stella(6)

NAME
stella - Atari 2600 emulator

SYNOPSIS
stella [options] <ROM file>

DESCRIPTION
stella is a comprehensive emulator of the old Atari 2600 video-game console. It support most Atari 2600 games and many peripherals.

OPTIONS
stella accepts the following options:

-video <opengl|opengles2|opengles|software>
    Use OpenGL, OpenGLES or SDL software rendering mode.

-vsync <1|0>
    Synchronize screen updates to the vertical blank period. This can result in smoother updates, and eliminate tearing.

-fullscreen <1|0>
    Play the game in fullscreen mode (1) or in a window (0).

-center <1|0>
    Centers game window (if possible).

-palette <standard|z26|user>
    Sets the palette to either normal Stella, the one used in the z26 emulator, or a user-defined palette.

-colorloss <1|0>
    Enable/disable the PAL color-loss effect.

-framerate <number>
    Display the given number of frames per second. Normally, Stella will determine framerate based on number of scanlines. Setting this to 0 automatically enables auto-frame calculation (ie, framerate based on scanlines).

-timing <sleep|busy>
    Determines type of wait to perform between processing frames. Sleep will release the CPU as much as possible, and is the preferred method on laptops (and other low-powered devices) and when using GL VSync. Busy will emulate z26 busy-wait behaviour, and use all possible CPU time, but may eliminate graphical 'tearing' in software mode.

-uimessages <1|0>
    Enable or disablEnable or disable display of message in the UI. Note that messages indicating serious errors override this setting, and are always shown.

-sound <1|0>
    Enable or disable sound generation.

-fragsize <number>
    Specify the sound fragment size to use. Under Debian the recommended value is 512.

-freq <number>
    Set sound sample output frequency (0 - 48000). Default is 31400. Do not change unless you experience sound issues.

-volume <number>
    Set the volume (0 - 100).

-tia.zoom <number>
    Use the specified zoom level (integer) while in TIA/emulation mode.

-tia.inter <1|0>
    Use interpolation for the TIA image (results in blending/smoothing of the image).

-tia.aspectn <number>
    -tia.aspectp <number> Specify the amount (as a percentage) to scale the TIA image width in NTSC and PAL mode. Since many video modes do not use square pixels, you can reduce width until the pixels appear square. Allowable values are 80-120; the author finds 85-90 gives the mos authentic look for NTSC, and 105-110 for PAL.

-tia.fsfill <1|0>
    Stretch TIA image completely while in fullscreen mode (vs. an integral stretch which won't necessarily completely fill the screen).

-tv.filter <1-6>
    Blargg TV effects, 0 is disabled, next numbers in sequence represent presets for "Composite", "S-Video", "RGB", "Bad Adjust" and "Custom" modes.

-tv.scanlines <0-100>
    Blargg TV effects scanline intensity, where 0 means completely off.

-tv.scaninter <1|0>
    Blargg TV effects scanline interpolation, resulting in blending/smoothing of the scanlines.

-tv.jitter <1|0>
    Enable or disable TV jitter/roll effect, when there are too many or too few scanlines per frame.

-tv.jitter_recovery <1-20>
    When TV jitter/roll effect is enabled, determines how long to delay recovery time (recovery spread over multiple frames).

-tv.contrast <number>
    Blargg TV effects 'contrast' (only available in custom mode, range -1.0 to 1.0).

-tv.brightness <number>
    Blargg TV effects 'brightness' (only available in custom mode, range -1.0 to 1.0).

-tv.hue <number>
    Blargg TV effects 'hue' (only available in custom mode, range -1.0 to 1.0).

-tv.saturation <number>
    Blargg TV effects 'saturation' (only available in custom mode, range -1.0 to 1.0).

-tv.gamma <number>
    Blargg TV effects 'gamma' (only available in custom mode, range -1.0 to 1.0).

-tv.sharpness <number>
    Blargg TV effects 'sharpness' (only available in custom mode, range -1.0 to 1.0).

-tv.resolution <number>
    Blargg TV effects 'resolution' (only available in custom mode, range -1.0 to 1.0).

