To all with interest in IBM 7090

{begin pedantry} I'll butt in and say, yes twinax is serial, but no not in a RS232 serial terminal way. Twinax (twin-axial) only describes the cabling infrastructure. Normally twinax networking refers to an IBM specific workstation infrastructure common to their mid range before the ubiquitity of TCP/IP. The protocol was block mode rather than character. The transmission is serial based I believe, but not RS232 compliant. The signalling is compatible with twisted pair, as well as the twin core coaxial cable from which the whole communication infrastructure typically nicknamed. The protocol is typically referred to as 5250 after the original workstation model. But unlike typical serial comms, it is a bus topology. So not really an intersecting set in a meaningful compatibility kind of way.{end pedantry} ard at p850ug1.demon.co.uk wrote: -- Colin