Quote Originally Posted by f_lez
I changed the chip type to 2550 in MCS, copied the usb support files into my pbp directory, and compiled..
Did you read the USB.TXT file?
They don't go in the PBP folder. They go in your project's folder.
Now you've messed up the .bas files for all the USB chips, and will have to restore them from the CD or a backup.

Did you modify the USBDESC.ASM file to point to the CDC descriptors?

Do you have a .22uF or higher capacitor on VUSB?

Are your configs set for a 4Mhz crystal, with USB regulator enabled?
Code:
ASM
        __CONFIG    _CONFIG1L, _PLLDIV_1_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
        __CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H
        __CONFIG    _CONFIG2L, _PWRT_ON_2L & _BOR_OFF_2L & _VREGEN_ON_2L
ENDASM
And restore the program back to what it was originally (download it again).
It won't work the way you've modified it.