-tv.artifacts <number>
    Blargg TV effects 'artifacts' (only available in custom mode, range -1.0 to 1.0).

-tv.fringing <number>
    Blargg TV effects 'fringing' (only available in custom mode, range -1.0 to 1.0).

-tv.bleed <number>
    Blargg TV effects 'bleed' (only available in custom mode, range -1.0 to 1.0).

-cheat <code>
    Use the specified cheatcode (see the Cheat section in the provided documentation for a description of cheatcodes).

-loglevel <0|1|2>
    Indicates level of logging to perform while the application is running. Zero completely disables logging (except for serious errors), while the remaining numbers show increasingly more detail.

-logtoconsole <1|0>
    Indicates that logged output should be printed to the console/commandline as it's being collected. An internal log will still be kept, and the amount of logging is still controlled by loglevel.

-joydeadzone <number>
    Sets the joystick deadzone area for analog joysticks. Accepts a number from 0 - 29, and uses the formula 3200 + number * 1000. So the possible deadzone values range from 3200 to 32200.

-joyallow4 <1|0>
    Allow all 4 directions on a joystick to be pressed simultaneously. Bumper Bash ignores this setting, and always allows all 4 directions.

-usemouse <always|analog|never>
    Use mouse as a controller as specified by ROM properties in specific case. always and never are self-explanatory, analog means only for analog-type devices (paddles, trackball, etc.).

-grabmouse <1|0>
    Keeps the mouse in the game window in emulation mode.

-cursor <0|1|2|3>
    Set mouse cursor state in UI/emulation modes.

-dsense <number>
    Sensitivity for emulation of paddles when using a digital device (joystick digital axis or button, keyboard key, etc.). number may range from 1 to 10, with larger numbers causing faster movement.

-msense <number>
    Sensitivity for emulation of paddles when using a mouse. number may range from 1 to 15, with larger numbers causing faster movement.

-saport <lr|rl>
    Determines how to enumerate the Stelladaptor/2600-daptor devices in the order they are found: 'lr' means first is left port, second is right port, 'rl' means the opposite.

-ctrlcombo <1|0>
    Use control-x key combos. This is normally enabled, since the Quit command is tied to 'Control-q'. However, there are times when a 2-player game is using either the 'f' or 'r' keys for movement, and pressing Control (for Fire) will perform an unwanted action associated with Control-r or Control-f.

-autoslot <1|0>
    Automatically switch to the next available save state slot after saving a ROM state file.

-stats <1|0>
    Overlay console info on the TIA image during emulation.

-fastscbios <1|0>
    Disable Supercharger BIOS progress loading bars.

-snapsavedir <path>
    The directory to save snapshot files to.

-snaploaddir <path>
    The directory to load snapshot files from.

-snapname <int|rom>
    When saving snapshots, use either the internal database name or the actual ROM filename.

-sssingle <1|0>
    Generate single snapshot instead of many, overwriting any previous snapshots.

-ss1x <1|0>
    Ignore any scaling applied to the TIA image, and save snapshot in unscaled (1x) mode.

-ssinterval <number>
    Set the interval in seconds between taking snapshots in continuous snapshot mode (currently, 1 - 10).

-rominfo <rom>
    Display detailed information about the given ROM, and then exit Stella.

-listrominfo
    Prints relevant contents of the Stella ROM database, one ROM per line, and then exit Stella. This can be used for external frontends.

-exitlauncher <1|0>
    Always exit to ROM launcher when exiting a ROM (normally, an exit to launcher only happens when started with the launcher).

-launcherres <WxH>
    Set the size of the ROM launcher.

-launcherfont <small|medium|large>
    Set the size of the font in the ROM launcher.

-launcherexts <allfiles|allroms|list>
    Specifies which files to show in the ROM launcher (allfiles is self-explanatory, allroms is all files with valid ROM extensions (currently: a26, bin, rom, gz, zip), list is a ':' separated list of valid ROM extensions.

-romviewer <0|1|2>
    Hide ROM info viewer in ROM launcher mode (0), or use the given zoom level (1 or 2).

-uipalette <standard|classic>
    Use the specified palette for UI elements.

-listdelay <delay>
    Set the amount of time to wait between treating successive keypresses as a single word in list widgets (value can range from 300-1000).

-mwheel <lines>
    Set the number of lines a mousewheel will scroll in the UI.

-romdir <dir>
    Set the directory where the ROM launcher will start.

-statedir <dir>
    Set the directory in which to save state files.

-cheatfile <file>
    Set the full pathname of the cheatfile database.

-palettefile <file>
    Set the full pathname of the user-defined palette file.

-propsfile <file>
    Set the full pathname of the ROM properties file.

-nvramdir <dir>
    Set the directory in which to save EEPROM files.

-cfgdir <dir>
    Set the directory in which to access Distella config files.

-avoxport <name>
    Set the name of the serial port where an AtariVox is connected.

-maxres <WxH>
    Useful for developers, this sets the maximum size of window that can be created, allowing to simulate testing on 'smaller' systems.

-help
    Print a help message describing these options, and then exit Stella.

The following are useful to developers. Only use them if you know what you're doing! Note that in all cases, the values supplied to the arguments are not case sensitive.

-dis.resolve <1|0>
    Try to differentiate between code vs. data sections in the disassembler. See the Debugger section in the provided documentation for more information.

-dis.gfxformat <2|16>
    Sets the base to use for displaying GFX sections in the disassembler.

-dis.showaddr <1|0>
    Shows/hides opcode addresses in the disassembler.

-dis.relocate <1|0>
    Relocate calls out of address range in the disassembler.

-dbg.res <WxH>
    Set the size of the debugger window.

-dbg.fontstyle <0|1|2|3>
    How to use bold fonts in the debugger window. 0 means all normal font, 1 is bold labels only, 2 is bold non-labels only, 3 is all bold font.

-break <address>
    Set a breakpoint at a specified address.

-debug
    Immediately jump to debugger mode when starting Stella.

-holdjoy0 [UDLRF]
    Start the emulator with the specified left joystick direction and button held down (UF for up and fire).

-holdjoy1 [UDLRF]
    Start the emulator with the specified right joystick direction and button held down (UF for up and fire).

-holdselect
    Start the emulator with the Game Select switch held down.

-holdreset
    Start the emulator with the Game Reset switch held down.

-tiadriven <1|0>
    Set unused TIA pins to be randomly driven high or low on a read/peek.

-cpurandom [SAXYP]
    On reset, randomize the content of the specified CPU registers.

-ramrandom <1|0>
    On reset, either randomize all RAM content, or zero it out instead.

-bs <type>, -type <type>
    Set "Cartridge.Type" property. See the Game Properties section in the provided documentation for valid types.

-channels <Mono|Stereo>
    Set "Cartridge.Sound" property.

-ld <A|B>
    Set "Console.LeftDifficulty" property.

-rd <A|B>
    Set "Console.RightDifficulty" property.

-tv <Color|BlackAndWhite>
    Set "Console.TelevitionType" property.

-sp <Yes|No>
    Set "Console.SwapPorts" property.

-lc <type>
    Set "Controller.Left" property. See the Game Properties section in the provided documentation for valid types.

-rc <type>
    Set "Controller.Right" property. See the Game Properties section in the provided documentation for valid types.

-bc <type>
    Sets both "Controller.Left" and "Controller.Right" properties. See the Game Properties section in the provided documentation for valid types.

-cp <Yes|No>
    Set "Controller.SwapPaddles" property. See the Game Properties section in the provided documentation for valid types.

-ma <Auto|XY>
    Set "Controller.MouseAxis" property. See the Game Properties section in the provided documentation for valid types.

-format <format>
    Set "Display.Format" property. See the Game Properties section in the provided documentation for valid formats.

-ystart <number>
    Set "Display.YStart" property (0 - 64).

-height <number>
    Set "Display.Height" property (210 - 256).

-pp <Yes|No>
    Set "Display.Phosphor" property.

