Supposedly according to the microchip site, if you go to datasheet finder and put in 18f4550, and you go to supported developement tools, there is the picstart listed with "supported" underneath it in the table.. I thought I remembered that it did not support it. andrew -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist