Hi Chris, I once spent almost a month trying to figure out what was wrong with an embedded computer system based on a 68000 processor, only to find out eventually that my project partner and I had different definitions of "upper" and "lower" when it came to the two 8-bit wide flash chips which formed the 16-bit wide program memory for the processor. I would program them using a homebrew flash programmer and then hand them to him as the "upper" and "lower" ICs. I took this to mean upper and lower significance, he took it to mean upper and lower address. In other words, it was an endian problem. However, I was a high-school senior working with almost no test equipment - we eventually built a logic analyzer out of a FIFO chip and discovered that the processor was fetching every instruction in inverted byte order and we suddenly realized what was happening. We swapped the two flash chips and it immediately ran most of the code properly. I think this is a mistake that anyone can make, but I wouldn't write an article about it for a trade journal and I would be concerned if it took a professional engineer a month to figure it out, especially an engineer who is working on military radar jamming equipment! Sean On Sat, Oct 2, 2010 at 5:11 PM, Chris McSweeny wrote= : > I'm loving all the smugness on this thread. Presumably nobody on here > has ever made a silly mistake? > > Chris > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .