29 Oct
2008
29 Oct
'08
3:56 a.m.
I received this request for information on a core memory stack - does
anyone recognize it? I passed on some general info to him about core
memory and how they work.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
---------- Forwarded message ----------
Date: Tue, 28 Oct 2008 20:36:53 EDT
From: BALLSHOP at aol.com
To: mloewen at cpumagic.scol.pa.us
Subject: 40k Ferrite Memory Core
Hello,
I was hoping you could help me figure out what I have here. I bought it an
estate and it had a note attached that said "40k Ferrite Memory Core".
It's
pretty amazing to look at, there are thousands of tiny wires and it has
little black "doughnuts" at the intersection of each wire. Any help in
identifying this would be greatly appreciated.
Thank You,
Scott
http://www.thegolfballshop.com/oct28/1.jpg
http://www.thegolfballshop.com/oct28/2.jpg
http://www.thegolfballshop.com/oct28/3.jpg
http://www.thegolfballshop.com/oct28/4.jpg
http://www.thegolfballshop.com/oct28/5.jpg
29 Oct
29 Oct
4:11 a.m.
Mike Loewen wrote:
I received this request for information on a core memory stack -
does anyone recognize it? I passed on some general info to him about
core memory and how they work.
I have no idea, but 40K sounds more like the
original selling price. The
big question here is
the word width on the stack - Core memory tends to come in 4K blocks x N.
5:23 a.m.
I counted 52 wires x 52 wires in the top plane
I counted either 20 or 19 total planes
In looking at the photo, it appears that there are 2 of those wires thru
each core, so this is 26*26*20 or 13520 bits total
The connector marked X has 40 conductors. I would assume there is also
a Y connector, and maybe fewer sense lines? maybe only 1 sense line per
plane?
This looks a lot in size and constructions as many 50's era core stacks
I have seen, but that and a quarter will get you a cup or coffee
(somewhere).
Jim
bfranchuk at jetnet.ab.ca wrote:
Mike Loewen wrote:
I received this request for information on a core memory stack -
does anyone recognize it? I passed on some general info to him about
core memory and how they work.
I have no idea, but 40K sounds more like the
original selling price.
The big question here is
the word width on the stack - Core memory tends to come in 4K blocks x N.
8:38 a.m.
On 29/10/2008 05:23, jim s wrote:
I counted 52 wires x 52 wires in the top plane
I counted either 20 or 19 total planes
I count 50 x 40, and 20 planes. I think you need glasses, Jim :-)
In looking at the photo, it appears that there are 2
of those wires thru
each core, so this is 26*26*20 or 13520 bits total
I only see one X and one Y plus the sense wire through each core (and
the cores are laid out like that), so I make it 2000 x 20 = 40000.
The connector marked X has 40 conductors. I would
assume there is also
a Y connector, and maybe fewer sense lines?
5.jpg shows 50 Y connections.
maybe only 1 sense line per plane?
That's normal.
--
Pete Peter Turnbull
Network Manager
University of York
7:55 p.m.
Pete Turnbull wrote:
On 29/10/2008 05:23, jim s wrote:
My read on this is it's a (X=40)*(Y=48) matrix, going by the number of pins on
the X&Y connectors, with 21 planes. I count 52 pins on the Y-side of each plane
of the actual matrix. This makes sense as the extra 4 pins (52-48) would be 2
for the sense line and 2 for the inhibit line of each plane. (The sense and
inhibit connections do not come out to the connectors, there would have been
additional wires connecting down the stack when installed). In
http://www.thegolfballshop.com/oct28/3.jpg, one can see there are 4 wires
through each core: X, Y, sense (diagonal), and inhibit (parallel to X), making
it a pure 3D, 4-wire construction (the loopbacks for the inhibit lines are also
visible).
Given other aspects of it's construction (in part, the diagonal sense line) I
think a 3-wire setup would be have been problematic or impossible.
It does give the impression of being 50's-era construction, probably from a
tube machine.
Very pretty, I hope it doesn't get broken up, as intact 3D-stacks like that are
pretty rare these days.
