[rescue] PDP11 adventures

Patrick Finnegan pat at computer-refuge.org
Mon Dec 4 20:30:17 CST 2006

On Monday 04 December 2006 13:39, Curtis H. Wilbar Jr. wrote:
> OK... so I'm now the new (proud :-) ) owner of a PDP-11/83.


> I'm new to the PDP11s, so, I'm not even powering this thing up until I
> get educated.
> This is the config
> In the system (183QA-D2) box:
> M8637-EF (2MB ECC RAM)
> M8190-AE (11/83 CPU, FPJ11-AA)
> X, M9047 (nothing, grant continuity)

BTW, the empty slot probably shouldn't be empty.  You should either fill 
it with an M9047 grant card, or remove the grant card next to it, and 
move all the rest of the cards in the backplane "up" by one row.

> Now... for questions:
> is FPJ11-AA floating point, and does that mean my cpu card has that
> built in ?

All 11/83's have built in floating point.  The FPJ11 is a floating-point 
accerator, which sits in a socket on the 11/83 cpu board.

> What is the max ram ?  i.e. how many more M8637-EF (or higher
> capacity) cards can be aquired and put in ?

4MB == 2Mw. (Really only 2044kw, since 4kw is reserved for the I/O page.)

> Anyone have a TSV05 tape drive local to Sharon, MA ?  Or, anyone in
> need of a TSV05 controller ?

I don't. :)

> What is DDCMP control ROM ? that my M8053-MA has ?

DDMCP relates to decnet; I think the rom lets you boot via DECnet over 
the serial port on the card.

> What is a DRV11-WA general purpose 18/22 bit parallel interface ?  Can
> this be used for a parallel printer ???

No.  It's a bi-directional 16-bit (2 ports per card I think) card.  It 
works like a serial port card, only transferring data in parallel 
instead. :)  They're typically used to connect other equipment (like lab 
equipment) up to the system.

> As I'd like to have larger storage on it at some point, I'd like to
> locate a SCSI
> (or possibly ESDI ?) controller.  What should I be looking for, anyone
> have one ?

I've got a couple.  Depending on the model, they seem to sell for 

> I'm looking at running BSD (2.11 ?) and other PDP11 OSes...
> suggestions ?

As someone else mentioned, http://simh.trailing-edge.com

> There doesn't seem to be a reason to the layout of the grant
> continuity cards.
> Shouldn't there be one in the left side of the 3rd slot from the top
> in the 183QA-D2
> (system unit) ?


> What is the minimum card config to start testing with ?

The memory card and the CPU board is all that is required.

> Any pointers on how the RQDX3 and RQDXE cards should wire up ?  The
> RQDXE in the system unit has a wide ribbon cable running to the front
> (which I presume breaks into the control/data wiring for an MFM drive
> there).. but the RQDX3 doesn't connect to the RQDXE ..

You probably don't really need the RQDXE.  BA23 cabinets have the 
equivalent of an RQDXE built-in to them.

Purdue University ITAP/RCAC       --- http://www.rcac.purdue.edu/
The Computer Refuge               --- http://computer-refuge.org

More information about the rescue mailing list