From mboxrd@z Thu Jan 1 00:00:00 1970 From: pete@dunnington.plus.com (Pete Turnbull) Date: Mon, 25 Jan 2016 16:18:06 +0000 Subject: [TUHS] PDP-11 questions In-Reply-To: References: <1453675247.12547.for-standards-violators@oclsc.org> Message-ID: <56A64ABE.6070709@dunnington.plus.com> On 25/01/2016 11:29, Tony Finch wrote: > Norman Wilson wrote: >> >> It worked both ways, of course. I too suspect that a >> majority (though I'm not so sure about `vast') of PDP-11s >> never ran UNIX. > > A random vaguely off-topic example: in Cambridge a PDP-11 was used as a > terminal multiplexor for the IBM mainframe. The University of Leeds did something similar - an 11/34 with a lot of Emulex serial lines and an RX02 to boot from, was connected to their Amdahl. I remember the RX02 particularly because when we decommissioned it and took out the floppies, both had completely transparent rings on or near track zero, so it obviously had been left running and not rebooted in quite some time. In the same machine room there were two third-party cabinets with KDJ11A CPUs, more serial lines and IBM channel interfaces. They also had at least one DX11. The University of Edinburgh used several small PDP-11/23s in BA11-N boxes as terminal/network concentrators for EMAS. I can't remember how they worked but I remember they had one sync serial interface and a bunch of DLV11-Js. -- Pete