Subject: PDP-8 Collectors

From: [email-masked] (Charles B. Owen)
Date: Thu, 5 Nov 1992 16:23:09 GMT

I was very interested to notice this new newsgroup.  I have long been
interested in obtaining a small PDP-8 system as a collector item,
to restore and get operational.  I think lots of the machines are still
floating around (???)

Questions:

Is anyone else doing this, as just a hobby (not maintaining one for
business use)?

How available is software that I would not have to pay DEC for?  Much PD
available?  For obsolete hardware, it would almost make sense for DEC to
give the stuff away.  

Any problem maintaining these systems?  I am very good at electronics,
so I can handle anything I can get parts for.  But, are there many
custom parts that are difficult to obtain?  (particularly mechanical
parts)  DEC still support?  (Reasonably)  

Any idea what used systems are costing?  I an talking about the real
PDP-8's, not the Rainbows.

Thanks for any comments.
Charles B. Owen

-- 
| Charles B. Owen                            Internet: [email-masked] |
| Western Illinois University                            Phone: 309-837-4292 |
| 1002 E. Murray                                                             |
| Macomb, IL  61455                                                          |

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From: [email-masked] (Douglas W. Jones,201H MLH,3193350740,3193382879)
Date: Thu, 5 Nov 1992 19:54:26 GMT

>From article <[email-masked]>,
by [email-masked] (Charles B. Owen):
> I think lots of the machines are still floating around (???)
	Yes they are.  Over the summer, I picked up three Omnibus machines
	(model E, F and A) at U of Iowa surplus, and I know where there are
	a number of model I and L machines on campus, yet to be sent to
	surplus.  I suspect that most big research universities are similar,
	with various machines mothballed or in storage closets in various
	places on campus.  Look in the back storerooms of chemistry,
	engineering, or psychology labs for such things.
> Is anyone else doing this, as just a hobby (not maintaining one for
	I have a model E and a model F in my study at home, neither works
	yet, but I ought to be able to get one up fairly soon (given the
	time to track down some bugs in the front panel).  If I had a spare
	RX8E board, I'd be able to build two complete useful systems, since
	I have two RX01 dual diskette drives.

	At work, I've talked our department into providing a home for a
	1966 vintage PDP-8, and I have a small group of students starting
	the job of figuring out whether it is safe to plug it in and try
	turning it on (such wonderful questions as: are all the flip-chip
	modules plugged into the right slots, and what cables go where?)

	There are also very likely to be many industrial users of PDP-8
	based systems.  Just last month, I was talking to a man from an
	Alcoa plant, and he said that they were still using NC machines
	that were real antiques.  I'd lay even odds on an antique NC
	machine being PDP-8 based!
> available?
	There's a young but growing PD repository of PDP-8 software at
	ftp.telebit.com.  I'm not clear on whether I have the right to
	distribute the ancient DEC source code I have, but I'll be finding
	out.

> For obsolete hardware, it would almost make sense for DEC to
> give the stuff away.
	Yes.  So far, DEC has been quite nice about granting permission
	to reprint their documentation, and I imagine they'll let us do
	the same to their ancient software, but I have not confirmed
	this.  Remember that DEC only discontinued the PDP-8 product line
	in 1990 with the demise of the DECmate III+, so some PDP-8
	software may still be considered to have current market value,
	and DEC probably still has a number of customers with service
	contracts and other money making relationships who are running
	DECmates and end-of-the-run Omnibus machines.
> parts)  DEC still support?  (Reasonably)
	Everything can still be found commercially, much of it on the
	reconditioned second-hand market.  Individual boards for the
	OMNIBUS models of the PDP-8 sell for about $75, on the price lists
	I've seen.

	If you get a classic or straight -8, parts are no problem, since
	everything is discrete component, and plain transistors and diodes
	will never go out of style.  If you get an OMNIBUS machine, there
	are custom SSI and MSI chips used that are out of production.  If
	you ever need to replace such a chip, you'll have to hunt down
	one of a small stock of spares or cannibalize a chip from a
	different board.  I have collected every OMNIBUS board I could get
	my hands on for this purpose, including a number of real junkers
	that were hand kluged I/O interfaces for one-of-a-kind devices.
> PDP-8's, not the Rainbows.
	I bought a PDP-8/E, and 8/F and an 8/A plus two RX01 units for a
	total of $25.  I spent $35 for one relay rack, and got the other
	free.  Of course, when you buy surplus, you never know whether or
	not it will work, and the good prices only happen when there's
	nobody else bidding on the stuff.

				Doug Jones
				[email-masked]

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From: [email-masked] (Johnny Billquist)
Date: Thu, 5 Nov 1992 20:57:34 GMT

>to restore and get operational.  I think lots of the machines are still

Yup, I'd definitely say so.

>Is anyone else doing this, as just a hobby (not maintaining one for

I know of quite a few who maintain pdp8 systems just for the fun of it.
I'm one of them. I have actually scrounged together 7 pdp8 systems.

>available?  For obsolete hardware, it would almost make sense for DEC to

I'd say you could get every piece of software for the pdp8 without
paying anything. DEC has released much to DECUS, and I doubt they
would try to sell any of it today.

>parts)  DEC still support?  (Reasonably)  

I'm not that very bright on electronics, but I'm not having too much
trouble keeping systems running. Just get the drawings for the machine
and everything will be quite easy. DEC also still has some of the hardware
in stock, if you just ask the right person.

