24 Dec
2015
24 Dec
'15
10:59 a.m.
Date: Tue, 22 Dec 2015 20:56:51 -0600
From: Jay Jaeger <cube1 at charter.net
Subject: Re: PDP-12 Restoration at the RICM
Message-ID: <567A0D73.2010304 at charter.net
Content-Type: text/plain; charset=utf-8
I have an image of MAINDEC-12-D8CD-PB, and a listing as well
(MDEC-12-D8CD-L in my inventory). Let me know if you need them as well
as the drawings (see below). It is in an archive folder with a bunch of
other interesting PDP-12/PDP-8 stuff.
I wrote a program to export a BIN formatted file from a LINCtape image so
we were able to make a BIN image of MAINDEC-12-D8CD. This runs OK, where
the D8CC does not.
Can you give me a pointer to the SerialDisk info? Sounds interesting.
24 Dec
24 Dec
2:22 p.m.
On 12/24/2015 9:59 AM, Michael Thompson wrote:
The prints that came with this PDP-12 are here:
http://bitsavers.trailing-edge.com/pdf/dec/pdp12/maintenance/DEC-12-HR2B-D_…
??? That document is not prints. I suspect you meant:
http://bitsavers.trailing-edge.com/pdf/dec/pdp12/maintenance/DEC-12-HR1B-D_…
Which is the same revision as mine. (I see that the 1969 edition is
also there, but under the name PDP12-MaintVol3_SchemsMar69.pdf).
We have been able to fix all types of broken flip-chips. Sourcing the
components is sometimes a challenge. The Germanium transistors for the TU20
on the PDP-9 were hard to find.
I remember replacing a germanium (at least I think it was) transistor on
an SMS card with an ordinary silicon transistor in a 7094-II floating
point unit back around 1974. Luckily, that worked fine, though for a
museum I imagine one would prefer to use the "real thing". ;)
We found that the maintenance prints that came with the system do not
include ECO EM12-0055.
Does anyone have a set of KW12 prints that include ECO EM12-0055?
Jay, we are interested in anything PDP-12 related that we don't have.
Eventually I expect I will, over the next few years, scan in everything
that is not already on bitsavers, but it looks like your current needs
have been met.
The PDP-12 is described here:
http://www.ricomputermuseum.org/Home/equipment/dec-pdp-12
Details on the PDP-12 restoration process are here:
http://www.ricomputermuseum.org/Home/equipment/dec-pdp-12/dec-pdp-12-restor…
JRJ
4:58 p.m.
On 12/24/2015 01:22 PM, Jay Jaeger wrote:
On 12/24/2015 9:59 AM, Michael Thompson wrote:
Yes, I overhauled an old HP digital frequency synthesizer
that was all built out of PNP Germanium transistors (no
ICs.) I substituted the first one with a VHF Silicon
transistor and did some tests on the bias, etc. and was
pleased to find it was a total drop-in replacement. I
replaced over 10 of them in that unit, and they all worked
flawlessly.
I can imagine some difficult circuits where you couldn't get
away with this, maybe a magnetic read amp or a timing
circuit or something, but I think in most cases a Silicon
transistor will work well.
Jon
We have been able to fix all types of broken
flip-chips. Sourcing the
components is sometimes a challenge. The Germanium transistors for the TU20
on the PDP-9 were hard to find.
I remember replacing a germanium (at least I think it was) transistor on
an SMS card with an ordinary silicon transistor in a 7094-II floating
point unit back around 1974. Luckily, that worked fine, though for a
museum I imagine one would prefer to use the "real thing". ;)
5:04 p.m.
On 2015-Dec-24, at 1:58 PM, Jon Elson wrote:
On 12/24/2015 01:22 PM, Jay Jaeger wrote:
Similarly, I've replaced Ge with common Si in repairs of 60s-era discrete-component
equipment and had no problems.
On 12/24/2015 9:59 AM, Michael Thompson wrote:
Yes, I overhauled an old HP digital frequency synthesizer that was all built out
of PNP Germanium transistors (no ICs.) I substituted the first one with a VHF Silicon
transistor and did some tests on the bias, etc. and was pleased to find it was a total
drop-in replacement. I replaced over 10 of them in that unit, and they all worked
flawlessly.
I can imagine some difficult circuits where you couldn't get away with this, maybe a
magnetic read amp or a timing circuit or something, but I think in most cases a Silicon
transistor will work well. We have been able to fix all types of broken
flip-chips. Sourcing the
components is sometimes a challenge. The Germanium transistors for the TU20
on the PDP-9 were hard to find.
I remember replacing a germanium (at least I think it was) transistor on
an SMS card with an ordinary silicon transistor in a 7094-II floating
point unit back around 1974. Luckily, that worked fine, though for a
museum I imagine one would prefer to use the "real thing". ;)
5:45 p.m.
On Thu, Dec 24, 2015 at 9:59 AM, Michael Thompson <
michael.99.thompson at gmail.com> wrote:
Kyle's SerialDisk is here: https://github.com/drovak/os8diskserver
I just pushed some changes earlier. Hopefully I didn't break too many
things! :) The system handler now has support for FRTS. Still need to add
support for older machines (I intend to add separate handlers but still
maintain compatibility with the same server).
Congrats on the great progress, Michael!
Kyle
3167
days inactive
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days old
4 comments
5 participants
participants (5)
-
cube1＠charter.net -
elson＠pico-systems.com -
hilpert＠cs.ubc.ca -
kylevowen＠gmail.com -
michael.99.thompson＠gmail.com