# Options

Choose **Options** on the main menu to open kat5200's configuration. It is a
tabbed window; the tabs across the top are:

- **System** ([Machine](machine.md)) — system type, RAM, TV standard, OS/BIOS,
  BASIC, SIO patch, attached media, controller ports, and POT tuning.
- **Graphics** ([Video](video.md)) — renderer backend, window/scaling, the NTSC
  artifacting filter, palette, and shader bundles.
- **Sound** ([Sound](sound.md)) — enable/disable audio, frequency, buffer size,
  and volume.
- **Input** ([Input](input.md)) — per-player controllers, the keyboard, UI
  controls, and analog tuning.
- **Misc** ([Misc](misc.md)) — the Setup window, Configuration (start-up
  behavior, throttle, factory reset), Palette import, Create Media, Log, the
  debugger, and the Manual.

!!! note "Page names vs. tab names"
    Some pages keep their historical filenames (Machine, Video) while the GUI tab
    is labelled **System** and **Graphics** respectively. The page describes the
    matching tab.

## Global vs. per-ROM settings

kat5200 no longer uses named, user-managed profiles in the GUI. Instead, most
configuration tabs (System, Graphics, Sound, Input) offer two save buttons:

- **Save** — write the change to your **global** defaults (the `All` profile).
- **Save for ROM only [*]** — write the change only for the **currently selected
  ROM**, leaving your global defaults untouched.

Always press a **Save** button after changing settings; unsaved changes are only
temporary. When you launch a ROM that has its own saved settings, those override
the global values for that session. ROM-specific settings are marked with an
asterisk (`*`). To revert a ROM to the defaults, use **Clear Custom Settings** in
the [Launcher](../launcher/rom-settings.md).

## How settings are saved

Changes are written to `kat5200.conf` (TOML) in your config directory. Internally,
kat5200 tracks exactly which fields changed and saves only those, so editing one option
will not disturb unrelated settings. Per-ROM overrides are stored in that ROM's
profile file. Nothing is persisted until you press a **Save** button.
