On Dec 3, 12:17, Marvin wrote:
> Philip.Belben(a)pgen.com wrote:
> >
> > Eh? Silver solder is certainly very nice, flows well, bonds to a lot
of metals,
> > etc., but isn't it usually _higher_ melting point? Conventional solder
melts at
> > around 450 F, I think. (Anyone have the exact figure?), silver solder
typically
> > at 600.
Yes, yes, no; see below...
> The melting point of solder varies depending on its composition. Eutectic
> solder (63/37) melts at about 361 degrees F and the melting point raises
as
> the percentage of either the lead or tin content raises.
That's not *exactly* true; the solidus point (the temperature at which it
begins to melt) remains almost exactly the same, but the liquidus point
rises. In between, though, the solder is rather pasty. That's great for
old-fashioned plumbing, but it's apt to produce dry joints in electronics,
so for practical purposes, the useful temperature rises just as Marvin
says.
For example, 40/60 solder has a liquidus point of 227C (440F) and 60/40 has
a liquidus point of 188C (370F). Adding certain other metals, especially
bismuth, lowers the melting point, though many other additives, such as
antimony, raise it. According to my Multicore Solder list, the recommended
bit temperature for 40/60 general-purpose electronics solder is 354C
(670F), and for 60/40 it's 308C (585F). Personally, I'm never that
precise; I just twist the setscrew on my Oryx TC irons until they work
right!
"Silver solder" comes in a variety of grades, the ones with the lowest
melting points are ArgoSwift and EasyFlo2 which melt at 600-610C
(1100-1130F, that's a dull red heat). EasyFlo2 is 42% silver, 17% copper,
16% zinc, and 25% cadmium. Most engineering silver solders are
silver+brass based like this. A few are silver-bronze (bronze being an
alloy of copper and tin).
The "silver-loaded" solder Tony and others mentioned is a soft solder
containing 62% tin, 36% lead, and 2% silver. It has a melting point of
179C (354F) and a recommended bit temperature of 300-310C (570-590F).
Other silver/tin/lead solders like Comsol (I bet Tony has come across that)
and LM5 are high-melting point soft solders, with a high lead content.
I've seen them used for fusible resistors and the like.
I expect this is at least four times as much as most of you ever wanted to
know about that silvery-grey stuff that holds the components on...
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
When I was just starting out, I was an operator of about 4 vaxen with VMS 3.somthing (I even wrote
my own command history facility in DCL!) Would be nice to be able to play with that stuff again..
Anybody know of a VAX emulator for IBM machines? Is there a legal way to get VMS for running on
the emulator?
-----Original Message-----
From: John Foust <jfoust(a)threedee.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Friday, December 03, 1999 10:15 AM
Subject: Re: Everyone here should read this.. I thought I'd seen everything.
>
>Flay somebody? We all knew these gold processing plants existed,
>right? I'd never heard a tale of the scope, though. Even still,
>it's clear this factory has volume. There's not enough classic
>computer collectors in the world to rescue all those machines.
>
>We can wish there was a better mechanism for us to be able to
>cherry-pick the make and model we dream of, but the fact is,
>John B. just took a tour of a very large, very efficient,
>and apparently profitable Dumpster.
I just hope I can pull aside as many good minis from the '60s as I can. This
company does not stop cutting for anything. I had no idea so many IBM 30
series? systems get chopped up every week. The 1130 and the 8 bit front
panel computer did break my heart but it's just gold to them. Hopefully this
exercise wil yield some good parts and systems needed. He does get in quite
a bit of documentation with the systems and I will be taking as much of that
as I can. He has a *huge* DEC load coming in next Wednesday so I will be
there on Thursday. I have scrapped quite a few systems my self (and thought
that was bad) but seeing what his site does in one day made me sick.
Will keep everyone updated.
john
>
>- John
>
>
> Would the person who originally requested the David Ahl BASIC source for
> super star trek please e-mail me again? I've misplaced your e-mail. I have
> the scans ready to send. (actually, if anyone else wants copies of these
> scans, let me know and I'll mail them to you too. If there's enough interest
> I'll just stick them on my web page.
Um, "me too" :D
Please, to staylor(a)mrynet.com.
Cheers,
--
Scott G. Akmentins-Taylor InterNet: staylor(a)mrynet.com
MRY Systems staylor(a)mrynet.lv
(Skots Gregorijs Akmentins-Teilors -- just call me "Skots")
----- Labak miris neka sarkans -----
At 05:41 PM 12/2/99 -0500, you wrote:
<big snip>
>he did not want to sell them at first as he was *required* to
>destroy them.
<snip>
>I *agree* to destroy anything I buy from him ;-)
<snip to end>
Very sad story, but typical of our times.
I hope you can rescue some of it.
FWIW: If he's under an "assured destruct" contract, and you're buying from
him,
then you both can be in a lot of hot water if the wrong people find out.
Lance.
> There's also some sentiment opposed to the separation of the gong
> from the rest of the set; it's regarded as a central part of the
> spirit of the collection of instruments. It's akin to putting a
> core memory on the wall, I think. :-)
Not that bad, surely. It's not as if I don't use it!
Anyway, no need to worry. This gong was never in a gamelan, AFAICT. And I have
a saron or two to keep it company (although it turns out the saron is tuned in
slendro, and the gong in pelog. Oh well. I searched for ages to try and find a
melodic instrument tuned in pelog, and failed - and never even checked the gong)
For anyone who goes to Jakarta: the antique market in the Jalan Surabaya is
unmissable as a place to visit, but most of the stuff on sale is far from
genuine. The gong is detectably a fake [*] when you look at it, but I chose it
on listening, not looking. The stand is a blatant fake - a combination of two
incompatible ethnic styles - and judging by the newspaper used in construction,
dates from around January 1997 (I bought the gong in July or August that year)
Philip.
[*] made in several pieces with welded seams that are just visible. Real gongs
are beaten from a single sheet of bronze. For that matter, the notes on the
saron are pieces of bronze plate, bent into shape, when they should be
individually cast...
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--- allisonp(a)world.std.com wrote:
> > Yes. A daughter card for the CPU and a card under the skirt...
>
> Yes, I'd bet that's seriously rare.
I've only ever seen the one.
> > 1 8300 w/16Mb, KDB50+shared RA81, DEBNT
>
> Seriously nice VAX.
Thanks. We got it c. 1989 for VAXBI development. I got to write the firmware
and device driver for our intellegent serial card. I currently have a box in
the basement with 80% of the world's production of it - 8 cards out of 10.
After all the development, it was never a big seller due to the fact that the
world had moved on. At least we priced the card high enough to break even
on the production costs and the cost on the 8300, barely. If you've ever
wondered why VAXBI SCSI cards cost so much, it's because a) they can and b)
nobody ever sold more than a handful of anything for the VAXBI except DEC.
> The only unique thing about the VS2000s I have is they 8mb, 12 and 14mb
> ram respectively.
Isn't it 4Mb, 6Mb, 12Mb and 14Mb? I have a 4Mb add-in card and one that is
half-full, but no 12Mb add-in cards. :-(
> A note on that is MV2000 is not fast mostly due to disk
> IO but adding ram to the 14mb limit does really help if there is any
> swaping going on. Of course finding ram is the real trick.
Indeed. I know that when I looked at expanding my MV2000s, buying a ram card
>from a reseller was always more expensive than the CPU itself.
-ethan
=====
Infinet has been sold. The domain is going away in February.
Please send all replies to
erd(a)iname.com
__________________________________________________
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I spotted nine of them in Skycraft surpus store here in Orlando today.
$5 each. They're marked "untested as is" but they look OK. No, I didn't see
any tapes.
Joe
I need a DASD for IBM 5363, which uses the IBM 0669 ESDI disk. This is
the same type no. as the 115MB used in the IBM 8580 PS/2, but with a
different feature code, and the block size switch set to 512 bytes,
instead of 256 bytes.
I've installed the 8580 variant in the 5363, with switches on the disk
set per the IBM 5363 MIM specs, but the init routine pops an SRC
indicating that the defect map is missing or damaged and refuses to LLF
the disk. I suspect this is due to the fact that the factory defect map
was written with 256 char. blocks instead of 512 char. blocks, but I'm
not sure--and I don't trust the IBM error codes since they aren't
exclusive.
The only variable I haven't eliminated is the drive electronics. Before
I spend time swapping drive boards, I wanted to consult with other folks
who are prone to commit such foolishness and see if anyone had any
wisdom to share.
If the drive boards don't make any difference, my next project is an
attempt to hack the ROM on the 8580's ESDI controller to see if I can
make it work with 512 char. blocks, then try to re-write the defect map.
--
David Wollmann
ICQ: 10742063
>Thanks. We got it c. 1989 for VAXBI development. I got to write the firmware
>and device driver for our intellegent serial card. I currently have a box in
>the basement with 80% of the world's production of it - 8 cards out of 10.
>After all the development, it was never a big seller due to the fact that the
>world had moved on.
Aha! Another VAXBI survivor! The company I used to work for did a quad
IEEE-488 interface and a MIL-STD-1553 interface. I did the firmware for
the IEEE-488 interface (imaging a Z80 looking up user-space addresses
in the page table. Fun!) and the device drivers for both interfaces. We
did hardware debug by running CP/M on one of the IEEE-488 cards; that's
right, I have a VAXBI machine that runs CP/M.
>At least we priced the card high enough to break even
>on the production costs and the cost on the 8300, barely. If you've ever
>wondered why VAXBI SCSI cards cost so much, it's because a) they can and b)
>nobody ever sold more than a handful of anything for the VAXBI except DEC.
We sold about a hundred or so IEEE-488 interfaces. It took many years, but
it did manage to climb out of the red ink. The problem is that the bloody
thing simply will not die; I've been averaging about one inquiry a quarter
on it.
Roger Ivie
ivie(a)cc.usu.edu
