Mu

Mu emulates Palm OS. It reads 5 files, 1 of them required: without a required file it does not start games.

About this profile

Detail	Value
Type	libretro
Classification	Pure libretro
Source	https://github.com/SquirrelJME/Mu
Upstream	https://github.com/meepingsnesroms/Mu
Version	v1.3.3, stated in libretroBuildSystem/libretro.c
Revision	SquirrelJME/Mu@afaeb157b8ba
Profiled	2026-03-24
Profile	YAML, JSON
Cores	mu
Systems	Palm OS

Install this emulator's files

The installer finds your setup and its BIOS folder, then downloads only the files this emulator reads there and checks each one.

Windows

Open the Start menu. Type PowerShell and open it. Paste the line. Press Enter.

PowerShell

&([scriptblock]::Create((irm https://abdess.github.io/retrobios/i.ps1))) --emulator mu

macOS

Open Terminal, in Applications, then Utilities. Paste the line. Press Return.

Terminal

curl -fsSL https://abdess.github.io/retrobios/i | sh -s -- --emulator mu

Linux

Open a terminal. Paste the line. Press Enter.

Terminal

curl -fsSL https://abdess.github.io/retrobios/i | sh -s -- --emulator mu

Steam Deck

Switch to Desktop Mode. Open Konsole. Paste with Ctrl+Shift+V. Press Enter.

Terminal

curl -fsSL https://abdess.github.io/retrobios/i | sh -s -- --emulator mu

Android (Termux)

Install Termux, a terminal app. Run pkg install python and termux-setup-storage once. Then paste the line. Press Enter.

Terminal

curl -fsSL https://abdess.github.io/retrobios/i | sh -s -- --emulator mu

On the device

Open a terminal on the device. Or connect from a computer with SSH, a terminal over the network. Paste the line. Press Enter.

Terminal

curl -fsSL https://abdess.github.io/retrobios/i | sh -s -- --emulator mu

Platform details

• palm_m5xx:

  • rom_size: 4194304
  • bootloader_size: 512
  • cpu: MC68VZ328
  • source_ref: include/m5XXBus.h:23, include/m5XXBus.h:28, src/emulator.c:191-212

• tungsten_t3:

  • rom_size: 16777216
  • cpu: PXA260 (ARM)
  • source_ref: include/tungstenT3Bus.h:17, src/emulator.c:145-162

Technical notes

Mu emulates Palm m500, Palm m515, and (with EMU_SUPPORT_PALM_OS5) Tungsten T3. A Palm OS ROM dump is required. The core selects the ROM filename based on the "OS Version" core option: Palm m500 / Palm OS 4.0 -> palmos40-en-m500.rom Palm m515 / Palm OS 4.1 -> palmos41-en-m515.rom (default) Tungsten T3 / Palm OS 5.2 -> palmos52-en-t3.rom Tungsten T3 / Palm OS 6.0 -> palmos60-en-t3.rom

ROM path: RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY + "/" + osVersion + ".rom". No hash or size validation: the code reads whatever file is present. The bootloader is optional and ignored for Tungsten T3. Supports no-game mode (boots Palm OS desktop from ROM without content).

Files

5 files: 1 required, 4 optional.

In this collection: 5 in repo and 0 missing.

Required

palmos41-en-m515.rom required in repo

Palm m515 ROM, Palm OS 4.1 English

• System: Palm OS
• Default ROM. Selected when core option is 'Palm m515/Palm OS 4.1'.

• Collection copy: bios/Palm/Palm/palmos41-en-m515.rom
• Platforms: palmos41-en-m515.rom: Lakka, RetroArch, RetroPie. palm/palmos41-en-m515.rom: Recalbox

Source

• Asked for by: libretro glue
• Source: libretroBuildSystem/libretro.c:173-176 (libretro glue), libretroBuildSystem/libretro.c:744-763 (libretro glue)

Optional

palmos40-en-m500.rom optional in repo

Palm m500 ROM, Palm OS 4.0 English

• System: Palm OS
• Selected when core option is 'Palm m500/Palm OS 4.0'.

• Collection copy: bios/Palm/Palm/palmos40-en-m500.rom
• Platforms: palmos40-en-m500.rom: Lakka, RetroArch, RetroPie

Source

• Asked for by: libretro glue
• Source: libretroBuildSystem/libretro.c:169-172 (libretro glue)

palmos52-en-t3.rom optional in repo

Tungsten T3 ROM, Palm OS 5.2.1 English

• System: Palm OS
• Selected when core option is 'Tungsten T3/Palm OS 5.2.1'. Requires EMU_SUPPORT_PALM_OS5 compile flag.

• Collection copy: bios/Palm/Palm/palmos52-en-t3.rom
• Platforms: palmos52-en-t3.rom: Lakka, RetroArch, RetroPie

Source

• Asked for by: libretro glue
• Source: libretroBuildSystem/libretro.c:178-181 (libretro glue)

palmos60-en-t3.rom optional in repo

Tungsten T3 ROM, Palm OS 6.0 English

• System: Palm OS
• Selected when core option is 'Tungsten T3/Palm OS 6.0'. Requires EMU_SUPPORT_PALM_OS5 compile flag.

• Collection copy: bios/Palm/Palm/palmos60-en-t3.rom
• Platforms: palmos60-en-t3.rom: Lakka, RetroArch, RetroPie

Source

• Asked for by: libretro glue
• Source: libretroBuildSystem/libretro.c:182-185 (libretro glue)

bootloader-dbvz.rom optional in repo

MC68VZ328 UART bootloader

• System: Palm OS
• Optional for m500/m515. Ignored for Tungsten T3.

• Collection copy: bios/Palm/Palm/bootloader-dbvz.rom
• Platforms: bootloader-dbvz.rom: Lakka, RetroArch, RetroPie. palm/bootloader-dbvz.rom: Recalbox

Source

• Asked for by: libretro glue and emulator code, libretro port
• Source: libretroBuildSystem/libretro.c:766-782 (libretro glue), src/dbvz.c:1408-1423 (emulator code, libretro port)

Next steps

• Get your files, for the setup you play on
• Every system, and the files each one needs
• When a game does not start

Data as of 4 November 2026.