IR Keyboards are supported by DOSBox for PSP (on the 1000 model only, as newer editions lack an IR port). The keyboard configuration file is named pspirkeyb.ini, which should be placed in the same folder as the EBOOT.

pspirkeyb.ini

#
# pspirtty keyboard driver
#

[KEYBOARD]
mapfile_dir = 'ms0:/seplugins/keymap';
# change this to your needs
map = 'targus.ini';
# change this to your needs
keyboard = 15;
# number of calls that fail to return a new key before last key repeats
delay = 50;
# number of calls that fail to return a new key between key repeats
rate = 10;

##############################
# possible "keyboard" values #
##############################
#
# 0  - NO keyboard
#
# 1  - Compaq/HP foldable keyboard
# 2  - Snap'n'Type
# 5  - HP Slim keyboard
# 8  - Belkin IR (not IrDA)
# 9  - Flexis FX-100 keyboard
# 10 - Benq G250 gamepad
# 11 - Micro Innovation Pocketop keyboard
# 12 - Micro Innovations Foldaway keyboard
# 13 - Micro Innovations Datapad
# 14 - Compaq MicroKeyboard
# 15 - Targus Universal Wireless keyboard
# 18 - Freedom keyboard
# 19 - NOVAETS - KIS2 - IR Keyboard
# 20 - Palm Universal Wireless Keyboard
# 21 - Hama Palm IR keyboard
# 22 - Sprint PDA Keyboard