> From: Glen Slick
> For the curious about the eBay market value of the PDP-11/20 today
That one was a once-in-a-lifetime thing, though: not only a KA11 in
absolutely pristine condition, but also an additional BA11 stuffed to the
gills with memory; the most complete set of original documentation I have
_ever_ seen with a computer that old; a complete H960 in perfect condition,
with all the blank panels, the rear door, etc; trays and trays of original
paper tape software, etc, etc.
When you consider that that PDP-11/70 that went a while back for $10K - and
-11/70's are a lot more common that -11/20's - I think this one was easily
worth what it went for.
I'm quite serious - I doubt we'll ever see another -11/20 in this good a
shape, and this complete, for sale, at least, not in my remaining lifetime.
Noel
Think it was add on box that went for the $$$$$! ---Ed#
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------
From: Glen Slick <glen.slick at gmail.com>
Date: 7/24/16 20:08 (GMT-07:00)
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Subject: Re: Straight 8 up on Ebay just now
>
> Straight PDP-8
> http://www.ebay.com/itm/152171436497
>
> PDP-11/20
> http://www.ebay.com/itm/201624309371
For the curious about the eBay market value of the PDP-11/20 today, it
just sold for $5,655.55
After successfully repairing the G231 module of the MM11-L set I continued
with the next one. This one was not able to access addresses ending 0100
(binary). Luckily it was not the transistors arrays that were bad but the
selector chip. A Signetics N8251 chip.
I found a source on ebay at $4.95 each plus $13 shipping. A little bit to
much for my taste (although I could make an offer)
Anyone know of a cheaper source? I could use five or ten maybe.
/Mattis
I've finally started digging through all my stuff in storage, at least
in a small way. Two (or three) things I've found so far might be of
interest here. (There will likely be more eventually, but it's
anybody's guess when I'll find the round tuits to do more digging.)
- One DEC 54-17507. Google makes me think this is the Qbus backplane
from a BA123. It appears to be in good shape; while I am not set up
to test it, it looks pretty much "too simple to break". It consists
of the PCB, the Qbus connectors on one side, two 18-pin power
connectors and one ten-pin connector with blue plastic shroud on the
other side, and a piece of heavy sheet steel all this is bolted to.
(And the bolts, of course. :-) Oh, all four resistor packs are
installed.
- Two Sun type-4 keyboards. (Whether the list is two or three things
depends on whether you count these as one thing or two.) They are
somewhat age-yellowed, and one of them has some stain spots. All
the keys appear to work mechanically. I have a machine I can test
these with, but I will have to first dig out a suitable cable;
whether they are available now or later depends on whether you want
to wait for me to find a cable to test them.
These are in Ottawa (Canada's national capital, for those who don't
know the name or who want disambiguation) and are anyone's for the
claiming. In theory I can ship, but in practice I find I totally suck
at getting stuff shipped (I have two things pending shipping right now,
pending for long times), so you are much more likely to get something
soon if you can pick it up or give me a local(ish) place I can drop it
off, and if someone wants something shipped and someone else is
prepared to pick it up, I'm taking the easy-for-me option.
/~\ The ASCII Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents-montreal.org
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
I was digging around in storage and found a 965 board that is missing
its eproms. Does anyone have one handy that they could dump the proms from?
It's kind of unusual in that it uses a 65816 cpu. Seems to be a midway
design between the earlier 6502's and the later 68000's.
> Guess I should document all this in the Computer History Wiki
OK, done:
http://gunkies.org/wiki/PDP-11/24
> those prints (KT-24, and -11/24 backplane) would still be useful.
Big thanks for Al for putting the KT24 prints up - very good to have them.
> I guess it will require getting ahold of a backplane, and seeing what I
> can find out with an ohm-meter.
It looks like I'll still have to do this at some point, to confirm my
theories about how the two busses are wired on the backplane (separation of
UB and EUB address lines, and cross-connection of the data lines, for the
EUB/SPC slots), since we still don't have any backplane info.
Another mystery: The "PDP-11 UNIBUS Processor Handbook" (1985) says (pg. 4-10)
that in the 5.25" box, "only one MS11-P memory module can be
configured". Anyone know the cause/source of that restriction?
I don't think it can be the backplane; i) AFAIK, the 5.25" and 10.5" (for
which no limitation is stated) boxes use the same backplane, and ii) the 5.25"
box can take more of the smaller MS11-L cards (albeit, again, limited - to
three). So I don't think it can be 'the backplane doesn't carry all 22 address
lines to all EUB slots' (although I will check); and the CPU does drive all
22.
My next thought was that it's some power supply current issue, but on
checking, that board only uses +5V, and there's nothing about limiting the
number of ordinary boards when an MS11-P is in use. (I have to check the power
supply specs, and compare with the board power consumption specs, to make
completely positive there's no issue there.)
So I can't come up with any technical rationale for that limit? Am I missing
something? Or is it just DEC marketing, trying to limit how powerful the
machine can be?
Noel
I'm on the hunt for diskette images of DEC VAXmate software. From a
post to comp.sys.dec there appears to be at least the following
diskettes, but possibly more:
VAXmate MS-DOS version 3.10 for VAXmate Oper Environ V1.1
VAXMATE S/A INSTALL V1.1
VT240 EMULATOR UPDATE For VAXmate Oper Environ V1.1
VAXMATE INFO. SYSTEM V1.1 FOR VAXMATE OPER ENVIRON V1.1
VAXMATE MS-WINDOWS V1.03 (three disks)
If anyone has the diskettes or can point me somewhere to look, it
would be appreciated.
thanks.
Other notes:
If anyone is desperate to own a VAXmate I can provide contact details
of someone who has a few.
Here is my VAXmate running a generic MS-DOS 4.0, the screen is very
dim, and a few other pictures (as it arrived, so before any cleaning -
quote dusty inside):
https://goo.gl/photos/cQkbekoLiWBCZoad9
Hi,
I have got a 9845B which has a defective power supply unit - obviously a very common problem.
After replacing the cracking epoxy capacitors I found that the mains transformer seems to have a broken input winding.
Maybe someone tried to run it at 220V using the 110V input selector switch.
What I am now looking for is a defective PSU with a good transformer, resp. just the transformer which may also have been used in other HP devices..
The transformer is located on the PSU mother board between the two large capacitors.
It has the part number "9100-4037" and the date code "8-81" printed on it. It has two input windings and three output windings. Thus the output is a bit different (one additional winding compared to Tony Duells schematics).
Maybe someone can help?
Martin
