uae-wii/docs/configuration.txt

Configuring E-UAE
=================

E-UAE may be configured via options supplied in a plain-text configuration
file. This configuration file contains options of the form <key>=<value> and
each new option must begin a new line. Blanks lines are ignored, and lines
beginning with a '#' character are treated as comments and thus also
ignored.

When E-UAE is started it tries to load a default configuration file. Where
it looks for this file is platform-dependent, but typically it will look for
a file called '.uaerc' in the current directory and (on multi-user
platforms) in the user's home directory. On MacOS X, the default is called
'default.uaerc' instead since 'dot files' are not visible in Finder,
the OS X file manager.

You may tell E-UAE to load a configuration file in addition to the default by
passing the '-f' switch to E-UAE on the command line. Any options found in
this file will override the values of the same options in the default file.
The '-s' switch may also be used to specify a single <key>=<value> option on
the command line, which, again, will override options found in the default
file.

The default values for E-UAE's configuration options will cause E-UAE to
emulate a 68000-based ECS system with 512 KB of Chip memory and 512 KB of
Slow memory. The only option you absolutely need to specify is the path to
the Kickstart image you want to use (unless you wish to use E-UAE's minimal
Kickstart emulation, in which case you must instead supply the path to a
floppy disk image to boot from).

In the following descriptions of E-UAE's configuration options, the template
<n> refers to an integer value, <boolean> to a value of 'true' or 'false',
and <path> refers to a file path using whatever conventions the host platform
uses to specify paths.

This document is a work-in-progress.


General options
===============

The following options all have a prefix of the form <target>. The value of
<target> corresponds to the host platform on which you are running E-UAE.

  Target     Platform
  ------     --------
  amiga      AmigaOS (and clones such as AROS and MorphOS)
  beos       BeOS
  unix       Unix-like platforms - including Linux and Max OS X


<target>.rom_path=<path>

  Set the default path where Kernel ROM images may be found. The default is
  platform-dependent.

  Examples:

  unix.rom_path=/home/evilrich/UAE/roms/


<target>.floppy_path=<path>

  Set the default path where floppy disk images may be found. The default is
  platform-dependent.

  Examples:

  amiga.floppy_path=WORK:Apps/UAE/ADFs/


<target>.hardfile_path=<path>

  Set the default path where file-based hard disk images can be found. The
  default is platform-dependent.


use_gui=<boolean> (default=true)

  Open a configuration GUI at start-up before starting the emulation proper.
  This option is ignored on platforms without a configuration GUI or if
  E-UAE has been built without such a GUI.


use_debugger=<boolean> (default=false)

  Open the built-in debugger when the emulation starts. This option is
  ignored if E-UAE has been built without debugging support or if the
  debugger cannot be opened due to platform-specific restrictions (at
  the moment the debugger requires a terminal/console window, so it
  typically only works if you start E-UAE from a shell terminal).


Host CPU-specific options
=========================

x86.use_tsc=<boolean> (default=true)

  On x86 machines, if this option is true then the processor's timestamp
  counter will be used for timing in E-UAE. This used to be a problem for
  machines which did power-saving by scaling down the CPU's clock frequency,
  but with E-UAE 0.8.28 and above this should no longer be an issue on
  Linux. If you are running E-UAE on some other x86 platform which
  does frequency scaling, then set this option to false. Performance
  will suffer, but at least timing won't be affected by changes in CPU
  frequency.


amd64.use_tsc=<boolean> (default=true)

  Same as the option above, but applies to AMD64 processors.


ppc.use_tbc=<boolean> (default=true)

  On PPC machines, if this option is true then use the processor's timebase
  register for timing in E-UAE. Since the PPC's TBC isn't affected by
  frequency scaling, this option is of little use and is supported only for
  completeness. It may be useful if E-UAE misdetects or miscalibrates your
  machine's timebase frequency (if it does, please let me know).


CPU emulation options
=====================

cpu_type=<type> (default=68000)

  Select model of 68k processor to emulate. Valid values for <type> are
  68000, 68010, 68ec020, 68ec020/68881, 68020, 68020/68881, 68040 and 68060.

