RX02 and intel hex file tools

Well, if "things like perl" means "anything with enough generality to recompute checksums", that becomes..uninteresting. :) If it means something more like "Turing-complete languages", it's not much more interesting. But if you're willing to accept a bti of awk, it's doable. I'd probably do something like ...the record... | sed -e 's/../& /g' | cvtbase X d | awk '{sum += $1;} END {printf("%02x\n",255-(sum%256));}' mutatis mutandis if the checksum algorithm is more complicated than a simple "all bytes sum to 0x00". Inserting the resulting checksum into the record is left as an exercise for the reader. (cvtbase is my own, but as used here just converts 0-9A-F hex to decimal; I believe you can do that with dc or bc or some such instead. Or you can pick up ftp.rodents.montreal.qc.ca:/mouseware/hacks/cvtbase.c. :) /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B