PS2 OPL 1.2.0 MX4SIO Not Being read

[Trashboat]

Hello,

I'm trying to play games from my SD card. I have most everything else set up, but OPL 1.2.0 isn't pulliong the games from my SD card up in the browser.

Is there a way to tell if maybe my MX4SIO card is the issue.

• I've tried two different SD cards
• I've used both OPL 1.1.0 and 1.2.0's most recent beta (as of 2/8/2026)
• I can read the SD card on my PC, but the data doesn't seem to show up on ULaunchElf under mc1

I'm trying to figure out what the issue is. I also had to change BDM loading to Manual since Auto wasn't working, but the games on the card aren't showing up in OPL.

I'm also not sure if I should reinstall FMCB. I changed the version of OPL multiple times, but it still says 1.2.0.

 

[Berion]

MX4SIO isn't PS2 Memory Card, so it will not show up under "mc0:/" or "mc1:/". Also using different logic structure than expected. For see MX4SIO contents (SD card contents), you need to use wLE ISR MX4SIO. You can test card by dedicated testing app. Both you can find i.e in R4D:
https://www.psx-place.com/resources/recovery-for-dummies.1520/

Did you turn on MX4SIO in OPL settings? :P

FMCB have nothing to do with OPL and MX4SIO.

 

[Trashboat]

MX4SIO isn't PS2 Memory Card, so it will not show up under "mc0:/" or "mc1:/". Also using different logic structure than expected. For see MX4SIO contents (SD card contents), you need to use wLE ISR MX4SIO. You can test card by dedicated testing app. Both you can find i.e in R4D:
https://www.psx-place.com/resources/recovery-for-dummies.1520/

Did you turn on MX4SIO in OPL settings? :P

FMCB have nothing to do with OPL and MX4SIO.

Sorry for the long delay, but I have an update. I found a reddit thread where someone was having a similar issue, and they used a specific PR for OPL that read their SD card. It also taught me that I wasn't properly replacing the OPL.ELF files using FMCB config.

So I used the version of OPL they did by testing from my USB and it worked. The games are being read from my mx4sio and can be played. However, when I moved the ELF from my USB to the FMCB card, the games were still being read, but they never loaded for some reason. Any clue what's going on here?

 

[Berion]

You cannot "improperly replace it". You replacing it or not.

You heard nonsense. But it is possible what "build A" can have working what is broke in "build B". Try different?

 

[Trashboat]

Ok I solved it. Pulled another build I had lying around and actually replaced the old opl with that one, now it works from the FMCB card.

Before I would just paste the ELF file without renaming it, so in some cases when I tried to access OPL from the main menu, it would use the latest build I downloaded, just the one named OPNPS2LD that it could find.