  Note:

  1) The values '68ec020' and '68ec20/68881' correspond to the 68020 model
     with a 24-bit address bus (as found in the A1200). Zorro III memory
     and/or a RTG graphics card cannot be emulated.
  2) The values '68ec020/68881' and '68020/68881' correspond to an 020 with a
     68881 floating point co-processor.
  3) The 68060 emulation is incomplete and not yet useful.


cpu_speed=<speed> (default=real)

  <speed> configures the performance of the interpretive CPU emulation
  relative to the Amiga chipset. This may have the value 'real', 'max' or
  can be an integer between 1 and 20.

  If set to 'real', E-UAE will try to emulate the performance of an original
  7MHz 68000-based Amiga such as an A500. That is, the relative balance of
  time spent emulating the CPU and the Amiga chipset will be similar to the
  performance of a real Amiga and E-UAE will try do the same amount of CPU
  work per display frame as a real 68000-based Amiga. Additionally, if
  any time is left over after emulating the A500's CPU and chipset in
  each display frame, then E-UAE will wait until until the next
  display frame is due.

  Thus, the setting 'real' is recommended for games designed to run on
  an A500-class Amiga but which won't work on faster Amigas. This includes
  many classic Amiga games.

  If set to 'max', the CPU emulation will run at the maximum speed that the
  host CPU can achieve. E-UAE will spend as much time as it can
  emulating the 68000 CPU and will not wait at all per frame.

  Integer values for <speed> adjust the relative amounts of time devoted to
  the CPU and custom chip emulations. Lower values increase the speed of
  the CPU emulation at the expense of the custom chips; higher values do
  vice-versa. Adjusting this value may allow better performance with some
  software. For example, when running Workbench on an RTG screen, better
  performance can be achieved from the interpretive emulation with a low
  value for 'cpu_speed'.


finegrain_cpu_speed=<n> (default=N/A)

  This option adjusts the relative speeds of the CPU and custom chip
  emulations just like supplying an integer value in cpu_speed= does, but it
  allows a more precise setting of the balance. The value <n> corresponds to
  the value supplied in cpu_speed= multiplied by 512.


cpu_compatible=<boolean> (default=false)

  If enabled, E-UAE will use a slower but more compatible version of the CPU
  emulation. This may be necessary to run some some demos and games
  correctly.

  This option currently only applies when emulating a plain 68000 CPU.


cpu_cycle_exact=<boolean> (default=false)

  If enabled, E-UAE will employ a CPU emulation which tries to fully
  emulate the relative timing of CPU and chipset cycles. This is much more
  demanding even than the "compatible" CPU emulation, but more accurate -
  and so may be necessary to correctly run software which aggressively uses
  the Amiga chipset.

  This option only applies when emulating a plain 68000 CPU.


JIT compiler options
====================

  The following options configure the dynamically-recompiling CPU emulation
  (or JIT compiler). The JIT engine translates 68k instructions for
  the Amiga CPU directly into instructions for the host CPU and caches
  these translated instructions in host memory. It's thus much faster
  than the interpretative emulation, but it may be less compatible
  with some software.

  Notes:

  1) The JIT is currently only supported on x86 host systems.

  2) Direct memory access in JIT compiled code (a method used to speed up
     memory access when using the JIT - this has nothing to do with hardware
     DMA) is currently only supported when hosting on x86 Linux.

  3) You must emulate a 68ec020 CPU or better to be able to use the JIT
     compiler.

  4) To enable direct memory access in compiled code, you must emulate a
     32-bit CPU, e.g., a full 68020, or a 68040.


cachesize=<n> (default=0)

  Use a cache of <n> KBs for storing code generated by the JIT compiler. If
  set to 0, the JIT compiler will be disabled. Setting this option between
  1024 and 8192 (i.e., 1 to 8 MB of cache) should allow the best performance.


compfpu=<boolean>

  If true, translate m68k FPU instructions to native FPU instructions.
  If false, interpret FPU instructions. Only applies if a CPU with a
  floating-point unit is selected.


