On Mar 14 2005, 13:37, Dwight K. Elvey wrote:
> >From: "Pete Turnbull" <pete at dunnington.u-net.com>
> >I still wouldn't use silicon grease, because it creeps over time,
and
> >can cause all sorts of problems, often at some distance from where
it
> >was originally put.
> Yes, it does creep. I just wonder what problems you refer to.
Bad contacts in sockets, accumulation of dust and airborne detritus,
and problems resoldering or modifying boards when they get older. It's
the lighter silicones that cause the problems, though, and if you
can find a modern grease that has a smaller spread of molecular
weights, the problem will be greatly reduced. The difficulty is in
getting rid of the silicones, as they don't wash off, and flow into
holes especially when you heat them up.
I used to do a lot of commercial repairs, especially on 1980s micros,
and I used to hate the ones where people had put gobs of heatsink
compund on socketed chips. The compound contains lots of light
silicones, which used to get into the sockets and cause bad
connections, and then it was a pain to remove the socket and solder in
a new one. Of course, the worst were the ones drenched in "contact
cleaner" and WD40.
--
Pete Peter Turnbull
Network Manager
University of York
On Mar 14 2005, 13:29, Randy McLaughlin wrote:
> You have mis-read the table.
>
> Pin 2 can only change the speed to 300 RPM by lowering pin 2, with
pin 2
> high no matter what the drive runs at 360 RPM.
I have not misread the table. The point is that pin 2 controls the
density, no matter how you set the "LG" jumper, and changing the
density may or may not change the speed, depending on the jumper at
"I".
> The density mode can be high with pin 2 high or low with pin 2 high
> depending on jumpering.
But either way, changing its state changes the density, but not
necessarily the speed.
> The one and only standard the document gives for pin 2 is speed
change.
Read it again. I just did. It does not say that anywhere in the text,
the tables, or diagrams. What it does say or show, in several places,
is that the default setting is "LG" and "I" not fitted, and that that
condition makes pin 2 control the change from normal density to high,
and does not change the speed. It also says in the table that "LG"
determines how pin 2 controls the density, and that "I" controls
whether the speed changes *when the density changes*.
I've also found on my system a TEAC document for the FD505. It clearly
states that pin 2 is the "HD IN" density select input. And a document
>from Don Maslin's archive that describes the pins and jumpers for an
"FD-55GFR" (but it doesn't say which suffix). It, too, clearly says
that pin 2 is the density select, that "LG" controls the polarity of
the density select, and that "I" and "IS" control how this affects the
speed ("I" to determine if the speed changes at all, in response to
density changes, and "IS" controls whether that is latched once the
drive is selected).
--
Pete Peter Turnbull
Network Manager
University of York
>From: "Pete Turnbull" <pete at dunnington.u-net.com>
>
>On Mar 14 2005, 9:18, Dwight K. Elvey wrote:
>
>> Don't use heat sink grease. That has fillers to
>> make it thermally conductive. Use the clear gel stuff.
>> Dow Corning #4 works wonders and doesn't harm any of
>> the electrical stuff. I actually use SilGlyde that I
>> got at the automotive shop. It works quite well.
>
>I still wouldn't use silicon grease, because it creeps over time, and
>can cause all sorts of problems, often at some distance from where it
>was originally put.
>
>--
>Pete Peter Turnbull
> Network Manager
> University of York
>
Hi
Yes, it does creep. I just wonder what problems you refer to.
Dwight
On Mar 14 2005, 12:19, woodelf wrote:
> der Mouse wrote:
>
> >By the "byte = addressing unit" definition? It's been a while since
I
> >had a PDP-8 (I had an -8/f but I long ago gave it to a collector
much
> >more serious than I), but I'm fairly sure the addressing unit was
the
> >12-bit word.
> >
> >
> Addressing unit is WORDS... How ever text can and often was packed in
6
> bit nibbles?
> The real gotya on the old machines... UPPER CASE ASCII ONLY.
Who told you that? It's true of Teletype ASR33s, but not of the
machines themselves. I've happily done things in mixed-case ASCII on
my PDP-8/E.
--
Pete Peter Turnbull
Network Manager
University of York
On Mar 14 2005, 9:18, Dwight K. Elvey wrote:
> Don't use heat sink grease. That has fillers to
> make it thermally conductive. Use the clear gel stuff.
> Dow Corning #4 works wonders and doesn't harm any of
> the electrical stuff. I actually use SilGlyde that I
> got at the automotive shop. It works quite well.
I still wouldn't use silicon grease, because it creeps over time, and
can cause all sorts of problems, often at some distance from where it
was originally put.
--
Pete Peter Turnbull
Network Manager
University of York
---------------Original Message:
Date: Mon, 14 Mar 2005 11:41:42 -0500
From: "John Allain" <allain at panix.com>
Subject: Re: Age
Let me point out that Jay had specifically mentioned this
thread as one of the annoyingly off-topic ones.
It's even worse now that people are off the track twice,
not even keeping to the first diverted topic.
John A.
---------------Reply:
With all due respect to Jay and the moderators, I think
it's a pretty unfriendly list if we're not even allowed to get
to know a little about each other.
I see that this thread is also on CCtech, so I assume that
the moderators do deem it as on-topic; we're certainly all
over ten years old, very much related to computers, and
some of us are most definitely "classic"s.
I suggest that we leave it up to Jay & the other moderators
to let us know when a thread has strayed too far, and, when
they do, act accordingly.
mike
BTW: Add me to the 59 year olds, if I'm not already there.
I have some 9-track mag tapes, mostly 1600bpi but a couple are 800bpi
or 6250bpi. They were made under 4.2BSD Unix on a DEC Vax 11/780 in
about 1986. They are "tar" tapes, blocking factor 20. The contents are
my C programs written then, academic papers I wrote then, and my email
>from then. I want to get the data off the tapes. I am only interested
in the ASCII data, and not any executable files. (The physical tapes
are up for grabs, and some cost me $25 each back then, "Graham Magnetics
Ultra-Mag" certified 100% error free for 25 years.) Is there a kind,
generous, and tape-drive equipped soul out there that would help me out?
A reply like "Only the 800bpi" or "Only the 6250bpi" would be welcome.
Destination: my friend's FTP server, CD-R, DVD-R, or whatever.
Compensation: I have some PDP-11 style hex boards, some of them prototypes.
I have the controller for a DEC RF-11 fixed head disk. I have a "certified
error free", new old stock, 80MB disk pack for a CDC 9762 (SMD). Back in
1985 2.8 BSD on a PDP-11 needed an error free disk pack. I have a RK05
disk pack. I am unemployed at the moment, but could still pay something,
and shipping. Maybe I can repay the favor with my time. I am pretty good
at writing websites, including Flash. Maybe you have to work on the
"dark side" sometimes, and I can ease your pain. I am good at most things
>from uncle Bill, including Windows 2003 server clusters, Terminal Services,
and applications large and small. I study Japanese and other languages, and
software for that study. Also, I am an expert in auto-feed document scanners
and document management/capture software.
richard bristol // email: bristol22 [at] softhome [dot] net
Just found a terrific resource:
http://www.fileformat.info/
Has tons of information on file formats (mostly graphics, but also some
text and markup formats). Searchable, with links to specifications and
such.
Might be useful when trying to decode an old file format you're not
familiar with.
--
Sellam Ismail Vintage Computer Festival
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