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 == === CPC iRAM/640 ===
* for CPC 6128 only
* total accessible RAM of 640K in a 6128 (64K Base RAM + 512K RAM expansion + 64K secondary RAM bank of the 6128)
* easy to assemble, all through-hole components
* 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.
Status: Released - see https://github.com/etomuc/CPC6128_iRAM-640
== currently in development == === CPC iRAM/576 1088 ===
* for CPC 6128 only
* 512K 1024K expansion* total accessible RAM of 576K 1088K in a 6128 (64K Base RAM + 1024K RAM expansion)* easy to assemble, but SRAMs are in SMD packaging (SOP32) due to size constraints in the CPC 6128* 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. Status: Finished, will be released in late 2025 === CPC iRAM/1024 === * for CPC 464 and 664* offers two sockets for SRAMs* upgrade to 576K (1 SRAM) or 640K/1024K (2 SRAMS)* first SRAM: Upgrade to 576K, following the DK'Tronics standardwithout 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 components
Status: abandoned as the same components are required as for iRAM/640 with only minimal changes to the working, currently testing, maybe needs another PCB and GAL logic.revision
== currently in development = 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* [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/1088 576 ===
* for CPC 6128 only
* 1024K 512K expansion* total accessible RAM of 1088K 576K in a 6128 (64K Base RAM + 1024K RAM expansionfollowing the DK'Tronics standard)* easy to assemble, but some SMD all through-hole components due to size constraints in the CPC 6128
Status: Prototype successfully tested. Release unclear due to lack Abandoned in favor of demandthe iRAM/640 which uses the exact same components but offers more total memory.
=== CPC iRAM/512 ===
* easy to assemble, all through-hole components
Status: problems with C3 mode when C3 Abandoned as CPC iRAM/1024 will fit into all 464s/664s and is accessed from ROM, currently pausedmore flexible
[[Category:Hardware]] [[Category:Memory expansions]]