Launch options

Many PC games accept launch options: words added after the program's name that change how it starts, such as -windowed or -nointro. In PC5 you give a game its launch options in a text file called launch.txt, placed beside the game's .exe. PC5 reads it each time the game starts.

Adding launch options

1. Find the folder that holds the game's .exe on the console:

   /data/prospero-win/prefixes/<game>/drive_c/Games/<folder>/
   

   • <game> is the game's id: its folder name in lower case, with spaces and other signs turned into dashes (for example neon-drift for Neon Drift). A second game with the same name gets -2 at the end, and so on. The easiest way to find it is to look in /data/prospero-win/prefixes/ for the folder named like the game.
   • <folder> is the game's folder as it was on the USB drive (for example Neon Drift).
   • If the .exe is in a subfolder of the game's folder (for example bin/), go into that subfolder too: launch.txt goes beside the .exe.

   The game's menu (△) shows which program PC5 starts, under Manage › Change program.

2. Make a text file called launch.txt there.

3. Write the options on one line, for example:

   -windowed -nointro
   

4. Start the game. PC5 starts it with these options.

You can also put launch.txt beside the .exe on the USB drive before installing. It is copied with the game.

How PC5 reads launch.txt

• PC5 uses the first line that isn't empty and doesn't start with # or ;. Those lines are comments, so you can keep notes or other options in the file.
• It reads the file each time the game starts, so a change takes effect at the next start.
• Up to 500 characters of the line are used.

For example, this file starts the game with -nointro, and keeps another option for later:

# Launch options for this game
; -windowed
-nointro

A game that starts from a .bat file gets the options in the batch file first, then the ones in launch.txt (placed beside the .bat file). See Games that start from a .bat file.

Changing or removing options

• To change them, edit the line and start the game again.
• To start the game without options, delete launch.txt, or put # in front of the line.

Which options a game accepts

That is up to the game. Look for the game's PC launch options: the ones you would put in Steam's "Launch options", or in a shortcut's target on Windows.

Don't edit the game's profile in /data/prospero-win/profiles/ instead: PC5 writes it again each time the game starts. launch.txt is the place for launch options.

A game's environment variables (env.txt)

Some games read environment variables, the way a fix on PCGamingWiki or a game's own documentation may ask you to set one. In PC5 you set them for one game in a text file called env.txt, in the game's pc5 folder:

/data/prospero-win/prefixes/<game>/pc5/env.txt

<game> is the game's id, as above. Write one variable per line, as NAME=value, for example:

# Turns off the game's crash monitor
MY_GAME_NO_MONITOR=1

• PC5 reads the file each time the game starts, so a change takes effect at the next start.
• Lines starting with # are comments. Up to 32 variables are used.
• A name has letters, digits and _ only. Names PC5, prospero-win and Wine set themselves are left out: those starting with WINE, PW_, LD_, PS5 or PC5, and PATH, HOME and TMPDIR. Two kinds are let through:
  • WINE_PS5_SYNC_SPIN_US: how many microseconds a game's thread keeps checking for its next job before it sleeps (100 unless set). WINE_PS5_SYNC_SPIN_US=0 turns it off, for a game that runs worse with it; a higher value, up to 1000, may help a game that wakes its threads very often.
  • WINE_PS5_CURSOR_IDLE_MS: how many milliseconds the mouse pointer stays on screen after you last moved it or clicked (5000 unless set). WINE_PS5_CURSOR_IDLE_MS=0 never hides it, for a game you play with the pointer where it has to stay in sight.
  • PW_NATIVE_PROFILE=1, PW_VK_RADV_PROFILE=1, PW_NATIVE_SLOW_SYSCALL_US and PW_VK_RADV_EVENT_US: a per-frame profile that records where each frame's time goes, for finding what slows a game down. It makes the log much bigger (PC5 keeps 16 MB parts of it while it's on) and the game a little slower, so delete the lines when you're done.
• The game's log says which were set: PC5 env.txt set=1 MY_GAME_NO_MONITOR.

To stop using them, delete env.txt, or put # in front of a line.

See also Files and folders for where everything else is.