Andrew Warren wrote: > .... > Now let's do the math for your "parity bit for each data bit" > solution: Each bit has an error rate of 0.01%, so the error rate for > the whole packet will be approximately 0.32%. > ... I haven't looked at all the maths, but this is not right. You start assuming 99% okay bits, then say 0.01% change of error in a bit, not 1%. If 1% chance of error in a bit, then 32 bits has 27% change of error (1-0.99^32). Admittedly for a 0.01% error, 32 bits is about 0.3195% error rate... -- _ (_) _| _ . _ _ Tel +44 973 222257 Nokia orange in stock *NOW*. E&OE ( )(_|( |(_|| ) Fax UK 0500 222258 http://www.eaglenet.co.uk/aa/