Chipset options
===============

chipset=<type> (default=ecs_agnus)

  Specifies the model of Amiga chipset to emulate. Valid value for type are:

  Type           Description
  ----           -----------
  ocs            The original Amiga chipset, as found in the A1000, A500, etc.
  ecs_agnus      The OCS chipset, but with the ECS or "Fat" Agnus.
  ecs            The full ECS chipset, as found in the A500+ and the A600.
  aga            The AGA chipset, as found in the A1200 and A4000.


ntsc=<boolean> (default=false that is, PAL)

  If enabled, the NTSC variant of the chipset model is emulated. If
  disabled, the PAL variant is emulated.


immediate_blits=<boolean> (default=false)

  If enabled then blits performed by the Amiga chipset emulation will be
  reported as finishing immediately. This may improve performance at the
  price of compatibility. This option is ignored in cycle-exact mode.


collision_level=<type> (default=playfields)

  Specifies the level of collision-detection performed by the Amiga chipset
  emulation. Valid values for <type> are

  Type        Description
  ----        -----------
  none        No collision-detection is emulated.
  sprites     Sprite-to-sprite collisions are detected.
  playfields  Sprite-to-sprite and sprite-to-playfield collisions (that is
              collisions of sprites with the background) are detected.
  full        Full collision-detection (including collisions between the
              background and itself).

  The table above is ordered by the amount of work required to do the
  emulation. Thus, emulating just sprite-to-sprite collisions is faster
  than also emulating playfield collisions which is faster than full
  collision-detection.

  Full collision-detection is rarely required by software and much software
  (even games) will work with collision-detection disabled.


ROM options
===========

kickstart_rom_file=<path>

  The file path of a Kickstart ROM image to load. <path> may either be an
  absolute path or a path relative to the current directory when E-UAE was
  run. The token '$(FILE_PATH)' at the start of a path will be expanded to
  the path specified by the <target>.rom_path= option.

  If <path> is empty, E-UAE will use its built-in Kickstart emulation rather
  than a real  Kickstart image. This requires a valid floppy disk to boot
  from mounted in the emulated DF0: drive. The Kickstart emulation is
  sufficient to play many classic Amiga games.

  Examples:

  kickstart_rom_file=/home/evilrich/UAE/ROMs/kick130.rom
  kickstart_rom_file=../shared/roms/kick310.rom
  kickstart_rom_file=$(FILE_PATH)/kick.rom


kickstart_key_file=<path>

  Kickstart ROM images provided by Cloanto in its Amiga Forever
  distribution are encrypted. This option specifies the key file required
  to decrypt such an image. <path> may either be an absolute path to the ROM
  key file or a path relative to the current directory when E-UAE was run.
  The token '$(FILE_PATH)' at the start of a path will be expanded to the
  path specified by the <target>.rom_path= option.

  Examples:

  kickstart_key_file=~/rom.key


kickstart_ext_rom_file=<path>

  The ROM images required to emulate a CDTV or CD32 are available as two
  files: a standard image (loaded via the kickstart_rom_file= option above)
  and an 'extended' image.

  This option specifies the file path of an extended ROM image to load.
  <path> may either be an absolute path or a path relative to the current
  directory when E-UAE was run. The token '$(FILE_PATH)' at the start of a
  path will be expanded to the path specified by the <target>.rom_path=
  option.

  If E-UAE has been compiled without support for emulating the CDTV or CD32,
  then this option will be ignored.


cart_file=<path>

  The path of a cartridge ROM to load. This is used to load a ROM image
  from an Action Replay cartridge.


kickshifter=<boolean> (default=false)

  If enabled, the Kickstart ROM image will be patched after it is loaded into
  memory to support the running of Shapeshifter, the software-based classic Mac
  emulation for AmigaOS, within E-UAE.


RAM options
===========

chipmem_size=<n> (default=1, that is, 512 KB)

  Emulate <n> * 512 KB of Chip memory (memory that is accessible by the Amiga
  chipset). The valid range of values for <n> is between 1 and 16, that is,
  from 512 KB to 8 MB.

  Note that E-UAE must emulate an ECS ("Fat") Agnus to be able to use 1 MB
  of Chip memory or more. Also note that Fast memory cannot be used if you
  select more than 2MB of Chip memory.

