Monkey 64 HOWTO ***Read First***
1. Make a folder on the root of your memorystick called "N64".
2. Make sure the rom you have is unzipped. For example the filename should be something like "WaveRace64.v64".
3. Take that file and put it into the folder called "N64" which is on the root of your memorystick.
4. Now place Monkey64 in your game folder.
For people with 1.0 or people using eloader your memorystick should look like this:
E:\N64
E:\PSP
E:\PSP\GAME
E:\PSP\GAME\Monkey64
For people with 1.5 your memorystick should look like this:
E:\N64
E:\PSP
E:\PSP\GAME
E:\PSP\GAME\Monk _
E:\PSP\GAME\Monk_~1%
Now... start up the emulator, and then you should come up to something that says this:
( ) load rom -> WaveRace64.v64
( ) clock speed
etc...
Make sure that the "0" between the parentheses is in "load rom" section and press "X". The light should flicker a couple of times and when it stops go down to "Run Rom" and press "X" again.
Congratulations you are now emulating the N64 on your PSP (well, sorta).
Parts of this guide taken from PSPdemon. :)