mx4sio

MX4SIO SD Card

MX4SIO is an SD-card adapter that plugs into memory-card slot 2 and talks to the console over the same SIO2 bus. Launchstation treats the card as a normal FAT32/exFAT BDM device for browsing, applications, ISOs, VCDs and Ember games.

It shares a bus with memory card slot 2 and with MMCE

While the MX4SIO driver is active, slot 2 belongs to the adapter. Opening mc1: makes Launchstation reset the IOP back to the memory-card stack, and loading MMCE does the same. MMCE and MX4SIO cannot be active together, and transfers between MX4SIO and mc1: or between MX4SIO and MMCE are refused. Slot 1 (mc0:) is unaffected.

Opening MX4SIO

The device card is MX4SIO SD Card (mx4sio:). It starts Not connected (not checked). Selecting it loads the MX4SIO block driver on top of the BDM core, then retries opening mx4sio:/ for up to two seconds so a slow SD card can finish mounting. A readable card reads Ready (slot 2); otherwise No MX4SIO storage found. If an MMCE stack is resident, the IOP is reset first (audio and controller are rebuilt); if that reset is refused the driver is not loaded and the card reports as absent.

Settings > Storage & devices > Start devices automatically > Auto-start MX4SIO (off by default) loads it at start. Enabling it turns the MMCE auto-start off, and you cannot enable it while booted from MMCE.

Using the card

Use	Notes
File Browser	List, copy, rename, delete; FAT32 and exFAT.
Applications	Only the folders listed under Settings > Home & applications > Application library > Application folders are scanned; add a folder such as mx4sio:/APPS if you want the library to include the card.
Neutrino ISO	Backend mx4sio; ISO and (optionally) Neutrino can be on the card.
POPStarter VCD	mx4sio:/POPS/*.VCD with POPSTARTER.ELF next to it.
Ember	Umbrella folder anywhere on the card; the existing mount is kept for the hand-off.
IGR	If Launchstation is started from MX4SIO, the IGR trampoline is placed on a physical memory card (slot 1 is tried first); see IGR.

Neutrino’s optional MMCE Game ID card switch is skipped entirely while MX4SIO is active, and per-game Neutrino profiles are not written to a memory card while the MX4SIO stack owns the bus.

Limits

• Not at the same time as MMCE or mc1: (see above). Stack changes reset the IOP, so other device checks are repeated afterwards.
• Numbering: an MX4SIO card can also take a massN: name from the shared BDM namespace; use the MX4SIO SD Card device rather than a remembered number.
• Adapter and SD card compatibility (speed class, size, firmware) is not catalogued; report the adapter model.
• Loading shows a frame before the blocking driver call and refreshes again when it returns, but cannot animate during a call that stalls.

Troubleshooting

1. “No MX4SIO storage found”. Check the adapter is in slot 2, the card is FAT32/exFAT, and no MMCE adapter is in the way of the IOP reset. Try Detect now.
2. Card appears slowly or after a retry. Mount settling is tolerated for two seconds; slower cards may need a second Detect now.
3. Memory card slot 2 is missing. It returns when you open mc1:; Launchstation resets the IOP for you.
4. Frame drops while loading. Module entry is a synchronous call; report console model, adapter and build hash.