[[File:Iram640.jpeg|thumbnail]]
[[File:Iram640 builtin.jpeg|thumbnail]]
[[File:Iram640ramtest.jpeg|thumbnail]]
CPC [[File:Iram640.jpeg|thumbnail|iRAM is a series of open source, DIY friendly, internal RAM expansions /640 for the CPC 6128 (later hopefully also ]][[File:Iram1024.jpg|thumbnail|iRAM/1024 for the CPC 464 and /664).]]
The CPC iRAM is the first [[Standard_Memory_Expansions|standard]] compatible, internal plug & play RAM expansion sits series for the CPC range of computer and provides up to 1MB of expanded RAM. All variations are open source, DIY friendly and sit in the CPU socket with no further cabling and requires no additional soldering inside the CPC. == Compatibility == No incompatibilities have been reported so far for the 6128 version. The first revision of the 464 version has been found to be incompatible with the [[M4_Board|M4 Board]]. [https://github.com/etomuc/CPC464-iRAM1024/blob/main/README_rev1.md#modification-for-m4-incompatibility A patch has been published].
The first 512K of expansion RAM follow the [[Standard_Memory_Expansions#Standard_128K-512K_Expansions_.28dk.27tronics.2Fdobbertin-style.29|DK'Tronics addressing mode standard]], giving up to 576K of RAM to legacy software. More modern software that supports the [[Standard_Memory_Expansions#Extended_1M-4M_Expansions_.28RAM7.2FYarek-style.29|extended 1M-4M standard]] will be able to access all the provided RAM.
== released ==External memory expansions will be ignored once the iRAM is installed. This can be useful for external feature-expansions that also provide a RAM expansion and usually cannot be used in parallel with other (external) RAM expansions. A great use case is to put the ULIFAC in ROM board mode which replaces the full or parts of the ULIFACs RAM with ROM slots. Now with the iRAM installed the CPC still has access to the full RAM provided by the iRAM. If needed a disable switch can optionally be connected to disable the internal iRAM from outside the CPC without removing the iRAM.
== Available versions == === CPC 6128 - iRAM/640 === <gallery>Iram640.jpeg|iRAM/640Iram640 builtin.jpeg|iRAM/640 built-inIram640ramtest.jpeg|RAM Test</gallery>
* for CPC 6128 only
* perfectly fits into a CPC 6128, even with socketed ROM or RAM. In Schneider CPC 6128 the metal shielding needs to be removed or altered.
StatusRepository: Released - see https://github.com/etomuc/CPC6128_iRAM-640
== currently in development ==''Note: Meanwhile a commercial product is available at Lotharek.pl which also claims to offer 640K and is even smaller, not much larger than the CPU socket itself. However not much information can be found except for the shop.''
=== CPC 6128 - iRAM/1088 === <gallery>iRAM1088.jpg|iRAM/1088</gallery>
* for CPC 6128 only
* perfectly fits into a CPC 6128, even with socketed ROM or RAM. In Schneider CPC 6128 the metal shielding needs to be removed or altered.
StatusRepository: Finished, will be released in late 2025https://github.com/etomuc/CPC6128_iRAM-1088
=== CPC 464/664 - iRAM/1024 ===
* <gallery>iRAM1024.jpg|iRAM/1024 for CPC 464 and /664* offers two sockets for SRAMsiRAM1024symbos.jpg|SymbOS on CPC 464* upgrade to 576K (1 SRAM) or 640K</1024K (2 SRAMS)* first SRAM: Upgrade to 576K, following the DK'Tronics standard without support of C3 mode (like many other RAM expansions) * second SRAM: upgrade to 1024K (512K SRAM) or optionally also 640K (128K SRAM)* [http://norecess.cpcscene.net/advancedmemoryusage.html C3 RAM banking] supported if both SRAMs are fitted* easy to assemble, all through-hole componentsgallery>
Status: working, currently testing, maybe needs another PCB revision
=== CPC iRAM/1024s ===
* much smaller than iRAM/1024, more similar in size to iRAM/640
* for CPC 464 and 664
* single 1MB SMD SRAM, upgrade to 1024K* including [http://norecess.cpcscene.net/advancedmemoryusage.html C3 RAM banking] supported* easy to assemble, mostly through-hole components but one SMD SRAM Status: prototype assembled, not tested yet == considered == === PLUS iRAM/1024 === * 1Mb upgrade for Plus series * less DIY friendly, probably needs more complex CPLDs (ATF150x) Status: very early stage, still considering if it's feasible === GX iRAM/512 === * 512K upgrade for GX4000* less DIY friendly, probably needs more complex CPLDs (ATF150x) Status: just an idea == abandoned == === CPC iRAM/576 === * support for CPC 6128 onlycompatibility* 512K expansion* total accessible RAM of alternatively without C3 support 576K in a 6128 or 1088K (following the DK'Tronics standardone or two SRAMs fitted)
* easy to assemble, all through-hole components
StatusRepository: https: Abandoned in favor of the iRAM/640 which uses the exact same components but offers more total memory. === CPC iRAM/512 === * for CPC 464/664* 512K expansion* total accessible RAM of 512K in a CPC, following the DK'Tronics standard and support of C3 modegithub. * or 576K without C3 support (512K_C3 com/etomuc/ 576K selection per manual switch)* easy to assemble, all throughCPC464-hole componentsiRAM1024
Status: Abandoned as CPC iRAM/1024 will fit into all 464s/664s and is more flexible
[[Category:Hardware]] [[Category:Memory expansions]] [[Category:DIY| ]]