Settings for DOSBox are stored in the dosbox.conf file. Some of the options (such as cycles) can be changed on the fly through batch files, while others (like mouse sensitivity, output method) will only take effect if the dosbox.conf file is edited directly.

memsize defines the amount of available RAM in megabytes. The PSP 1000 ("fat") is limited to around 12; owners of later models may try higher values (up to around 44).

Setting core=dynamic boosts performance for most games, but the additional speed may come at the cost of stability.

The cycles settings are the single most important determinant in how well the game will run. Some games will actually play better with lower cycle settings; getting the right one is a trial-and-error process. cycles=max isn't the highest possible cycle setting, despite the name; cycles above ca. 7'000 will push the game faster than max.

A detailed explanation of all the parameters is available on the DOSBox wiki.

Template for the dosbox.config file

[sdl]
# fullscreen -- Start dosbox directly in fullscreen.
# fulldouble -- Use double buffering in fullscreen.
# fullresolution -- What resolution to use for fullscreen: original or fixed size (e.g. 1024x768).
# windowresolution -- Scale the window to this size IF the output device supports hardware scaling.
# output -- What to use for output: surface,overlay,opengl,openglnb,ddraw.
# autolock -- Mouse will automatically lock, if you click on the screen.
# sensitiviy -- Mouse sensitivity.
# waitonerror -- Wait before closing the console if dosbox has an error.
# priority -- Priority levels for dosbox: lowest,lower,normal,higher,highest,pause (when not focussed).
#             Second entry behind the comma is for when dosbox is not focused/minimized.
# mapperfile -- File used to load/save the key/event mappings from.
# usescancodes -- Avoid usage of symkeys, might not work on all operating systems.
# keyhint -- When set to true, the first button press will display a hint about what
#            key you will get with the second button press.
#            If the key you want isn't there you can cancel by pressing cross.

fullscreen=false
fulldouble=false
fullresolution=original
windowresolution=480x272
output=overlay
autolock=true
sensitivity=40
waitonerror=true
priority=higher,normal
mapperfile=mapper.txt
usescancodes=true
keyhint=true
irkeybini=pspirkeyb.ini

[dosbox]
# language -- Select another language file.
# memsize -- Amount of memory dosbox has in megabytes.
#                          PSP Fat: max ca. 12 MB; PSP Slim: ca. 44 MB.
#                          Higher values possible, but will cause instability.
# machine -- The type of machine tries to emulate:hercules,cga,tandy,pcjr,vga.
# captures -- Directory where things like wave,midi,screenshot get captured.

language=
machine=vga
captures=capture
memsize=12

[render]
# frameskip -- How many frames dosbox skips before drawing one.
# aspect -- Do aspect correction, if your output method doesn't support scaling this can slow things down!.
# scaler -- Scaler used to enlarge/enhance low resolution modes.
#           Supported are none,normal2x,normal3x,advmame2x,advmame3x,hq2x,hq3x,
#                         2xsai,super2xsai,supereagle,advinterp2x,advinterp3x,
#                         tv2x,tv3x,rgb2x,rgb3x,scan2x,scan3x.
#           If forced is appended (like scaler=hq2x forced), the scaler will be used
#           even if the result might not be desired.

frameskip=0
aspect=false
scaler=none
invert=false

[cpu]
# core -- CPU Core used in emulation: normal,simple,dynamic,auto.
#         auto switches from normal to dynamic if appropriate.
# cycles -- Amount of instructions dosbox tries to emulate each millisecond.
#           Setting this value too high results in sound dropouts and lags.
#           You can also let DOSBox guess the correct value by setting it to max.
#           The default setting (auto) switches to max if appropriate.
# autocycle --  This will adjust the cycles by attempting to match the emulated 
#           vsync with the actual one. This works well with games that run at 
#           or nearly full speed.
# cycleup     -- Amount of cycles to increase/decrease with keycombo.
# cycledown      Setting it lower than 100 will be a percentage.

core=normal
cycles=auto
autocycle=true
mincycles=600
maxcycles=2000
cycleup = 500
cycledown = 500

[mixer]
# nosound -- Enable silent mode, sound is still emulated though.
# rate -- Mixer sample rate, setting any devices higher than this will
#         probably lower their sound quality.
#         Possible values: 22050, 44100, 48000, 32000, 16000, 11025, 8000, 49716.
# blocksize -- Mixer block size, larger blocks might help sound stuttering
#              but sound will also be more lagged.
#              Possible values: 2048, 4096, 8192, 1024, 512, 256.
# prebuffer -- How many milliseconds of data to keep on top of the blocksize.