I counted 52 wires x 52 wires in the top plane
I counted either 20 or 19 total planes
I count 50 x 40, and 20 planes. I think you need glasses, Jim :-)
In looking at the photo, it appears that there
are 2 of those wires thru
each core, so this is 26*26*20 or 13520 bits total
I only see one X and one Y plus the sense wire through each core (and
the cores are laid out like that), so I make it 2000 x 20 = 40000.
The connector marked X has 40 conductors. I
would assume there is also
a Y connector, and maybe fewer sense lines?
5.jpg shows 50 Y connections.
maybe only 1 sense line per plane?
That's normal. 
7:05 p.m.
Brent Hilpert wrote:
Pete Turnbull wrote:
I agree about the hopes of it not being broken up.
When I see these, I always have the urge to want to create some logic to drive
it and to "see" it work. Not a particularly useful project, but interesting...
Thanks for your analysis!
On 29/10/2008 05:23, jim s wrote:
My read on this is it's a (X=40)*(Y=48) matrix, going by the number of pins on
the X&Y connectors, with 21 planes. I count 52 pins on the Y-side of each plane
of the actual matrix. This makes sense as the extra 4 pins (52-48) would be 2
for the sense line and 2 for the inhibit line of each plane. (The sense and
inhibit connections do not come out to the connectors, there would have been
additional wires connecting down the stack when installed). In
http://www.thegolfballshop.com/oct28/3.jpg, one can see there are 4 wires
through each core: X, Y, sense (diagonal), and inhibit (parallel to X), making
it a pure 3D, 4-wire construction (the loopbacks for the inhibit lines are also
visible).
Given other aspects of it's construction (in part, the diagonal sense line) I
think a 3-wire setup would be have been problematic or impossible.
It does give the impression of being 50's-era construction, probably from a
tube machine.
Very pretty, I hope it doesn't get broken up, as intact 3D-stacks like that are
pretty rare these days.
I counted 52 wires x 52 wires in the top plane
I counted either 20 or 19 total planes
I count 50 x 40, and 20 planes. I think
you need glasses, Jim :-)
In looking at the photo, it appears that there
are 2 of those wires thru
each core, so this is 26*26*20 or 13520 bits total
I only see one X and one Y plus
the sense wire through each core (and
the cores are laid out like that), so I make it 2000 x 20 = 40000.
The connector marked X has 40 conductors. I
would assume there is also
a Y connector, and maybe fewer sense lines?
5.jpg shows 50 Y connections.
maybe only 1 sense line per plane?
That's normal. 
7:52 p.m.
Brent wrote:
My read on this is it's a (X=40)*(Y=48) matrix,
going by the number of
pins on
the X&Y connectors, with 21 planes. I count 52 pins
on the Y-side of
each plane
of the actual matrix. This makes sense as the extra 4
pins (52-48)
would be 2
for the sense line and 2 for the inhibit line of each
plane. (The sense
and
inhibit connections do not come out to the connectors,
there would have
been
additional wires connecting down the stack when
installed). In
http://www.thegolfballshop.com/oct28/3.jpg, one can see there are 4
wires
through each core: X, Y, sense (diagonal), and inhibit
(parallel to X),
making
it a pure 3D, 4-wire construction (the loopbacks for
the inhibit lines
are also
visible).
I agree with Brent's analysis. I too counted 21 planes, which seems a
bit odd, as typically each plane represented one bit in a word
structure, which would indicate a 21-bit word...not something that
matches up with commonly-used word sizes in 50's/60's era computers (12,
16, 18, 20, 24, 32, 36, 48, 60 or 64 bits). Perhaps some of the planes
have already been removed? It is possible that whatever machine used
this stack didn't use the "bit per plane" methodology, and instead used
a 48-bit word (Y aspect of matrix), which would mean that each plane
held 40 words, for a total of 40*21 (840) words of 48-bits each. This
stack would likely be just one of many used in whatever computer it was
part of, in order to have sufficient memory to be useful. It is also
possible that this stack was used alone in some type of peripheral
device. Frequently devices like line printers, rotating memory
controllers, and other peripherals of the '50's and early '60's used
smaller arrays of core for buffering purposes, which may account for its
rather unusual arrangement.
