Team Xboxopensource has released the Apple II Portable emulator for PSP. Apple II Portable is a homebrew application which will emulate the Apple II on your PSP. The information about this emulator is:

Feature Log

imported YAE 0.6 sources
16:9, 4:3 ratio displays & overscanned displays
disk swapping
40 & 80 column text modes (slot 3 80 col card)
two DiskII drives, prodos and dos 3.3 compatible
II, II+ and IIe emulation
hard (memory clearing) reset
Currently Known Bugs

exit occasinally crashes
video texture issues
timing issues
sound quality issues (related to timing)
To-Do List

smartport disks (400k, 800k, harddisks)
mockingboard emulation
realtime clock
midi card
printer emulation (epson mx-80)
Uther Ethernet emulation over wifi (for contiki)
uber secret things
Controls

DPAD/Analog : Joystick 0
cross circle triangle : Button 0, 1, 2
L trigger : onscreen keyboard
Start : main menu
Select : disk menu