Go ahead. The Debian S/390 installer is almost a friendly penguin so you should be okay. The Debian S/390 port installation guide says "Since Debian Squeeze, support for booting in ESA/390 mode was dropped. Your machine needs to support for at least the z/Architecture, Architecture Level Set 2." I take this to mean that Debian no longer runs on a real S/390 machine but requires a zSeries of some sort. Does that work with Hercules? Bob