This page is the saves hub: virtual PS2 memory cards, save-state slots, and Disc 1–3 swaps. Use a card save for anything you cannot afford to lose after an APK change. Use a state for a boss retry. Keep one shared .ps2 file across a multi-disc RPG so Disc 3 still sees the Disc 1 ending.

Finish the APK install walkthrough so data folders exist, and import a BIOS first — the memory card manager never opens without firmware. Desktop PCSX2 documents the same card-versus-state split on the PCSX2 wiki. Android paths differ; the rule does not.

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## States versus memory cards
Save state overlay next to PS2 memory card files
Save state overlay next to PS2 memory card files
Save stateMemory card
What it storesWhole machine snapshotGame-written save file
Survives emulator updatesOften noUsually yes
Works in cutscenesYesNo
Shares with PCSX2NoYes (.ps2 card)
Multi-discTied to one disc CRCShared across Disc 1–3 if Slot 1 is one file
RiskDesync, crash on loadCard full / format prompt

A state taken on AetherSX2 3668 may not load on 4248. A state from PCSX2 Qt will not load on Android. Card saves from PCSX2 will.

Memory cards

AetherSX2 Memory Cards Slot 1 and Slot 2
AetherSX2 Memory Cards Slot 1 and Slot 2

AetherSX2 emulates two PS2 slots as files, usually Mcd001.ps2 and Mcd002.ps2. Those are the shrine / bed / pause-menu saves. Default setup points both slots at two shared 8 MB images — the same as one physical card in a real console.

Per-game cards (Memory Card settings → folder per game / unique cards) isolate Final Fantasy X from GTA so a full card in one title cannot block another. Use a shared Slot 1 for a multi-disc set. Use per-game cards if you play dozens of RPGs.

8 MB is the classic PS2 size. Larger PCSX2 images work if the format is still .ps2. Do not rename PS1 .mcr files into Slot 1.

Create, format, and import

  1. Open App Settings → Memory Cards.
  2. Slot 1 → Create if the path is empty. Confirm 8 MB unless you know you need a larger image.
  3. Boot any game to the OS browser or in-game save menu. The first access formats the card.
  4. To import, copy a .ps2 file into the emulator's memcards folder and point Slot 1 at that file.

Never edit the .ps2 with a text editor.

From PCSX2: USB the desktop memcards file to the phone. Region must match the BIOS or some titles refuse the save. From a physical card: dump with a reader or homebrew (uLaunchELF). The image must be a PS2 card dump.

On the POCO F3, AetherSX2 v1.5-4248 created Mcd001.ps2 and Mcd002.ps2 in memcards. A desktop PCSX2 card loaded after a format-warning skip. Source for the container: PCSX2 GitHub. Dump hashes: Redump.

When a game cannot see the card

SymptomCauseFix
"Not formatted" every bootSlot path empty or file zero bytesRecreate 8 MB card; do not interrupt first format
Save slot greyed outMulti-disc title looking at the wrong disc's folderKeep one shared card (see multi-disc below)
Import from USA BIOS, PAL gameRegion mismatchMatch BIOS region to the dump
Card fullShared 8 MB exhaustedDelete old saves in-game or switch to per-game cards
After Android 11+ moveScoped storage hid the old pathRe-point Slot 1; restore from backup

If the app crashes on save, check storage permission or a full disk: crash fix.

Save-state slots

AetherSX2 save-state slots in the pause overlay
AetherSX2 save-state slots in the pause overlay
  1. Pause the game (overlay or mapped hotkey).
  2. Save State → pick slot 1–10. Slot 0 is often "quick save."
  3. Load State restores that slot. Do not load during a disc swap mid-write.
  4. Map Save State / Load State on a pad in controller setup so you never hunt the overlay in a boss.

Why a state refuses to load

  • Version mismatch after an APK update or a NetherSX2 patch revision. Keep an in-game save.
  • Wrong game CRC if you replaced the ISO with a different region dump.
  • Renderer change can break GPU-heavy snapshots. Try OpenGL once, then make a new state.
  • Corrupt file from killing the app while the slot was writing. Delete that slot.

On this phone a Final Fantasy X slot was ~42 MB under sstates, one file per CRC per slot. Copying that file to PCSX2 failed. Copying Mcd001.ps2 succeeded.

Safe habits for long RPGs

For Final Fantasy X, Kingdom Hearts, Persona 3/4: shrine/save point is truth. One state as a retry buffer only. Write a card save before a NetherSX2 patch or OS update. Do not spam states every 10 seconds on a dying SD card.

Game pages: Final Fantasy X, Kingdom Hearts.

Multi-disc games

Star Ocean 3 Disc 1, Disc 2, and Disc 3 CHD files
Star Ocean 3 Disc 1, Disc 2, and Disc 3 CHD files

PS2 RPGs such as Xenosaga and Star Ocean 3 span two or three discs. AetherSX2 does not merge them into one file. Each dump stays in the same folder, named so the scanner can group them, and you swap from the pause menu when the game asks for Disc 2.

Name CHD and ISO files so the swap works

Prefer CHD (ISO to CHD):

`` Star Ocean 3 - Till the End of Time (USA) (Disc 1).chd Star Ocean 3 - Till the End of Time (USA) (Disc 2).chd Star Ocean 3 - Till the End of Time (USA) (Disc 3).chd

`

Keep the region identical. Mixing PAL Disc 1 with NTSC Disc 2 boots, then fails the swap checksum. BIN/CUE dumps must keep the .cue next to the .bin. Point AetherSX2 at the cue. CHD tool docs: chdman. Hash dumps against Redump.

Renaming Disc 2 to SO3D2.chd on this phone made it a second row with different artwork. Change Disc still listed it if both files were in the scanned folder.

Swap discs from the pause menu

Change Disc in the AetherSX2 pause overlay
Change Disc in the AetherSX2 pause overlay

When the game shows "Please insert Disc 2":

  1. Open the AetherSX2 overlay (back gesture or mapped hotkey).
  2. Choose Change Disc / Swap Disc.
  3. Pick Disc 2 from the same folder. Do not background the app mid-open on a slow SD card.
  4. Close the overlay.

Do not load a Disc 1 save state after you already swapped — that restores Disc 1 RAM. Use an in-game save on the new disc.

Each disc can have a different CRC, so states are per disc. Card saves should be shared: keep Slot 1 on one Mcd001.ps2. Per-game cards can create one file per CRC and make Disc 3 look empty.

When Disc 2 never appears

SymptomLikely causeFix
Change Disc lists nothingDiscs not in the scanned folderAdd the directory again; wait for rescan
Hang on swapIncomplete CHD / still copying from USBCheck file size vs PC original
"Wrong disc"Different region or translation hackUse a matched set
Audio gone after swapCue sheet missingRestore .cue + tracks
Black screen after swapRenderer glitchChange disc again or see black screen fix

Do not concatenate commercial multi-disc RPGs into one CHD. Mega-packs that already merged discs are unofficial hacks.

Backup before patches and wipes

Copying AetherSX2 memcards to a computer
Copying AetherSX2 memcards to a computer

Copy the memcards folder (and sstates if you care about retry slots) to Drive, a PC, or an SD card before:

  • Applying a NetherSX2 patch
  • Clearing app storage to "fix" a crash
  • Installing an unofficial MMJ APK with a different package name

An 8 MB card is small. There is no reason to skip this. Cloning apps often skip Android/data — copy memcards yourself.

Frequently Asked Questions

Are memory card saves compatible with NetherSX2?

Yes. Same files if you patch the same package. Copy Mcd001.ps2` if you sideload a different package name.

Can I undo a save-state load?

Only if you saved another slot first. Load is destructive to current RAM. Keep slot 9 as a "before experiment" snapshot.

Do widescreen patches invalidate states?

Usually no. If a patch changes guest memory layout, make a new state after enabling 16:9 patches.

Can I concatenate discs into one CHD?

Not for commercial PS2 multi-disc RPGs. One CHD per disc.