Hi everybody I know there was a recent discussion of this topic on the Piclist, but at the time I didn't really pay much attention and now I whish that I did! :( I wanted to upgrade to MPLAB v3.10 because this was supposed to support my newly aquired PCB & PCM C compilers from CCS. Only now that I upgraded, I find that I can't communicate with the PICSTART Plus programmer anymore. I am using the recommended Picstart plus software v1.20.07. Does anybody else have the same problem, or is my Picstart Plus programmer faulty? I know there is also an upgrade hex file available from the Microchip website for upgrading the firmware, but I assumed this was only neccessary if you wanted your programmer to support all the latest hardware. Will my problems dissapear if I buy a new 17C44 and upgrade my firmware? I'm going to try and go back to my previous version of MLAB V3.01 now, because version 3.09 is no longer available from Microchip's website. Hopefully my programmer will start to work when I do this, but this seems to be my only hope.... or is it? Regards Werner PICSTART Plus v1.20.07 requires MPLAB v3.10 or greater. PICSTART Plus v1.20.07 will not work with older versions of MPLAB, and MPLAB v3.10 will not work with older versions of PICSTART Plus. These versions include compatibility checks to ensure that version requirements are met. -- Werner Terreblanche Tel +27 21 7102251 Fax +27 21 721278 wterreb@plessey.co.za (work) OR werner@aztec.co.za (home)