My question is about PIC-USB-4550 demo board. For what IDE is the Olimex blinking LED c program at: https://www.olimex.com/Products/PIC/Proto/PIC-USB-4550/
Can someone help with a version for MPLABX?
Well, if you can't compile it, it is not because of MPLABX, but because of the compiler. If you wish to compile that example successfully you need to use the same old compiler that we did when we wrote it (MCC18 v3.47). We've rebuild the project today you can find build info file inside with link to compiler and environments we tested:
https://ftp.olimex.com/Lub-clients/PIC-USB-4550-BLINKING_LED.zip