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RetroBIOS

GSplus (legacy)

GSplus (legacy) emulates Apple IIGS. It reads 9 files, 1 of them required: without a required file it does not start games.

About this profile
Detail Value
Type standalone
Classification Community fork
Source https://github.com/digarok/gsplus-legacy-archive
Version 0.14
Revision digarok/gsplus-legacy-archive@480572054518
Built by recalbox, batocera, retrobat, under its core name. The libretro buildbot does not publish this build.
Profiled 2026-10-20
Profile YAML, JSON
Cores gsplus
Systems Apple IIGS
Install this emulator's files

With Batocera, Recalbox, RetroBat or KNULLI: the installer finds Batocera, Recalbox, RetroBat or KNULLI and its BIOS folder, then downloads only the files GSplus (legacy) reads there and checks each one.

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

PowerShell
&([scriptblock]::Create((irm https://raw.githubusercontent.com/Abdess/retrobios/main/install.ps1))) --emulator gsplus-legacy
Technical notes

The first GSplus, a GSport descendant of KEGS 0.91 kept by digarok as gsplus-legacy-archive. It shares no history with digarok/gsplus, a new import of KEGS 1.38 profiled as gsplus. It reports itself as 0.14 (src/sim65816.c:184).

Recalbox builds this commit (recalbox package/gsplus/gsplus.mk:8-9 at tag 10.1.1). Batocera builds applemu/gsplus dc1835d6, a fork that descends from this commit and leaves the ROM and font loading untouched (batocera package/batocera/emulators/gsplus/gsplus.mk:7-8 at tag batocera-43.1). RetroBat runs the gsplus-win-sdl release build (emulatorlauncher emulatorLauncher/Generators/GsPlus.Generator.cs:26-30).

Every file is looked up by setup_gsplus_file, which tries each name in order inside each directory of g_gsplus_default_paths before moving to the next directory (src/sim65816.c:56-70, 1018-1046). The directories are the name as given, ./, $HOME/, $PWD/, $HOME/Library/GSplus/, /usr/local/lib/, /usr/lib/gsplus/, /usr/local/gsplus/, /usr/local/lib/gsplus/, /usr/share/gsplus/, /var/lib/ and the executable directory, which is ./ outside macOS (src/sim65816.c:54, 987-988).

The config file is the first of config.txt, config.gsp and .config.gsp found on that path, and GSplus creates $HOME/.config.gsp when none exists (src/config.c:177-179, 650, src/sim65816.c:1060-1090). It carries g_cfg_rom_path, the disk assignments and the battery RAM.

Slot 6 gets a Disk II PROM rebuilt from the IIGS ROM through g_rom_c600_rom01_diffs[] (src/config.c:542, 918-929). Slots 2 to 5 and 7 have empty name lists, so only slots 1 and 6 read a card ROM from disk (src/config.c:527-533, 932-959).

Files

Section titled “Files”

9 files: 1 required, 8 optional. 1 has an HLE fallback.

File Required
ROM yes
c600.rom no
parallel.rom no
lib/letgothl.ttf no
sansserif.ttf no
courier.ttf no
prestige.ttf no
script.ttf no
ocra.ttf no

In this collection: 8 in repo and 1 missing.

Required

Section titled “Required”

ROM required in repo

Apple IIGS system ROM

  • Size: 128.0 KB / 256.0 KB
  • Aliases: ROM1, ROM3, ROM01, ROM03, ROM.01, ROM.03
  • g_cfg_rom_path, ROM unless the config file sets it, is tried first, then ROM, ROM1, ROM3, ROM01, ROM03, ROM.01 and ROM.03. A 131072-byte file runs as a ROM 01 machine and a 262144-byte file as a ROM 03 machine. Any other size is refused. Without a ROM, GSplus shows a missing ROM alert and opens its config panel instead of starting (src/config.c:868-872, src/sim65816.c:1053-1063).

Optional

Section titled “Optional”
8 files

c600.rom optional in repo HLE fallback

Disk II controller PROM for slot 6

  • Size: min 256 B
  • Aliases: controller.rom, disk.rom, DISK.ROM, diskII.prom
  • Replaces the built-in PROM. The first 256 bytes are read into slot 6 and a shorter file is rejected.

parallel.rom optional in repo

Parallel printer card ROM for slot 1

  • The first 256 bytes are read into slot 1 and a shorter file is rejected. Without it the slot 1 ROM space stays zeroed. The project keeps the file at src/parallel.rom and ships it beside gsplus.exe in its Windows release.

letgothl.ttf optional in repo

Default printer font (Epson LQ Roman, ImageWriter fixed and proportional)

  • Path: lib/letgothl.ttf

sansserif.ttf optional in repo

Epson LQ Sans Serif printer font

  • Opened from the working directory when the Epson LQ selects this typeface.

courier.ttf optional in repo

Epson LQ Courier printer font

  • Opened from the working directory when the Epson LQ selects this typeface.

prestige.ttf optional missing

Epson LQ Prestige printer font

  • Opened from the working directory when the Epson LQ selects this typeface.

script.ttf optional in repo

Epson LQ Script printer font

  • Opened from the working directory when the Epson LQ selects this typeface.

ocra.ttf optional in repo

Epson LQ OCR-A and OCR-B printer font

  • Opened from the working directory when the Epson LQ selects OCR-A or OCR-B.

Next steps

Section titled “Next steps”
.

Maintained by Abdess on GitHub. Report a problem.

Packs from release v2026.10.10, .

MIT for the tooling and metadata. BIOS and firmware files are third-party system software, preserved for personal backup, archival and interoperability.