IIRC, IBM liked to refer to them as planar boards... On Thu, Oct 15, 2015 at 2:34 PM, Mark Linimon <linimon at lonesome.com> wrote: > On Thu, Oct 15, 2015 at 10:18:46AM -0700, Fred Cisin wrote: > > Wasn't the B5900 from 1980? > > Hmm. I guess my mind put "B5500" for "B5900". > > mcl >