  Example:

  chipmem_size=2

  would provide 1 MB of Chip memory.


bogomem_size=<n> (default=2, that is, 512 KB)

  Emulate <n> * 256 KB of "Slow" memory. The valid range of values for <n>
  is 0, 2, 4 and 7, that is 0 KB, 512 KB, 1 MB and 1.8 MB,
  respectively. If AGA emulation is enabled, then the maximum is 1 MB.

  "Slow" memory is the type of memory provided by the A500 trapdoor slot.
  It cannot be accessed by the Amiga chipset like Chip memory, but, unlike
  Fast memory, this memory cannot be accessed by the CPU when the custom
  chipset is busy - hence the term "Slow".

  Some old games and demos may require this type of memory. If E-UAE
  reports strange exceptions occuring when booting a floppy or weird
  accesses to custom chip registers, then try adding some "Slow" memory.
  Really old games may fail when "Slow" memory is added.


fastmem_size=<n> (default=0)

  Emulate <n> MB of Zorro II Fast memory. This is type of memory found on
  memory expansions cards for the A2000 and the A1200 trapdoor slot.


z3mem_size=<n> (default=0)

  Emulate <n> MB of Zorro III Fast memory.

  E-UAE must emulate a 32-bit CPU (a 68020 or better, not an 68ec020) to
  support the emulation of Zorro III memory.


gfxcard_size=<n> (default=0)

  Emulate an RTG graphics card with <n> MB of graphics memory. Selecting <n>
  greater than 0, enables the graphics card or so-called 'Picasso96'
  emulation. A maximum of 32 MB of graphics card memory may be emulated.

  E-UAE must emulate a 32-bit CPU (a 68020 or better, not an 68ec020) to
  support the graphics card emulation.


Floppy drive options
====================

In the following options, the template <drive> specifies the emulated drive
number. Up to four floppy drives may be emulated, numbered 0 to 3,
corresponding to the AmigaDOS devices DF0: to DF3:, respectively. Drive 0 is
the first drive, and drive in which you would typically insert a floppy disk
to boot from.

E-UAE supports file-based images of Amiga floppy disks in a number of
different file formats (see floppies.txt).


floppy<drive>=<path>

  Specifies the path of a floppy disk image to mount in drive DF<drive>:.
  <path> may either be an absolute path or a path relative to the current
  directory when E-UAE was run. The token '$(FILE_PATH)/' at the start of a
  path will be expanded to the path specified by the <target>.floppy_path=
  option.


floppy<drive>type=<type> (default=0 for drives 0 and 1, -1 for drives 2 and 3)

  Specifies the type of disk mounted in the emulated for drive DF<drive>:.
  <type> may have the following values

  Type    Disk type
  ----    ---------
  0       A 3.5" double-density disk. This is the disk type supported by
          standard Amiga floppy drives. Such disks have a capacity of 880 KB
          when formatted under AmigaDOS.
  1       A 3.5" high-density disk. This type of disk was supported by some
          add-on Amiga drives and in the drives shipped with some A4000s. A
          high-density disk formatted under AmigaDOS has a capacity of 1.76 MB.
  2       A 5.25" single-density disk. This disk type is for legacy
          compatibility and was rarely used by real Amigas.

  This option may also be set to -1 to disable the drive.


floppy_speed=<speed> (default=100)

  E-UAE's floppy drive emulation will work at <speed> per cent of a real
  Amiga floppy drive (relative to the speed of the rest of the emulation).
  Valid values are from '100' to '800', that is 1x to 8x the speed of a
  standard Amiga floppy drive.

  Setting 'floppy_speed=' to values other then 100 may affect compatibility
  with Amiga software, especially the floppy-based copy-protection systems
  included with some games.


Hard disk options
=================

  E-UAE may emulate hard drive partitions (AmigaOS volumes) or full,
  partitionable hard disks. Two basic types of emulation are supported: the
  virtual filesystem and the hard file.