nosound=false
rate=22050
blocksize=2048
prebuffer=500

[midi]
# mpu401      -- Type of MPU-401 to emulate: none, uart or intelligent.
# device      -- Device that will receive the MIDI data from MPU-401.
#                This can be default,alsa,oss,win32,coreaudio,none.
# config      -- Special configuration options for the device. In Windows put
#                the id of the device you want to use. See README for details.

mpu401=intelligent
device=default
config=

[sblaster]
# sbtype -- Type of sblaster to emulate:none,sb1,sb2,sbpro1,sbpro2,sb16.
# sbbase,irq,dma,hdma -- The IO/IRQ/DMA/High DMA address of the soundblaster.
# mixer -- Allow the soundblaster mixer to modify the dosbox mixer.
# oplmode -- Type of OPL emulation: auto,cms,opl2,dualopl2,opl3.
#            On auto the mode is determined by sblaster type.
#            All OPL modes are 'Adlib', except for CMS.
# oplrate -- Sample rate of OPL music emulation.

sbtype=sb16
sbbase=220
irq=7
dma=1
hdma=5
mixer=true
oplmode=auto
oplrate=22050

[gus]
# gus -- Enable the Gravis Ultrasound emulation.
# gusbase,irq1,irq2,dma1,dma2 -- The IO/IRQ/DMA addresses of the 
#            Gravis Ultrasound. (Same IRQ's and DMA's are OK.)
# gusrate -- Sample rate of Ultrasound emulation.
# ultradir -- Path to Ultrasound directory.  In this directory
#             there should be a MIDI directory that contains
#             the patch files for GUS playback.  Patch sets used
#             with Timidity should work fine.

gus=false
gusrate=22050
gusbase=240
irq1=5
irq2=5
dma1=3
dma2=3
ultradir=D:\ULTRASND

[speaker]
# pcspeaker -- Enable PC-Speaker emulation.
# pcrate -- Sample rate of the PC-Speaker sound generation.
# tandy -- Enable Tandy Sound System emulation (off,on,auto).
#          For auto Tandysound emulation is present only if machine is set to tandy.
# tandyrate -- Sample rate of the Tandy 3-Voice generation.
# disney -- Enable Disney Sound Source emulation.

pcspeaker=true
pcrate=22050
tandy=auto
tandyrate=22050
disney=true

[joystick]
# joysticktype -- Type of joystick to emulate: auto (default), none,
#                 2axis (supports two joysticks), 4axis,
#                 fcs (Thrustmaster), ch (CH Flightstick).
#                 none disables joystick emulation.
#                 auto chooses emulation depending on real joystick(s).
# timed -- enable timed intervals for axis. (false is old style behaviour).
# autofire -- continuously fires as long as you keep the button pressed.
# swap34 -- swap the 3rd and the 4th axis. can be useful for certain joysticks.
# buttonwrap -- enable button wrapping at the number of emulated buttons.

joysticktype=2axis
timed=false
autofire=false
swap34=false
buttonwrap=true

[serial]
# serial1-4 -- set type of device connected to com port.
#              Can be disabled, dummy, modem, nullmodem, directserial.
#              Additional parameters must be in the same line in the form of
#              parameter:value. Parameter for all types is irq.
#              for directserial: realport (required), rxdelay (optional).
#              for modem: listenport (optional).
#              for nullmodem: server, rxdelay, txdelay, telnet, usedtr,
#                             transparent, port, inhsocket (all optional).
#              Example: serial1=modem listenport:5000

serial1=dummy
serial2=dummy
serial3=disabled
serial4=disabled

[dos]
# xms -- Enable XMS support.
# ems -- Enable EMS support.
# umb -- Enable UMB support.
# keyboardlayout -- Language code of the keyboard layout (or none).

xms=true
ems=true
umb=true
keyboardlayout=none

[ipx]
# ipx -- Enable ipx over UDP/IP emulation.

ipx=false

[autoexec]
# Lines in this section will be run at startup.
SYSOPT clock 333

@INPUTMAP analog mouse
@INPUTMAP cross enter

mount c ./
C: