On Apr 4, 2013, at 5:18 PM, <hvlems at zonnet.nl> wrote: Apparently not. The reason I came up with the device is that I used a PDP 11/40 with a DU11 to connect to a Burroughs B7700 using an RJE like protocol. It was called SYSTEM/SATCOM IIRC. The PDP ran RT-11 V4. Other than that, networks were built using 1200 baud modems on serial lines. No DMF32 nor DZ11 in '79. How did one connect all those VT52's and LA36's, via a DL11? I thought DZ11s were around back then. But if not, the DH11 sure was, 16 lines, DMA output. But that's for terminals up to 9600 baud. For networking, you'd use a DMC-11 unless your OS supported the cheaper devices and money was that tight -- that one goes back to about 1976 and delivers up to 1 Mb/s depending on model (up to 56 kB/s long haul, given suitable modems). Lots of terminals with single line interfaces would be really ugly. But I do remember our college main timesharing system, in 1973, a PDP-11/20 with 28 kW of memory, RSTS V4A, and 16 terminals on 16 separate KL11 or DL11 interfaces. Oh yes, and a mean time between crashes of about 1 day. paul