nuPSX is an experimental PlayStation 1 emulator and debugger written in Zig, built as a learning exercise to explore Zig's capabilities and PSX hardware architecture. Still in early development with no intention of becoming usable by the general public. If you are looking for the emulator to play games, check out DuckStation.

Can boot and play a few commercial games (notably Crash Bandicoot and MGS) and homebrew demos. Lots of things are still missing or incomplete. Tested 2D games are mostly fine, 3D games have minor graphical glitches. Sound system is not complete but functional enough to play music and most of sound effects in tested games.

🟥 Nothing - Doesn't boot or crashes the emulator
🟧 Intro - Boots into the title screen or main menu but doesn't get past it
🟨 InGame - Boots into the game but has major issues
🟩 Playable - Boots into the game with minor or no issues

Below are links to the latest prebuilt binaries. I don't have enough computers so not all of them are tested.

• nupsx-aarch64-linux-gnu.zip
• nupsx-x86_64-linux-gnu.zip
• nupsx-aarch64-macos.zip
• nupsx-x86_64-macos.zip
• nupsx-x86_64-windows.zip

git clone https://github.com/maxpoletaev/nupsx.git
cd nupsx
zig build --release=safe
./zig-out/bin/nupsx --bios SCPH1001.bin

nuPSX - A PlayStation emulator

Usage: nupsx --bios <path> [options]

Options:
  --bios <path>        Path to BIOS file (required)
  --exe <path>         Path to executable file to run
  --cdrom <path>       Path to CD-ROM image file (.cue)
  --debug              Enable debug user interface
  --disasm             Enable disassembly output
  --breakpoint <addr>  Set a breakpoint at the specified address (hexadecimal)
  -h, --help           Show this help message

    [ Q ]                    [ O ]
  _/[ E ]\_       ┆┆       _/[ U ]\_
 /         \--------------/         \
|    [W]    |            |    [I]    |
| [A]   [D] |            | [J]   [L] |
|    [S]    | SHFT ENTR⟩ |    [K]    |
|\_________/--------------\_________/|
|       /                    \       |
|      /                      \      |
 \____/                        \____/

  ↑ = W     △ = I     [START]  = Enter
  ← = A     ◻ = J     [SELECT] = R-Shift
  ↓ = S     × = K     [L1] = E  [R1] = U
  → = D     ◯ = L     [L2] = Q  [R2] = O

nuPSX relies on zig-gamedev libraries for graphics, audio and ImGui bindings.

Special thanks to guys in EmuDev Discord for sharing tons of undocumented knowledge and getting me unstuck countless times.

Readings:

• PSX-SPX Playstation Specifications by Martin "nocash" Korth
• PlayStation Emulation blog post series by James Groth
• PlayStation Emulation Guide (PDF) by Lionel "simias" Flandrin
• The PS1 GPU texture pipeline and how to emulate it reddit post by an unknown author

Tests and Demos:

• https://psx.amidog.se/doku.php
• https://github.com/PeterLemon/PSX
• https://github.com/JaCzekanski/ps1-tests

Referenced Projects:

• https://github.com/allkern/psxe
• https://github.com/stenzek/duckstation
• https://github.com/JaCzekanski/Avocado