  A virtual filesystem is a directory on the host system mounted as a
  virtual AmigaOS volume. The main advantages of a virtual filesystem are
  ease of use (no special setting-up is required) and the fact that both
  the host system and the emulated environment can access it at the same
  time (although this is not guaranteed to be safe, especially if host and
  emulated environment write to a directory simultaneously).

  A hard file is a file containing the raw image of a real AmigaOS
  filesystem or disk (an image of a partitionable disk is known as an "RDB"
  filesystem). A hard file is not so easy to set up, but provides faster
  access than a virtual filesystem and is more compatible with AmigaOS
  software (it can be formatted with any AmigaOS filesystem, de-fragmented,
  etc. just like a real Amiga partition). An RDB hard file can even be
  partitioned just like a real Amiga disk.


filesystem2=<access>,<device>:<volume>:<path>,<bootpri>

  Mounts the host directory specified by the path <path> as a virtual
  filesystem under AmigaOS with the volume name <volume> and a faked device
  name of <device>. The volume will have the boot priory <bootpri>. The
  token <access> specifies whether the volume is writable. If this is set
  to 'rw' then the device is writable; if it's 'ro' then the volume is
  read-only.

  Examples:

  filesystem2=rw,DH0:System:/home/evilrich/UAE/System,1

  Mounts the directory /home/evilrich/UAE/System as the volume 'System' and
  AmigaDOS device 'DH0:' with a boot priority of 1. This volume can be
  written to.

  filesystem2=ro,CD0:CD0:/cdrom,0

  Mount the host directory /cdrom as volume 'CD0:' and device 'CD0:' with
  boot priority 0. This volume may not be written to.


filesystem=<access>,<volume>:<path>

  This is an older and simpler form of the filesystem2= option.

  You can use both the filesystem2= and filesystem= options to specify the
  same volume (for instance, for compatibility with older versions of UAE),
  but the filesystem= option must be after the filesystem2= option in the
  config file.


hardfile2=<access>,<device>:<path>,<sectors>,<surfaces>,<reserved>,<blocksize>,<bootpri>,<handler>

  Mount the hard file (partition or drive image) <path>. The token <access>
  specifies whether the hard file is writable.  If it has the value 'rw',
  then the hard file is writable; if it is 'ro', then it's not writable.

  If the specified hard file is a partition image, then the partition will
  be mounted on the AmigaDOS device <device> (the volume name will be taken
  from the filesystem that the partition contains).

  For a hard file containing a partition image, the geometry of the
  partition must be specified.

  <sectors>   = the number of sectors per track
  <surfaces>  = the number of heads or surfaces on the disk (typically 1)
  <reserved>  = the number of reserved blocks at the start of the partition
                (typically 2).
  <blocksize> = the number of bytes per block (typically 512).

  <bootpri> specifies the boot priority of the volume.

  <handler> is optional and specifies a host path to locate the AmigaOS
  filesystem handler to use to mount this image. This option is useful when
  you wish to mount a volume that has been formatted with a filesystem not
  present in Kickstart - for example, SFS or PFS.


  If the specified hard file is an RDB hard file, that is, it's the image of
  a partitionable hard drive, you do not need to specify the geometry (the
  RDB - the Rigid Disk Block - in the hard file itself specifies the
  geometry). If <blocksize> is 0, then the hard file is assumed to be an RDB
  hard file. All other components of the hardfile2= option will be ignored
  apart from <path> and <access>.

  Examples:

  hardfile2=rw,DH1:/home/evilrich/myhardfile,32,1,2,512,1,

  hardfile2=rw,:/home/evilrich/rdbimage,0,0,0,0,0,


Display options
===============

The following options configure the emulation of native Amiga screenmodes
(displays generated by the built-in Amiga chipset - not of display generated
by Picasso96).

Todo: need some general blurb about how Amiga screens are output,
resolution, etc.


gfx_framerate=<n> (default=1)

  Specifies the rate at which display frames are rendered when emulating
  graphics output from the Amiga chipset. <n> can be a number between 1 and
  20, where 1 means that every display frame is rendered and 20 means only 1
  in every 20 frames is rendered.

  Increasing <n> increases the speed of emulation (there's less work to
  do), but decreases the quality of the display output.

