be used trough ports #78xx to #7Exx 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,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 .8or 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]] version 2.
== Schematics ==
Altrough CPC4MB can be ordered fully asembled (even Schematics have vanished together with mounting on a CPC board), there's still a download of PCB design on the CPC4MB page, if you want to DIYwebsite and unfortunately have not been archived anywhere else.
== 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:Hardware4 MB RAM Software Support]] [[Category:PeripheralsDIY]] [[Category:DIYFutureOS]] [[Category:Hardware]] [[Category:Memory expansions]] [[Category:Peripherals]]