[comp.sys.dec] Digital PDT-11 ... what is it?

blee@plains.NoDak.edu (Blaine Lee) (06/22/91)

First of all, thanks to everyone who helped out before on the sharing of
binarys on DEC's.

I was hoping someone has heard of a little box digital made about eight
years ago, the PDT-11.  I received one from a GM dealer that used it for
comunications with GM's main computers.  It is 18 inches high, 30 inches
deep, and about 18 inches wide, it has two eight inch drives on front, and
I believe I found one or two 8085's in it.  

Is this a common machine, or a special item made for GM?  Does anyone have
software for it?  I do have the software that came with it, but all that is
just some very special stuff for GM.

(yes GM means General Motors.)

Blaine Lee
blee @ plains.nodak.edu

chad@oscar.cs.byu.edu (Chad) (06/22/91)

--

We used to have a PDT-11/150 at home.  It has an LSI-11 processor and
runs RT11.

(My dad works at DEC and employees were able to purchase them for $1000
including terminal (VT62) and 300bps paper terminal.  Of course, we got
software for free as employees.)
*************************************************************
Chad Leigh 
Brigham Young University / on leave from DEC
chad@yvax.byu.edu /  chad@norge.enet.dec.com
*************************************************************

martin@adpplz.UUCP (Martin Golding) (06/25/91)

In <10923@plains.NoDak.edu> blee@plains.NoDak.edu (Blaine Lee) writes:

>First of all, thanks to everyone who helped out before on the sharing of
>binarys on DEC's.

>I was hoping someone has heard of a little box digital made about eight
>years ago, the PDT-11.

About 10, I think. The computer people found out what the terminal people
were building, and made them stop. They offered us real PDP 11's as
replacements at _4 times_ the cost, which is how we got started building
computers.  In 1981 I started working on the software for the second
generation replacement for the PDT. Of course, being the thrifty types we are,
we were reconditioning and reselling them up to a couple years ago. They got
to be _so old_ that one prom (for unique serial number) was only available
from military suppliers at $50 a pop. 


>I received one from a GM dealer that used it for comunications with GM's
>main computers. 
>I believe I found one or two 8085's in it.

Yep, more or less. See below.

>Is this a common machine, or a special item made for GM? 

Nope. See more boring discussion below.

>Does anyone have software for it?  

Your first problem will be finding anybody who can supply useful software on
8 inch floppies. Or, some nice person with dial up access and Kermit or
the equivalent.


>I do have the software that came with it, but all that is
>just some very special stuff for GM.

Not, exactly.

The box you have was almost certainly distributed and software provided
by ADP Dealer Services; we used to have tens of thousands of the damn
things lying around. It sold with the RT11 OS, a special multi-user
addon, and communications code to call various manufacturers (not just
GM) using various obsolete communications equipment (202s), for ordering
and inquiry. (Hey, it replaced a dual cassette Astronautics 301e, which
replaced a tty ksr with paper tape reader/puch, ok? At the time, it was
a good idea.)


The PDT-11 (stands for Programmable Data Terminal) was a cute box with
two 8 inch floppies, an LSI-11 (which isn't really a PDP-11) and a Q bus
that isn't there:

The LSI-11 was _really_ an 8 bit microcodable processor (rumors of P-code
interpreters abound) coded to run the PDP 11 instruction set. The 8085
(if you say so, I haven't seen one lately) pretends to be portions of the
bus, at least the DLV11 (terminal) interfaces. I'm not sure if it runs a
theoretical disk controller as well. (The 11 starts a memory cycle, the
80xx gets an interrupt, figures out what the question is, does that, and 
completes the cycle. Up to a few _hundred_ microseconds for a read or
write, but the software is compatible.)

The PDT-11 runs the RT11 operating system, and any RT11 programs that
are functional in the disk and memory you've got, which isn't much.
(Some models were 32k, others up to _wow_ 56). At least the KED editor
ought to be available, you may never have to vi again! If you can figure
out how to move it onto your machine, I _may_ be able to email you hex
copies of some of the tools. I don't know if they run on non-virtual
RT11, though. We've been on TSX for years.


More war stories on request- don't ask!

Martin Golding    | sync, sync, sync, sank ... sunk:
Dod #0236         |  He who steals my code steals trash.
A poor old decrepit Pick programmer. Sympathize at:
{mcspdx,pdxgate}!adpplz!martin or martin@adpplz.uucp

bill@pyrite.nj.pyramid.com (Bill Pechter) (06/25/91)

In article <10923@plains.NoDak.edu> blee@plains.NoDak.edu (Blaine Lee) writes:
>
>I was hoping someone has heard of a little box digital made about eight
>years ago, the PDT-11.  I received one from a GM dealer that used it for
>comunications with GM's main computers.  It is 18 inches high, 30 inches
>deep, and about 18 inches wide, it has two eight inch drives on front, and
>I believe I found one or two 8085's in it.  
>
>Is this a common machine, or a special item made for GM?  Does anyone have
>software for it?  I do have the software that came with it, but all that is
>just some very special stuff for GM.
>
>(yes GM means General Motors.)
>


The PDT11 was a series of machines, all based on the LSI 11 chipset 
(11/03).   There was the PDT11/150 (that you have), the PDT11/130 with 
two DECtape TU58's, the PDT11/110 with no storage devices.  

The latter two were built into VT100 cases with the VT as the console device.

The PDT was built for a number of uses, terminal concentrator, workstation...

I heard the Post Office was looking for a machine like them to automate
the Postal Service - but that they didn't go with the DEC box.
The PDT was used by many car dealers.

It does run DEC RT11 software (including the current V5...)

DEC had a ton of them in a warehouse and sold them to employees (encluding
me)for PC use.  They're a lot of fun.  RT11 is a great O/S and PDT's can do
more in 64k of memory than MS-DOS can in 640.

Hope this helps.

Bill
-- 
Bill Pechter                       | "The postmaster always pings twice."
Pyramid Technology                 | bill@pyrite.nj.pyramid.com
10 Woodbridge Center Drive         | rutgers!pyrnj!pyrite!bill
Woodbridge, NJ 07095 (908)602-6308 | pyramid!pyrnj!pyrite!bill

bill@pyrite.nj.pyramid.com (Bill Pechter) (06/26/91)

In article <834@adpplz.UUCP> martin@adpplz.UUCP (Martin Golding) writes:

>I don't know if they run on non-virtual
>RT11, though. We've been on TSX for years.
>More war stories on request- don't ask!


Please, I love the PDT and figured that if DEC would've sold them as inexpensive
PC's all PC's would be multi-tasking machines instead of the &*^%$#
TSR-laden stuff we have now.

Blame Ken Olsen for short-sightedness.  I do.

Bill
-- 
Bill Pechter                       | "The postmaster always pings twice."
Pyramid Technology                 | bill@pyrite.nj.pyramid.com
10 Woodbridge Center Drive         | rutgers!pyrnj!pyrite!bill
Woodbridge, NJ 07095 (908)602-6308 | pyramid!pyrnj!pyrite!bill