  For example, when emulating a PAL display (50 Hz), for full-quality output
  (gfx_framerate=1), E-UAE must update its display 50 times a
  second. Setting gfx_framerate=4 will cause E-UAE to draw only 1
  frame in 4 and thus its display will updated only 12.5 times a second.


gfx_width_windowed=<n> (default=720)
gfx_height_windowed=<n> (default=568)
gfx_width_fullscreen=<n> (default=800)
gfx_height_fullscreen=<n> (defaullt=600)

  Specify the dimensions of the E-UAE display for graphical output from the
  Amiga chipset.

  Ideally, the gfx_*_windowed options should specify the dimensions when
  E-UAE is running in a window on your desktop and the gfx_*_fullscreen
  options will apply when running full-screen. However, this is not supported
  yet, and E-UAE will use the gfx_*_windowed dimensions in both windowed and
  full-screen modes.

  To emulate a high-resolution, fully overscanned PAL screen - either
  non-interlaced with line-doubling, or interlaced - you need to use a
  display of at least 720 by 568 pixels. If you specify a smaller size,
  E-UAE's display will be clipped to fit (and you can use the gfx_center_*
  options - see below - to centre the clipped region of the display).
  Similarly, to fully display an over-scanned lo-res PAL screen, you need a
  display of 360 by 284 pixels.


gfx_width=<n>
gfx_height=<n>

  These option are for backwards-compatibility and have been superceded by
  the gfx_*_windowed and gfx_*_fullscreen options above.


gfx_fullscreen_amiga=<bool> (default=false)

  E-UAE will open it's display for Amiga screens in full-screen mode by
  default - not as a window on the desktop.

  This option is not supported on all platforms.


gfx_lores=<boolean> (default=false)

  Determines the fundamental horizontal resolution of output. If true, then
  E-UAE will emulate a low-resolution output; high-res Amiga screens will
  have their horizontal resolution halved (only every other horizontal pixel
  will be drawn). If false, E-UAE will emulate a high-resolution output;
  low-resolution Amiga screens will have their horizontal resolution doubled.

  Most classic games employ low-resolution screens; Workbench uses a
  high-resolution screen by default.


gfx_linemode=<type> (default=double)

  Determines how many times each display line is drawn. Valid values for
  <type> are:

  Type       Description
  ----       -----------
  none       Each line is drawn once.
  double     Each line is drawn twice.
  scanlines  Each line is drawn once followed by an black line.


gfx_correct_aspect=<boolean> (default=false)

  If set to true and the emulated Amiga screen has a larger vertical size
  than the display window, E-UAE will fit the screen to the display by
  leaving out certain lines. This is useful, for example, if you wish
  to fit a 640x512 Amiga screen into a 640x480 window.

  Don't use the option with gfx_linemode=scanlines. It'll look ugly.


gfx_center_horizontal=<type> (default=none)

  If the Amiga screen emulated is wider than the E-UAE display, then this
  option will try to cause the screen to be rendered centred on the display.

  Type           Description
  ----           -----------
  false/none     No centring will be performed.
  true/simple    Simple centring will be performed.
  smart          Smart centring will be performed.


gfx_center_vertical=<type> (default=none)

  Similar to gfx_center_horizontal, but centres the screen vertically within
  the E-UAE display.


show_leds=<bool> (default=false)

  If true, show drive activity and power LEDs at the bottom right corner of
  the E-UAE display.


hide_cursor=<bool> (default=true)

  If this option is set to true and E-UAE is displaying in windowed mode,
  then the host window manager's cursor is hidden; otherwise it is shown.
  This option may not be implemented on all platforms yet.


Sound options
=============

sound_output=<type>

  Selects how native Amiga audio is emulated and output. Supported values
  for <type> include:

  none       - audio emulation is disabled.
  interrupts - audio emulation is enabled but audio output is disabled.
  normal     - audio emulation is enabled and output enabled.
  exact      - audio emulation is enabled and exact output enabled.


sound_bits=<n>

  Selects the resolution of audio output. <n> can be 8 or 16 for 8-bit and
  16-bit output, respectively. Most hosts will use 16-bit output and this
  will be the default.


sound_frequency=<n>

  Selects the frequency of emulated audio output in Hertz. Typically,
  higher frequencies will require more work, but have better quality. The
  default is dependent on the host audio system used, but most will default
  to 44100 Hz (that is, CD-quality output).