It does give the impression of being 50's-era
construction, probably
from a
tube machine.
I figure late '50's/early '60's. By the mid-60's, the size of the
ferrite cores had been dramatically reduced. While the general
construction was similar (in terms of 3D core stacks like this one),
their physical size was significantly smaller by the mid-'60's. The
reduction in the physical size of the ferrite cores was somewhat
mandated by the use of transistorized driver circuitry. The amount of
current required to "flip" a larger diameter core was sufficiently high
that tube-type driver circuit was required in the early days of
transistors. As the cores got smaller, so did the current requirements,
which led to the practicality of transistorized X/Y/Inhibit drive
circuits. The cores in this stack are large enough that as Brent
suggests, the machine may have (at least) had tube-based drive
circuitry, if not being a completely tube-based machine.
Later, the three-dimensional aspect of core memory was changed, such
that multiple arrays were woven into the same plane of core, making the
core array fit on a single circuit board (typically with additional
board(s) that provided the address decoding, constant current source,
X&Y drive, sense, and inhibit functionality) in a 2-dimensional
arrangement.
Whatever this stack is from, it is definitely a work of art that should
be preserved intact. Like Brent, I sincerely hope that it doesn't end
up being reduced to 21 individual planes to "optimize" its sales value
on whatever venue it is marketed under.
Rick Bensene
http://oldcalculatormuseum.com (where some of the old calculators have
core memory, some 3D, and some 2D)
8:30 p.m.
On 29 Oct 2008 at 12:52, Rick Bensene wrote:
I agree with Brent's analysis. I too counted 21
planes, which seems a
bit odd, as typically each plane represented one bit in a word
structure, which would indicate a 21-bit word...not something that
matches up with commonly-used word sizes in 50's/60's era computers (12,
16, 18, 20, 24, 32, 36, 48, 60 or 64 bits).
An extra parity bit per word was very common(some Seymour Cray boxes
excepted). My guess is this might be from a GE 200-series mainframe.
Can one still get ferrite cores with hard magnetization curves for
logic any more? I've always had this secret desire to play with
magnetic core logic (not memory).
Cheers,
Chuck
8:52 p.m.
Hi Chuck,
Could you PM me off list about magnetic core logic if interested.
gavin.melville at acclipse.co.nz
Regards,
Gavin.
--------------------------------------------------
From: "Chuck Guzis" <cclist at sydex.com>
Sent: Thursday, October 30, 2008 9:30 AM
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: RE: 40k Ferrite Memory Core
On 29 Oct 2008 at 12:52, Rick Bensene wrote:
I agree with Brent's analysis. I too counted
21 planes, which seems a
bit odd, as typically each plane represented one bit in a word
structure, which would indicate a 21-bit word...not something that
matches up with commonly-used word sizes in 50's/60's era computers (12,
16, 18, 20, 24, 32, 36, 48, 60 or 64 bits).
An extra parity bit per word was very common(some Seymour Cray boxes
excepted). My guess is this might be from a GE 200-series mainframe.
Can one still get ferrite cores with hard magnetization curves for
logic any more? I've always had this secret desire to play with
magnetic core logic (not memory).
Cheers,
Chuck
8:43 p.m.
Hi All,
This might help date it. The Mullard core in these photos was purchased in
1960, and the planes are 48 x 48, 100 layers. So far I've resisted the
temptation to cut it up and make some real money out of it.
http://www.flickr.com/photos/8788341 at N05/1799948181/
Regards,
Gavin Melville
--------------------------------------------------
From: "Rick Bensene" <rickb at bensene.com>
Sent: Thursday, October 30, 2008 8:52 AM
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: RE: 40k Ferrite Memory Core
Brent wrote:
My read on this is it's a (X=40)*(Y=48)
matrix, going by the number of
pins on
the X&Y connectors, with 21 planes. I count 52
pins on the Y-side of
each plane
of the actual matrix. This makes sense as the
extra 4 pins (52-48)
would be 2
for the sense line and 2 for the inhibit line of
each plane. (The sense
and
inhibit connections do not come out to the
connectors, there would have
been
additional wires connecting down the stack when
installed). In
http://www.thegolfballshop.com/oct28/3.jpg, one can see there are 4
wires
through each core: X, Y, sense (diagonal), and
inhibit (parallel to X),
making
it a pure 3D, 4-wire construction (the loopbacks
for the inhibit lines
are also
visible).
