Don, I realize that this is your contest so you get to set the rules, but I question your definition of "fastest".
Here are the results of running the solutions on a z10-EC: 1) Glen Herrmannsfeldt 0.127 microseconds 2) Fritz Schneider 0.254 microseconds 3) Don Higgins 0.452 microseconds 4) Melvyn Maltz 8.102 microseconds Glen's solution requires the string to be padded with X'00' until the length is a multiple of 8. I think this is cheating a bit. But proper handling of the last 1 to 7 bytes would probably still keep his solution in first place. Melvyn's solution suffers horribly on a real machine because it is self-modifying. Replacing the MVC and ASI instructions with IC and AR moves his solution back into third place with a time of 0.366 microseconds. David