-ppblend <number>
    Set "Display.PPBlend" property, used for phosphor effect (0-100). Default is 77.

-thumb.trapfatal <true|false>
    The default of true allows the Thumb ARM emulation to throw an exception and enter the debugger on fatal errors. When disabled, such fatal errors are simply logged, and emulation continues. Do not use this unless you know exactly what you're doing, as it changes the behaviour as compared to real hardware.

KEYBOARD CONTROLS
The Atari 2600 console controls and controllers are mapped to the computer's keyboard as shown in the following sections. However, most of these events can be remapped to other keys on your keyboard or buttons on your joystick.

  Console controls (can be remapped)

Control + q
    Exit emulator

Escape
    Exit game mode/enter launcher mode

Tab Enter/exit options mode

Backslash (\)
    Enter/exit command mode

Backquote (`)
    Enter/exit debugger

F1  Select Game

F2  Reset Game

F3  Color TV

F4  Black/White TV

F5  Left Player Difficulty A

F6  Left Player Difficulty B

F7  Right Player Difficulty A

F8  Right Player Difficulty B

F9  Save state to current slot

F10 Change current state slot

F11 Load state from current slot

F12 Save PNG snapshot

Pause
    Pause/resume emulation

  Joystick / BoosterGrip Controller (can be remapped)

Left joystick:

Up arrow
    Joystick up

Down arrow
    Joystick down

Left arrow
    Joystick left

Right arrow
    Joystick right

Space
    Fire button

4   Trigger button

5   Booster button

Right joystick:

Y   Joystick up

H   Joystick down

G   Joystick left

J   Joystick right

F   Fire button

6   Trigger button

7   Booster button

  Paddle Controller digital emulation (can be remapped independently of joystick controller)

By default the left paddles are mapped to the left joystick as follows:

Left
    Paddle 0 decrease

Right
    Paddle 0 increase

Fire
    Paddle 0 fire

Up  Paddle 1 decrease

Down
    Paddle 1 increase

Booster
    Paddle 1 fire

The same mappings on the right joystick correspond to the right paddles (paddles 2 and 3 respectively).

  Driving Controller (cannot be remapped, always associated with joystick controllers)
Each driving controller is mapped to the corresponding joystick, using the left, right and fire controls.

  Sega Genesis Controller (cannot be remapped, always associated with joystick and booster-grip controllers)
Each pad is mapped to the correspondig joystick as follows:

Up  Up

Down
    Down

Left
    Left

Right
    Right

Fire
    Button 'B'

Booster
    Button 'C'

  Keypad Controller (can be remapped)

Left keypad (press the key on the left to emulate the key on the right):

1   1

2   2

3   3

Q   4

W   5

E   6

A   7

S   8

D   9

Z   .

X   0

C   #

Right keypad:

8   1

9   2

0 (the digit)
    3

I   4

O (the letter)
    5

P   6

K   7

L   8

;   9

,   .

.   0

/   #

  CompuMate Controller (cannot be remapped)

0-9 0-9

A-Z A-Z

Comma
    Comma

Period
    Period

Control
    Func

Shift
    Shift

; or Return/Enter
    Enter

/ or Space
    Space

Backspace
    Func-Space

FILES

~/.stella/stellarc
    Default options (command line options override these). Lines starting with ';' are considered comments and are ignored. Any other line must be of the form <command> = <value>, where command is the same as that specified on the command line, without the '-' character, and value is the value given to the setting.

~/.stella/atarivox_eeprom.dat
    Default storage for the emulated EEPROM portion of an attached AtariVox device.

~/.stella/savekey_eeprom.dat
    Default storage for the emulated EEPROM portion of an attached SaveKey device.

~/.stella/stella.cht
    Default location of the cheat database file.

SEE ALSO
/usr/share/doc/stella/index.html, /usr/share/doc/stella/debugger.html.

AUTHORS
stella was written by Bradford W. Mott, Stephen Anthony and the Stella Team. This manual page was adapted from the provided documentation by Stephen Kitt <skitt@debian.org>, for the Debian GNU/Linux system (but may be used by others). It was last modified for stella version 3.8.