Demonstrations at the PDP-11 SIG meeting

November 30, 2000 in Koningshof, Veldhoven


The Ersatz-11 PDP-11 software emulator running on a standard DOS Pentium PC was demonstrated by Peter Vergeer of Vergeer Software BV. It drove PDP-11 SCSI periphals via a standard ASPI SCSI controller. It also could use real QBUS cards in the emulator. The PDP11 cabinet on the right does not hold a processor but only i-o cards, it is connected via a special card to the pc so the emulator can see and use the qbus cards.


To celebrate the 30th anniversary of the PDP-11, Ed Wanderer brought this original PDP-11/35 with RL02 removable drive. The little Sun box on top was a nice gimmick, it spoke aloud everything that appeared on the terminal.


The 11/35 really is an old blinkenlights computer!


The Osprey PDP-11 hardware emulator was also shown. It is available in a special cabinet that has the dimensions of a BA-23 cabinet. The cabinet has the PC with an Osprey card at the side, and at the back space for real qbus cards that can be used by the emulator.


The Osprey card itself. The software that goes with it runs under Windows NT. The software only communicates with the PC periphals, the card is doing all the real work.


The back of the cabinet, with the qbus card cage (underneath the ventilation holes). Nativ computers Ltd was the Compaq partner that installed Osprey systems.

Of course much more subjects were talked about, but I have no pictures of these talks. There was a talk by Arie de Groot of Software Resources International about the Charon PDP-11 software emulator that runs under NT, Linux, OpenVMS or True64. There also is a Charon-VAX emulator. Theo Mudde of Mudde Autoproc presented a lot of practical implementations of Charon, replacing old hardware with new PC-based equipment that could communicate with the emulator. Charon can also use the special card to communicate with real qbus hardware.

There was a talk about a real-world implementation of E11 in a steel factory by Kris van Leeuwe of SIDMAR NV. Some small snags were described, but the emulator worked flawlesly when they were resolved.

Programming guru Dave Carroll of Mentec was there to talk about the future of PDP-11 operating systems. It was funny to notice that the only real problems in the operating systems, of which there were few, seemed to be caused by very fast hardware (or very fast emulators) and very large disks. PDP-11 software is so very boring, because it just always works :)

It was the first time PDP-11 hobbyists and collectors like myself were present at this SIG meeting. It was fun to see what the PDP's are used for before they end up with us (critical things like real time process control, telecommunications, inventory control, driving test- and manufacturing equipment, tasks where the computer just has to always work and work reliably) and that there were things that we hobbyists knew but the pro's didn't, like that you can use Teledisk to copy hard to copy PDP-11 disks with a PC, and create images of those disks that can be easily emailed, or that there is a special program from RT-11 guru Megan Gentry to let PDP-11's quickly transfer files via Ethernet, or the existance of the Classic Computer mailing list which is a very valuable source of information about old hardware, a real community of people preserving old hardware.

Lees meer over de PDP-11 SIG op de DECUS Holland web site (in Dutch mostly)

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