Disc swapping¶
Some games in the 32-bit generation were spread over multiple CDs, and at a certain point in the game they ask the user to swap one disc out for another, while the console is still powered on.
To manage discs, libretro has a concept of a disc index (like a multi-disc CD player).
If a Sony PlayStation core or Sega Saturn core is loaded, then a Disc Control option is added to the Quick Menu.
Using 'Eject/Load disc'¶
Load New Disc ejects the current (virtual) disc and opens the File Browser, where you can select a new disc image to be loaded.
When you select Eject Disc, three new options appear:
Insert Disc: Opens the File Browser, to find a disc image and load it into the Disc Index (CD list).Current Disc Index: Displays a list of the current discs in the "CD changer", and lets you select which disc is "in use".Load New Disc: Opens the File Browser, to find another disc image and load it into the Disc Index (CD list).
Using 'Disc Image Append'¶
If you don't or can't use a playlist, you can append a disk image to the list on the fly using Disc Image Append. In this case, you use the File Browser to look for a disk image, and then add it to the internal disk image list. The Disc Index list is updated appropriately, and you can make your selection then return to the game.
Using M3U playlists¶
Multi-CD images are typically handled with an .m3u playlist file. In this case, you can swap disks by cycling through the Disc Index setting.
You can start a game by loading its M3U file, through Load Content or Playlists (This will have to be added manually to your Playlists, as scanning for content will not do so).
Making an M3U playlist file¶
You can make an M3U playlist file using a simple text editor. * Put all of your content's disc files into a single folder. * Create a new text file in the same folder as your content. Name it the same as your content. * Add the full names of each disc into the text file (including the file extension), 1 filename per row. * If your discs are BIN/CUE files, only list the '.cue' files in the document. * If your discs are CHD files, list the '.chd' files in the document. * Save and close the text file. * Rename the file extension from '.txt' to '.m3u'.
Example¶
Contents of folder (ROMS/Metal Gear Solid/):
Metal Gear Solid (USA) (Disc 1).bin
Metal Gear Solid (USA) (Disc 1).cue
Metal Gear Solid (USA) (Disc 2).bin
Metal Gear Solid (USA) (Disc 2).cue
Metal Gear Solid (USA).m3u
Contents of M3U file (Metal Gear Solid (USA).m3u):
Metal Gear Solid (USA) (Disc 1).cue
Metal Gear Solid (USA) (Disc 2).cue
Issues and workarounds¶
Replacing the disk inside RGUI is "physically" speaking the same as ejecting, swapping disks and closing the tray instantaneously. Some games will not work with this approach: Notably Metal Gear Solid needs to detect an actual "eject" taking place.
To work around this, set Disk Index to No Disk, and exit RGUI. The game will pick up that the tray has been ejected/missing disk after half a second or so. Now you can go back to RGUI, pick the correct disk index and return to the game.