FWIW - I posted this comment to the board... Bruce, Thanks for doing this. When I wrote a78sign, I was interested in understanding the crypto techniques that were used. That's why I started from scratch with a crypto library, and attempted to document the algorithm in the code, rather than blindly converting the 68K program. I had partially converted a78sign to vanilla python a while back, but never finished the file parsing part (the crypto works though). If someone wants the code I can dig it up. At any rate, you can build a78sign for Linux and Mac, although no-one ever bothered too. If there is still a demand I can build it for Linux. Thanks, Frank