> It may worth to try the switch case structure that should compile to > something similar to the jump table in your example: Hi Tam=E1s, It may... but it won't fix the bug in my implementation :( My code throws away a carry. Instead, the rotates need to operate on 7 incoming bytes to produce 8 output bytes. There's a straight forward way to do this, and if I get the time I will. The basic approach is valid. Scott -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist