MMCE (Multi-Purpose Memory Card Emulator) beta
New page, compiled from community documentation and this SDK's own package source. Unlike the PS2 architecture section, most of it isn't checkable against this SDK's own source - treat it as a starting point, not gospel, and flag anything that looks wrong.
MMCE is a community protocol (and family of hardware) that makes a memory card slot capable of far more than 8MB of saves. It's not part of this SDK's own hardware model - it's an ecosystem convention this SDK has a real, working driver for.
What it actually is
A "smart" memory card - real hardware sitting in the memory card slot - that emulates the standard memory card protocol over SIO2 while actually backing storage with a microSD card. Two real implementations:
- SD2PSX - open source and open hardware (developer
@xyzz;sd2psxtdis a popular extended firmware fork). - MemCard Pro 2 - a commercial product (8BitMods).
Because it's SD-card-backed, it holds effectively unlimited save data instead of one memory card's worth - and because the SIO2 protocol itself is emulated (not just the storage), a standard PS2 doesn't need any special support to use one as a plain memory card.
A newer extension to the protocol goes further: the card can also serve game data, not just saves, letting a loader like Open PS2 Loader boot a full game directly off the card, switching between a per-game "virtual" memory card and the actual game data as needed.
This SDK's driver family
sdk-world's mmceman package is really three separate IOP modules built from the same real upstream source (ps2-mmce/mmceman v2.1.1, MIT), each doing a different job:
| Package | IRX | Role |
|---|---|---|
mmceman | mmceman.irx | The full driver - registers a real IOP filesystem device (iomanX_AddDrv-based). |
mmcedrv | mmcedrv.irx | A minimal variant - just sector-level read/write/seek exports, no device registration. Meant for in-game use, once a loader has already switched the memory-card port into MMCE mode. |
mmceigr | mmceigr.irx | The smallest of the three - a single-shot module that issues MMCE's in-game reset (IGR), switching back to the boot memory card. No imported kernel functions at all - just inline SIO2 register access. |
Which one(s) you need depends on what your program is doing: a loader that needs to browse/manage the card wants the full mmceman; a game that just needs to read/write its own save data after a loader has already done the switching wants the lighter mmcedrv; something that needs to hand control back to the original memory card (returning to a menu, for instance) wants mmceigr.
See also
- Controllers - the SIO2 bus MMCE emulates on top of
- Storage - the standard memory-card driver stack (
mc/mcman/mcserv) MMCE is a drop-in alternative to - PSU - the file format community memory-card content gets packaged in, a separate concern from the hardware/ protocol on this page