🚀 go-pugleaf

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