On Tue, 28 Jan 2014 10:23:57 -0700 Dwayne Reid wrote: > Many, many thanks, Jason. >=20 > I'm in a similar boat as John - I don't yet 'Grok' C (and I'm not=20 > competent with Microchip's Linker) - and simply don't know where to=20 > turn when cryptic error messages show up. Jason: Thanks. Though I have no experience programming C on PICs I did solve quite a few quirks in the bootloader to get it to compile with the xc8 compiler in Linux. Except for the data memory issue. Which was the only error which appeared originally when compiling with xc8 in mcc18 compatible mode. I did look around for the messages and I did find messages about the memory problems, but, as I don't know the original code, I wasn't sure I would be able to solve the problem. Particularly the xc8 manual is very unhelpful, as are the messages.=20 The C-version should work with the 18f2550 - it was written for that processor after all. I suspect that some variables have changed=20 size in xc8 as compared to the original picc18 compiler.=20 I was also able, after a very long and painful process, to compile the Mchip bootloader in MPLAB X. But the learning curve to MPLAB X is huge. Doing simple projects are just way to complicated. Even MPLAB installation was a very painful process. The assembly version is working fine, after some minor quirks, such as inverted logic, which I resolved in no time. I can upload=20 programs and they work... I don't even have to install an USB stack, a couple of hooks let me re-use the bootloader code for simple projects. John --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .