I can't remember exactly, but the 100A was definitely 4.xx series (maybe 4.12?) while the 100B was definitely 5.xx series (maybe 5.03A). I've never seen different values on any Rainbow, though, suggesting that the boot roms were finalized before manufacturing started and never again updated. Could be wrong, though. Some Rainbow's have different character set ROMs, like the Technical Character Set ROM, but that doesn't change the firmware version on the boot menu. -Jeff jba at sdf.lonestar.org SDF Public Access UNIX System - http://sdf.lonestar.org