PDP11 adventures

Zane H. Healy healyzh at aracnet.com
Tue Dec 5 10:45:00 CST 2006

At 1:27 AM +1300 12/6/06, Ethan Dicks wrote:
>I don't know either... I've only ever used sleds with a BA23.
>I haven't tried it myself, but it may be possible to fabricate
>something close enough to work with ordinary shop tools and a sheet of
>plexiglass/perspex.  Has anyone on the list ever tried to make DEC
>drive sleds from scratch?

I might be getting it confused with a 3rd party chassis, but I'm 
pretty sure I've seen a metal drive sled, rather than the standard 
DEC Plastic sleds.  At the same time, getting the thickness right is 
what will cause problems I suspect.

>>The SCSI controllers are relatively hard to come by, but the Emulex DQ07
>>(iirc) seems to be one of the most common, and is the one I have.
>Viking and CMD controllers were also common, IIRC.

It has been my experience that the Viking controllers were *very* 
common and rebadged by at least a couple companies.  All of my main 
PDP-11's are using Viking QDT & UDT controllers.

>Unless you have a small quantity of ESDI drives, I'd suggest you be on
>the lookout for a Qbus SCSI controller.  They aren't usually under
>$250 US, but even at that price (if it hasn't gone up recently), the
>ability to use more modern drives is rather nice unless you are more
>interested in a 100% vintage arrangement from before the time of SCSI
>(by the time the 11/83 came around, SCSI drives weren't that rare on
>DEC machines, but the controllers never were inexpensive).

If he looks for a ESDI controller, I'd recommend the Webster WQESD/04 
controller.  Personally it is the one non-SCSI 3rd party controller 
I'd want to run (I did for several years).

>2BSD is a nice choice if you want Unix.  RT-11 was common for smaller
>systems, and RSX-11/M and RSTS were common for larger configurations.
>If you aren't married to Unix, RT-11 is simple enough to pick up
>quickly, especially if you have much MS-DOS or CP/M experience.  I
>went the other way - RT-11 first, then CP/M... made learning to get
>around on a Kaypro a snap.

I've found one of the advantages of SCSI is that it's easy to use 
drive trays to run multiple OS's.  RT-11 is very nice.  Somehow 
either RSX-11M or RSX-11M+ seem a bit more appropriate for the system 
in question.  I'm not sure I'd recommend RSTS/E as a first OS.

BTW, another advantage of SCSI is attaching a CD-ROM drive, which can 
make installing an OS easier.


| Zane H. Healy                    | UNIX Systems Administrator |
| healyzh at aracnet.com (primary)    | OpenVMS Enthusiast         |
| MONK::HEALYZH (DECnet)           | Classic Computer Collector |
|     Empire of the Petal Throne and Traveller Role Playing,    |
|          PDP-10 Emulation and Zane's Computer Museum.         |
|                http://www.aracnet.com/~healyzh/               |

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