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Creating Custom System Configs

GSSquared lets you build and save your own system configurations — which Apple II model, which cards are in which slots, which disk images to mount at launch, and what is attached to serial/parallel ports.

Saved configs are .gs2 files. You can also open community profile packs that use … Settings.txt files. For hand-editing the file format itself, see Writing Config Files Manually.

From the System Select screen

When you start GSSquared, you see Choose your retro experience with the built-in system tiles (including IIgs ROM 01 and ROM 03), recent custom configs, plus:

  • + — create a new custom config from scratch. Opens the config editor with a default Enhanced //e setup you can change.
  • Edit... — open an existing config file (.gs2 or … Settings.txt) and load it into the editor so you can change it and save.

Hover the + or Edit… tile to see a short description at the bottom of the screen.

Launch Config… (menu)

From the System Select screen, use File → Launch Config….

Pick a .gs2, a .gs2pack, or … Settings.txt file. Unlike Edit..., this loads the config and boots it immediately — it does not open the editor. A .gs2pack is a machine plus its disks in one file; see GS2 Packs. Edit... does not open a pack. The file dialog starts in Documents/GSSquared/ (where shipped examples are copied on first run).

Launch Config is only available when the machine is off (at the System Select screen).

Double-click a .gs2 file

On macOS, .gs2 files are associated with GSSquared. Double-click one in Finder (or use Open With → GSSquared). On Windows, double-click starts GSSquared with the path on the command line; a second click while the app is already running starts another instance.

  • If the System Select screen is showing, GSSquared loads that config and launches it.
  • If emulation is already running, a prompt asks whether to stop the current machine and launch the new config. Cancel keeps the current machine. Launch saves any dirty disks, then boots the new profile.

You can also drag a .gs2 (or … Settings.txt) onto the GSSquared window while at System Select — same result as launching it.

File types, Finder icons, and the gssquared: pack URL are specified in File types and URL protocols.

Open With… for Settings.txt files

Community profile packs (arqyv / A2Fusion) ship as folders with disk images and one or more files named like Something Settings.txt.

These are not double-click associated the way .gs2 is (because we don't want to overload .txt files on your system). To open one:

  1. Right-click the … Settings.txt file.
  2. Choose Open With → GSSquared.

GSSquared loads the profile and boots it, the same as Launch Config. You can also use Launch Config or Edit... and pick the Settings file from the file dialog.

Using the config editor

The editor title is Edit System Configuration. You can set:

  • Name and description — shown on the badge / for your own reference.
  • Platform — Apple II, II+, //e, Enhanced //e, IIgs ROM 01, IIgs ROM 03, etc.
  • Slots — click a slot to pick which card goes there (or None). Card choices include Disk II, BazFast, Mockingboard, Uthernet II, Super Serial, Apple Mouse, Parallel, Videx (II/II+ slot 3), clock cards, VIDHD (65816 //e), Second Sight or Video Overlay Card (IIgs slot 3), language card (slot 0), and Slinky memory expansion.
  • Storage (pre-mount) — click a drive to choose a disk image that will be mounted when you later launch this config. Click again to clear it. Any valid disk image including .pmap (BazFast multi-image) can be "pre-mounted" this way.
  • Serial / Parallel — click a port button and choose None, File, Clipboard, Modem, or a listed host serial port (serial jacks only). See Serial & Parallel Connections.

Speed and Display controls on this screen are for preview only; they are not saved into the config file.

Save writes a .gs2 file (you'll get a save dialog). Save As to a new path mints a new machine id (IIgs BRAM is copied). This is configuration only — not a full CPU/RAM save state (that is planned). Cancel returns to System Select without saving.

After saving, use Launch Config…, double-click the .gs2, or Open With to run it. Recent configs also appear as tiles on System Select.

Machine identity (BRAM)

Each .gs2 file gets a stable id (UUID). On Apple IIgs configs, battery RAM / Control Panel NVRAM is stored in the .gs2 (bram) and written when you close the machine. You normally do not need to edit id by hand; GSSquared assigns one when missing. See Writing Config Files Manually.