  Typical values for <n> include 11025, 22050 and 44100.


sound_channels=<type>

  The Amiga supports 4-voice stereo sound, with two channels output on the
  left channel and two on the right. This option selects how the Amiga's
  voices are output on the host audio system. Supported values for <type>
  are:

  mono   - monophonic output; all Amiga voices are output on a single channel.
  stereo - stereo output; two Amiga voices are output on the left channel and
           two on the right.
  mixed  - stereo output; the four Amiga voices are mixed and output on both
           left and right channels.


sound_latency=<t> (default=100)

  Specifies the length of the audio buffer used by the audio emulation in
  microseconds independent of the other audio settings, and, hence, also the
  time lag between when a sample is played in the emulated Amiga environment
  and in the underlying host sound system (thus 'latency').

  The default value of 100 ms attempts to strike a balance between
  acceptable latency and CPU usage. Larger values of <t> may require less
  CPU time and lead to fewer drop-outs (gaps) in audio emulation, but will
  suffer increased latency (a latency of more than about 150ms becomes very
  noticeable). Smaller values will require more CPU power but reduce latency.

  Note that not all host sound systems will support arbitrary values of <t>.
  For example, the Open Sound System will round the supplied value to one
  that corresponds to the nearest power-of-2 audio buffer size.


sound_max_buff=<n>

  From E-UAE 0.8.29, this option is obsolete and has been replaced by the
  option sound_latency.


sound_interpol=<type> (default=none)

  Selects the sound interpolation mode used for audio output (only supported
  when audio output is in 16-bit resolution). Interpolation is a technique
  which "smoothes out" the audio waveform generated by E-UAE and thus may
  lead to higher quality audio output. Supported values for <type> are:

  none - no interpolation.
  rh   - 'rh' method of interpolation is used.
  crux - 'crux' method of interpolation is used.
  sinc - 'sinc' meethod of interpolation is used.


Input device options
====================

joyport0=<mode>

  Selects the method used to emulate the device attached to the Amiga
  joystick port 0 (the mouse port).

  none  - no device is connected to this port.
  mouse - a mouse will be emulated on this port and input will be supplied
          from the host's default mouse (the device you use to move the
          mouse pointer on the host).
  joy0  - a joystick will be emulated on this port and input will be supplied
          from the first joystick found on the host.
  joy1  - a joystick will be emulated on this port and input will be
          supplied from the second joystick found on the host.
  kbd1  - a joystick will be emulated using the numeric keypad (8, 2, 4 and
          6 are directions up, down, left and right, respectively, and 5 is
          the fire button).
  kbd2  - a joystick will be emulated using the cursor keys and the Right Ctrl
          key or Right Alt key for the fire button.
  kbd3  - a joystick will be emulated using the keys T, B, F and H for up,
          down, left and right, respectively, and the Left Alt key for the
          fire button.


joyport1=<mode>

  Selects the method used to emulate the device attached to the Amiga
  joystick port 1 (the joystick port). Supported values for <mode> are the
  same as for the joyport0= option.


SCSI emulation options
======================

E-UAE can provide direct access to a host optical drive like a CD-ROM drive
to AmigaOS via an Exec device wrapper called uaescsi.device. The SCSI device
emulation is not supported on all platforms. See the SCSI emulation section
of the documentation for more details.

scsi=<bool> (default=false)

  Enable or disabled the SCSI emulation.


scsi_device=<config>

  This option is used for passing a platform-specific configuration to the
  SCSI emulation layer.


Network emulation
=================

E-UAE can provide network access to AmigaOS applications via an emulated
bsdsocket.library. This emulated bsdsocket.library is simply a wrapper
around the host's networking stack. The AmigaOS environment within E-UAE
will share the same IP address as the host. The bsdsocket.library emulation
is not supported on all platforms. See the bsdsocket emulation section of
the documentation for more details.

bsdsocket_emu=<bool> (default=false)

  Enable or disable the bsdsocket.library emulation.


