27 Jul
2025
27 Jul
'25
11:41 a.m.
Hi all,
I just spotted an auction on eBay for 40 IBM SMS cards.
It sold for over $2,000 (!)
Does anyone know if this reflects collector value or the value of the
gold content?
Also, what’s the current value of a set of SMS cold contacts?
Thanks,
Henk
www.ibmsystem3.nl
27 Jul
27 Jul
3:15 p.m.
On 7/27/25 13:41, Henk Stegeman via cctalk wrote:
Hi all,
I just spotted an auction on eBay for 40 IBM SMS cards.
It sold for over $2,000 (!)
Does anyone know if this reflects collector value or the
value of the gold content?
Also, what’s the current value of a set of SMS cold contacts?
OH, no WAY on the gold content. SMS was used in the early
days where gold went for $28/Oz. But, it couldn't have been
put on very thick for card fingers. Some other
manufacturers used gold as the etch resist, as it was
impervious to ferric chloride. But, still, those SMS cards
would only have a couple US$ of gold on the whole lot of 40!
Jon
3:43 p.m.
maybe somebody is restoring a computer and recognized a card they need....
LOL
On Sun, Jul 27, 2025 at 2:05 PM Henk Stegeman via cctalk <
cctalk(a)classiccmp.org> wrote:
Hi all,
I just spotted an auction on eBay for 40 IBM SMS cards.
It sold for over $2,000 (!)
Does anyone know if this reflects collector value or the value of the
gold content?
Also, what’s the current value of a set of SMS cold contacts?
Thanks,
Henk
www.ibmsystem3.nl
--
--Carey
28 Jul
28 Jul
7:40 a.m.
On 7/27/25 17:43, Carey Schug via cctalk wrote:
maybe somebody is restoring a computer and recognized
a card they need....
LOL
SMS cards should be VERY easy to repair. The transistors
are mostly 2N404 (Germanium PNP) IIRC. And, diodes are
glass Germanium types. The boards are single-sided, with no
plated through holes, so the traces are a bit fragile.
Jon
10:26 a.m.
Do you have a good guess of what part they used for the faster drift-field tranststors?
Not having any such in 1979 when I repaired some cards, I put in gold-doped silicon
2N4258’s and reduced the reverse bias.
Dave Wise
On Jul 28, 2025, at 7:50 AM, Jon Elson via cctalk
<cctalk(a)classiccmp.org> wrote:
On 7/27/25 17:43, Carey Schug via cctalk wrote:
maybe somebody is restoring a computer and
recognized a card they need....
LOL
SMS cards should be VERY easy to repair. The transistors are mostly 2N404
(Germanium PNP) IIRC. And, diodes are glass Germanium types. The boards are
single-sided, with no plated through holes, so the traces are a bit fragile.
Jon
12:24 p.m.
On Mon, 2025-07-28 at 09:40 -0500, Jon Elson via cctalk wrote:
On 7/27/25 17:43, Carey Schug via cctalk wrote:
The Computer History Museum in Sunnyvale CA has two working IBM 1401
computers, made from SMS cards. They say 2N404 isn't quite the same as
the IBM transistors. The seals on the leads of the IBM transistors
contained iron, so they rust and eventually humidity ruins them. IIRC,
the restoration staff at CHM says 2N2313 (or maybe 2N2913) is the
correct replacement (but I might misremember that).
maybe somebody is restoring a computer and
recognized a card they
need....
LOL
SMS cards should be VERY easy to repair. The transistors
are mostly 2N404 (Germanium PNP) IIRC. And, diodes are
glass Germanium types. The boards are single-sided, with no
plated through holes, so the traces are a bit fragile.
Jon
70
days inactive
71
days old
5 comments
5 participants
participants (5)
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Carey Schug -
David Wise -
Henk Stegeman -
Jon Elson -
Van Snyder