>PDP-8's, not the Rainbows.

Most of these systems goes for free nowadays. Maybe a few bucks, but
not much.

Rainbow is not a pdp8, by the way. I suspect you are thinking of the
DECmate I, II and III.

>Charles B. Owen

You're welcome.
-- 
Johnny Billquist                  || "I'm on a bus
CS student at Uppsala University  ||  on a psychedelic trip
email: [email-masked]       ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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From: [email-masked] (Seth L. Blumberg)
Date: Fri, 6 Nov 1992 01:30:12 GMT

>machine being PDP-8 based!

Oh, yes indeedy, there are many, many industrial PDP-8 setups out there.  A
guy I used to know--field service rep for a measuring-equipment company--said
that his main job is maintaining 8/L and 8/I (and some 8/E or /F) setups
installed back in the late '60s, early '70s.  Apparently, it's mostly the
specialized OEM hardware that needs fixing--the 8's just keep on rolling.
Many plants that use his company's stuff also use 8-based NC rigs.  Kind of
awe-inspiring, when you think about it.

>				[email-masked]

	Seth "the Lesser"

Seth L. Blumberg          \ Sturgeon's Law: 90% of everything is crap.
[email-masked] (play)   \  Blumberg's Corollary: And the rest ain't so
[email-masked] (work) \        hot, either.
   > No one I know shares my opinions, least of all Columbia University. <

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From: [email-masked] (Paul Lafollette)
Date: 6 Nov 92 02:03:46 GMT

Wow. Reading this makes me miss "my" LINC-8.  Wish I could find
one and had room and time to set it up.  Incidentally, up until
last year I was still teaching PDP-8 assembly language in one
of our courses here. (Not my decision, but it was fun anyhow.)
I think I still have a couple copies of the little brown book
that DEC gave out on reserve in our library :)

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From: [email-masked] (Robert Armstrong)
Date: Fri, 6 Nov 1992 17:36:18 GMT

>Is anyone else doing this, as just a hobby (not maintaining one for

  I have an 8/A that's currently in storage, although I used to
run it all the time before I ran out of room to keep it!  It has
two RK05s (an F and a J), RX02, TU56, 32K MOS (I also have a 16K
core board, but it takes up too much room in the backplane), and
a real VT52 for a console.

  I've also owned a few DECmates and one VT78, but I don't have
any at the moment.

  I also built a system once based on the IM6100 and 6102.  It had
8K RAM and a cassette tape (that's an _audio_ cassette, Kansas City
format!) interface.  I managed to get FOCAL running on it.

>available?  For obsolete hardware, it would almost make sense for DEC to

  There's an archive of some PDP-8 software at telebit.com.  Also,
OS/278 is available, with or without sources, from DECUS.  A few
other PDP-8 software packages are still available from DECUS.

  Other than that, DEC isn't giving any software away.  They've given
permission to reproduce hardware manuals that they no longer sell,
but as far as I know DEC's never given permission to distribute old
PDP-8 software.  I'm sure there's no value in holding on to it -
probably there's just nobody willing stick their neck out and say
"It's free!".

>parts)  DEC still support?  (Reasonably) 

  The later machines, 8/I and after, use standard TTL parts.  The 8/A
had a few LSI chips, like UARTs, in it.  I've successfully replaced
chips on my RK8E controller and LP8E.  I still see PDP-8 components for
sale by some of the used DEC equipment resalers, but not nearly as much
as there was 10 years ago.  Used DECmates are still relatively easy
to buy from these places.

  I've no idea if DEC still sells replacement parts.  They'd probably
be much too expensive to be useful even if they did.

  Good luck.

Bob Armstrong
[email-masked]

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From: [email-masked] (Randell Jesup)
Date: 6 Nov 92 20:24:46 GMT

>	modules plugged into the right slots, and what cables go where?)

	The RPI-ACM once (early-80's) had a PDP-8 (no /anything), ALL flip-
chips, with adjustable power supply for preventive maintenance, and an entire
second cabinet of flip-chips for running X-ray crystallography experiments.
(It included a pulse-amplifier hooked up to a speaker for playing music...)

	I designed (but never built) a DMA printer driver using flip-chips
to run a 700 LPM Burroughs line-printer we also happened to have.  (That
printer was eventually responsible for sending me to the hospital, when we
had a "printer-bash" during GM week...)

	I also use an 8/e with dectape in high-school.  I still have about 10
tapes, mostly set up using Educomp OS/8 and EduBasic.  I also have 3 trays of
paper-tape software, including Focal, a couple of basics, fortran (I think),
and a bunch of other things, including a chess program.

	The RPI PDP-8 was lent to the secretary for a halloween thing at his
fraternity (he wasn't much into real programming), and his fraternity burnt
down before he returned it.  argh....  I wanted that machine...

	I would _love_ to get my hands on an 8/e with tape drives.  Even
an 8/anything with paper tape would be better than nothing.

-- 
To be or not to be = 0xff
-
Randell Jesup, Jack-of-quite-a-few-trades, Commodore Engineering.
{uunet|rutgers}!cbmvax!jesup, [email-masked]  BIX: rjesup  
Disclaimer: Nothing I say is anything other than my personal opinion.