Building a PDP-11 for the first time

From: J.C. Wren <jcwren_at_jcwren.com>
Date: Sun Dec 14 10:40:23 2003

On Sunday 14 December 2003 10:36 am, emanuel stiebler wrote:
> J.C. Wren wrote:
> > Supposing you're one of those people that have always wanted a
> > PDP-11/74, but know next to nothing about them.
>
> If you know nothing about them, why do you want one ?
> ;-)

        Over the years, the PDP-11 family has come to represent something I've missed
in computing history. It's almost reached the point where "well, I'm a
programmer, but not a *real* programmer, because I've never driven a PDP-11".
Below is a little tale, that will bore most people to death, I'm sure.

        It is for the same reason that I WILL own a Ferrari 308, at some point.
While it's not an F-40, and not a particularly fast car, it represents a
design pinnacle of sorts. Yea, they're a little uncomfortable to get in and
out of, and maintainence ain't always cheap, but the lines, the history... No
where is there a more beautiful car. The PDP-11 has become the 308 of
computing for me.

        I still don't know exactly which 308 I want. Carbs are a nuisance on those
things, but they make a little more power, and sound a little more like a
Ferrari should. FI is more reliable, but Ferrari FI has this weird idea that
when you cold start them, they should immediately jump to a 2K fast idle.
Hard top or soft top? Advantages, disadvantages. When I actually have cash
in hand, I'll decide. Except for the color. It WILL be red.

        When I got into computing, the exact year of which I cannot remember (and
probably don't want to), the Sol-20 was fairly recently available, and
Apples ]['s hadn't come out yet. I had a little minor experience on an IBM
mainframe, and something in the AT&T 3B family though dialup, courtesy of a
friend of mine that worked at AT&T.

        About 3 months after the introduction to the 3B, a computer store in Atlanta
opened literally up the street from me, called "The Byte Shop". I was there
the day they opened, and they had to just about physically throw me out that
night.

        I had no connections to people who had access to PDPs, P&E's, or other
machines in that class. A fellow who turned into a good friend of mine at
the Byte Shop got me a lot of time on IBM 360s and 370s at Cotton State
Insurance, where he was a sysadmin. I learned Fortran there, and some long
forgotten things about VM and CICS.

        Like many people, where the path split with the introduction of
microcomputers, I took the micro path. I've layed hands on dozens of models
of systems, manyof which I've forgotten. But there were the Poly-88's,
IMSAIs (somewhere, a VDP-80 is looking for a home with me), PT systems (oh
yea, wouldn't mind a 4 drive Helios drive cabinet for my Sol-20), Northstars,
Apples, Sphere Research, just to name a few.

        At Georgia Tech, I spent easily hundreds and probalby thousands of hours in
the terminal cluster, connected to a Cyber 74. Down the hall where Pr1mes,
but I never had the right connection (people wise) to work on those.

        PCs came out, and I dropped the long loved Z80s, 6502s and 6800s to pursue
this newer faster machine. Anyway, etc, etc, etc. Got into embedded
systems, working with 8051s, 6809s, DSPs, RISC processors, all sorts of
stuff.

        I've got two PDP-8 SBCs here, Bob Armstrongs kits. They both run, and you
can do useful work (for certain values of useful :) ), but you can't run any
kind of Unix on them (I have hundreds of hours on a PDP-8 desk model (I can't
recall the suffix. /i? /a?).

        I think the problem was I was too young, back then, and failed to realize
computing was splitting, and I should make a choice. Not having exposure to
the PDP class machines, and Unix in general, didn't help. Can't choose what
you didn't know. I don't think the way I went was wrong, by any means, but I
defaulted into this branch, instead of choosing. And at times, I wish I had
gone the other way. Unix is a better choice than DOS and Windows, and I
could have been more involved at the Linux forefront.

        At this point in time, a PDP-11 is still cheaper than a Ferrari, and I can
buy one piecemeal (unless I luck into someone disposing of one, and I don't
have that kind of luck. I have a different kind of good luck, but it's not a
type that involves people giving me highly desirable equipment). What I *do*
know is that my PDP-11 should have a front panel. But it doesn't have to be
red :)

        --jc
Received on Sun Dec 14 2003 - 10:40:23 GMT