Official page: frank.rh1.tech — hub for all FRANK boards and firmware.
Prince of Persia for Raspberry Pi Pico 2 (RP2350) with HDMI output, SD card, and PS/2 keyboard.
Based on SDLPoP — an open-source port of Prince of Persia.
This firmware is designed for the following RP2350-based boards with integrated HDMI, SD card, PS/2, and PSRAM:
- FRANK — A versatile development board based on RP Pico 2, HDMI output, and extensive I/O options.
- Murmulator — A compact retro-computing platform based on RP Pico 2, designed for emulators and classic games.
Both boards provide all necessary peripherals out of the box—no additional wiring required.
- Native 320×200 HDMI video output via PIO
- 8MB QSPI PSRAM support for game data
- SD card support for game resources and saved games
- PS/2 and USB keyboard input
- I2S audio output
- Raspberry Pi Pico 2 (RP2350) or compatible board
- 8MB QSPI PSRAM (mandatory!)
- HDMI connector (directly connected via resistors, no HDMI encoder needed)
- SD card module (SPI mode)
- PS/2 or USB keyboard
- I2S DAC module (e.g., TDA1387) for audio output
FRANK Prince requires 8MB PSRAM to run. You can obtain PSRAM-equipped hardware in several ways:
- Solder a PSRAM chip on top of the Flash chip on a Pico 2 clone (SOP-8 flash chips are only available on clones, not the original Pico 2)
- Build a Nyx 2 — a DIY RP2350 board with integrated PSRAM
- Purchase a Pimoroni Pico Plus 2 — a ready-made Pico 2 with 8MB PSRAM
Two GPIO layouts are supported: M1 and M2. The PSRAM pin is auto-detected based on chip package:
- RP2350B: GPIO47 (both M1 and M2)
- RP2350A: GPIO19 (M1) or GPIO8 (M2)
| Signal | M1 GPIO | M2 GPIO |
|---|---|---|
| CLK- | 6 | 12 |
| CLK+ | 7 | 13 |
| D0- | 8 | 14 |
| D0+ | 9 | 15 |
| D1- | 10 | 16 |
| D1+ | 11 | 17 |
| D2- | 12 | 18 |
| D2+ | 13 | 19 |
| Signal | M1 GPIO | M2 GPIO |
|---|---|---|
| CLK | 2 | 6 |
| CMD | 3 | 7 |
| DAT0 | 4 | 4 |
| DAT3/CS | 5 | 5 |
| Signal | M1 GPIO | M2 GPIO |
|---|---|---|
| CLK | 0 | 2 |
| DATA | 1 | 3 |
| Signal | M1 GPIO | M2 GPIO |
|---|---|---|
| DATA | 26 | 9 |
| BCLK | 27 | 10 |
| LRCLK | 28 | 11 |
- Install the Raspberry Pi Pico SDK (version 2.0+)
- Set environment variable:
export PICO_SDK_PATH=/path/to/pico-sdk - Install ARM GCC toolchain
# Clone the repository with submodules
git clone --recursive https://github.com/rh1tech/frank-prince.git
cd frank-prince
# Or if already cloned, initialize submodules
git submodule update --init --recursive
# Build using the build script (recommended)
./build.sh # Build M1 @ 378 MHz (default)
./build.sh --board M2 # Build for M2 layout
./build.sh --board M1 --cpu 504 # Build M1 @ 504 MHz
./build.sh clean --board M2 # Clean rebuild for M2
# Or build manually with CMake
mkdir build && cd build
cmake -DBOARD_VARIANT=M1 -DCPU_SPEED=378 -DPSRAM_SPEED=133 ..
make -j$(nproc)| Option | Description |
|---|---|
--board M1 or -b M1 |
Use M1 GPIO layout (default) |
--board M2 or -b M2 |
Use M2 GPIO layout |
--cpu 252|378|504 |
CPU speed in MHz (default: 378) |
--psram 100|133|166 |
PSRAM speed in MHz (auto-selected) |
clean |
Delete build directory and rebuild |
Speed presets:
- 252 MHz CPU → 100 MHz PSRAM (no overclock)
- 378 MHz CPU → 133 MHz PSRAM (medium overclock)
- 504 MHz CPU → 166 MHz PSRAM (max overclock)
To build all 6 variants (M1/M2 × 3 speeds) with version numbering:
./release.sh # Interactive version prompt
./release.sh 1.04 # Use version 1.04 from command lineThis creates versioned UF2 files in the release/ directory:
frank-prince_m1_252_100_X_XX.uf2frank-prince_m1_378_133_X_XX.uf2frank-prince_m1_504_166_X_XX.uf2frank-prince_m2_252_100_X_XX.uf2frank-prince_m2_378_133_X_XX.uf2frank-prince_m2_504_166_X_XX.uf2
# With device in BOOTSEL mode:
picotool load build-make/frank-prince.uf2
# Or with device running:
picotool load -f build-make/frank-prince.uf2
# Or use the flash script:
./flash.sh- Format an SD card as FAT32
- Download prince.zip and extract it
- Copy the
princefolder to the root of your SD card
When upgrading from version 1.00, copy the prince/midi_cache directory from the new archive to your SD card's prince folder.
Note: The MIDI cache contains pre-rendered audio for all MIDI music tracks (~62 MB). If the cache files are missing or outdated, they will be regenerated automatically during gameplay. Regeneration takes additional time during game loading.
- Arrow keys: Move/Run/Climb
- Shift: Walk carefully / Pick up items
- Up Arrow: Jump (while running) / Climb up
- Down Arrow: Crouch / Climb down
- Space: Show remaining time
- Escape: Pause / Menu
- Ctrl+A: Restart level
- Ctrl+R: Quickload
- Ctrl+Q: Quit
- Alt+F1..F12: Start at level 1-12
- Alt+Shift+F1: Start at level 13
- Alt+Shift+F2: Start at level 14
- Alt+Esc: Toggle cheat mode on/off
When cheat mode is enabled:
- Shift+L: Skip to next level
- K: Kill current guard
- R: Resurrect kid
- Shift+T: Add max hit point (big potion)
- Shift+S: Restore hit point (small potion)
- Shift+W: Feather fall (slow falling)
- Shift+I: Flip screen upside down
- Shift+B: Toggle blind mode
- +/- (numpad): Add/subtract time
- H/J/U/N: View room left/right/up/down
- Ctrl+B: Return view to kid's room
- C: Show current room info
- Shift+C: Show adjacent room info
GNU General Public License v3. See LICENSE for details.
This project is based on:
- SDLPoP by David Nagy — Open-source port of Prince of Persia
Mikhail Matveev <xtreme@rh1.tech>
- Jordan Mechner for the original Prince of Persia
- David Nagy for the SDLPoP open-source port
- The Raspberry Pi foundation for the RP2350 and Pico SDK