X11-specific options
====================

The following options apply when E-UAE has been built with the X11 graphics
driver.

x11.map_raw_keys=<bool> (default=false)

  If true, the X11 driver maps raw host key codes to Amiga key codes;
  otherwise, the driver tries to map translated key codes, possible leading
  to poorer support for international keyboard layouts (see
  docs/keyboard.txt).

  For raw key-mapping to be supported, your X server must support the XKB
  extension. Also note that X keyboards that generate xfree86 key codes
  (typicallying PC and Mac keyboards with XFree86 or X.org servers) only are
  supported at the moment.


x11.low_bandwidth=<bool> (default=false)

  If this option is set to true, then E-UAE will try to minimize the amount
  of data sent to the X server by only redrawing areas of the amiga screen
  that have changed. This may increase frame rate on slow machines or when
  running E-UAE on a separate host from the X server.


x11.use_mitshm=<bool> (default=true)

  If this option is set to true, your X server supports the MITSHM extension
  and E-UAE is running on the same host as the server, then E-UAE will use
  memory shared between itself and the server for display buffers. This will
  increase display refresh speed.


x11.hide_cursor=<bool>

  Deprecated. This option has been replaced by hide_cursor=<bool>.


SDL-specific options
====================

The following options apply when E-UAE has been built with the SDL graphics
driver.

sdl.map_raw_keys=<bool> (default=false)

  If true, the SDL driver maps raw host key codes to Amiga key codes;
  otherwise, the driver tries to map translated key codes, possible leading
  to poorer support for international keyboard layouts (see
  docs/keyboard.txt).

sdl.use_gl=<bool> (default=false)

  If true, the SDL driver uses OpenGL for display output. Depending on your
  OpenGL driver this may increase or decrease the speed of emulation.
  Note: This setting does not enable a OpenGL emulation for Amiga (e.g. Warp3D)
  but simply uses an OpenGL texture for the 2D Amiga and Picasso96 display.

AmigaOS-specific options
========================

The following options apply when E-UAE has been built for AmigaOS (or
similar platform) with the AmigaOS graphics driver.

amiga.screen_type=<type> (default=public)

  Specifies the type of screen that E-UAE will open it's display on. Valid
  values for <type> are:

  Type     Description
  ----     -----------
  public   The display will be a window on the default or named public
           screen.
  custom   E-UAE will open a custom screen for its display. The best
           screenmode matching the configured dimensions will be used.
  ask      E-UAE will present you with a requester to select the screenmode
           to use for display. If this requester is cancelled, E-UAE will
           use a window on the default or named public screen.


amiga.publicscreen=<name>

  Specifies the name of the public screen to open a window on. If <name> is
  empty, the default public screen will be used.


amiga.use_dither=<bool> (default=true)

  When displaying on a palette-mapped screen (that is, a screen with depth
  of 8 or less), dither output to compensate for lack of colour.


amiga.use_grey=<bool> (default=false)

  When displaying on a palette-mapped screen (that is, a screen with depth
  of 8 or less), output in greyscale rather than colour. This option is
  particularly useful when displaying on a public screen with few free pens.


ALSA-specific options
=====================

The following options apply when E-UAE has been built with the ALSA audio
driver.

alsa.device=<device> (default=default)

  Specifies the ALSA device to output to. The default value is 'default',
  which obviously uses the default ALSA PCM device. On recent ALSA
  installations, this may use ALSA's dmix plug-in (the dmix plug-in allows
  multiple applications to share an ALSA device for output) which may result
  in unacceptable latency and/or increased CPU load. If that is the case,
  add the option 'alsa.device=plughw:' to by-pass the dmix plug-in.

  See the libasound documentation for full details on how to specify ALSA
  devices.


alsa.verbose=<bool> (default=false)

  If this options is set to true, the ALSA driver will log additional
  information about how it configures the specified ALSA device. This may
  help to diagnose problems with ALSA configuration, etc.