I've been trying (without success) to crack the encryption scheme that Gemstar uses in its' VCRplus codes. I have written a TV/cable show management system that generates plus codes for half-hour boundary shows (ie 4 to 6 digit codes). I can't seem to find anything on 7 and 8 digit codes which handle 5 minute increments for program start time and length. (And yes, I have the article "Decoding a VCR Controller Code" by Ken Shirriff, Curt Welch and Andrew Kinsman. It was published in Cryptologia. Unfortunately, they didn't get beyond 6 digits either.) BTW, this is strictly for my own use. I'm just tired of approximating shows and also a bug that I have that occasionally gives incorrect results (I think it may be a leading zero being trimmed by the math formulas). Can anyone help?