I agree with Brent's analysis. I too counted 21 planes, which seems a
bit odd, as typically each plane represented one bit in a word
structure, which would indicate a 21-bit word...not something that
matches up with commonly-used word sizes in 50's/60's era computers (12,
16, 18, 20, 24, 32, 36, 48, 60 or 64 bits). Perhaps some of the planes
have already been removed? It is possible that whatever machine used
this stack didn't use the "bit per plane" methodology, and instead used
a 48-bit word (Y aspect of matrix), which would mean that each plane
held 40 words, for a total of 40*21 (840) words of 48-bits each. This
stack would likely be just one of many used in whatever computer it was
part of, in order to have sufficient memory to be useful. It is also
possible that this stack was used alone in some type of peripheral
device. Frequently devices like line printers, rotating memory
controllers, and other peripherals of the '50's and early '60's used
smaller arrays of core for buffering purposes, which may account for its
rather unusual arrangement.
It does give the impression of being 50's-era
construction, probably
from a
tube machine.
I figure late '50's/early '60's. By the mid-60's, the size of the
ferrite cores had been dramatically reduced. While the general
construction was similar (in terms of 3D core stacks like this one),
their physical size was significantly smaller by the mid-'60's. The
reduction in the physical size of the ferrite cores was somewhat
mandated by the use of transistorized driver circuitry. The amount of
current required to "flip" a larger diameter core was sufficiently high
that tube-type driver circuit was required in the early days of
transistors. As the cores got smaller, so did the current requirements,
which led to the practicality of transistorized X/Y/Inhibit drive
circuits. The cores in this stack are large enough that as Brent
suggests, the machine may have (at least) had tube-based drive
circuitry, if not being a completely tube-based machine.
Later, the three-dimensional aspect of core memory was changed, such
that multiple arrays were woven into the same plane of core, making the
core array fit on a single circuit board (typically with additional
board(s) that provided the address decoding, constant current source,
X&Y drive, sense, and inhibit functionality) in a 2-dimensional
arrangement.
Whatever this stack is from, it is definitely a work of art that should
be preserved intact. Like Brent, I sincerely hope that it doesn't end
up being reduced to 21 individual planes to "optimize" its sales value
on whatever venue it is marketed under.
Rick Bensene
http://oldcalculatormuseum.com (where some of the old calculators have
core memory, some 3D, and some 2D)
11:25 p.m.
On 29/10/2008 19:52, Rick Bensene wrote:
I agree with Brent's analysis. I too counted 21
planes, which seems a
bit odd, as typically each plane represented one bit in a word
structure, which would indicate a 21-bit word...not something that
matches up with commonly-used word sizes in 50's/60's era computers (12,
16, 18, 20, 24, 32, 36, 48, 60 or 64 bits).
It looks pretty intact, and I don't think anything's been stripped.
However, while I count 21 layers (image 2 and image 4) in the
construction, the top layer has no cores (plain to see in images 3 and
4), so there are 20 planes by my reckoning.
And counting rows and columns of cores (not just the wires), I see 40 x
50 (you can easily count them in image 4), which matches the X and Y
numbering on the connectors. So I still reckon that stack is 2000 words
x 20 bits.
--
Pete Peter Turnbull
Network Manager
University of York
30 Oct
30 Oct
2:51 a.m.
I've got one of those on my desk; see
http://www.ece.mcgill.ca/~jthiem/IMG_1904.jpg
I counted 32 planes (on the stack +1 separate), each with 64x64
(=4096) cores. Not visible on the picture between the black plates is
the massive bunch of cables coming out. A 500GiB 3.5in drive for size
comparison next to it.
Note while I have those cores, I can't morally claim to own them.
They were in a display case here in the ECE dept. at McGill (der Mouse
might know more about it, he's been in this building longer than I
have, albeit 3 floors down). The display case showed a bit of the
evolution of storage... more useful when undergrads still came in
here. The display case got dismantled at some point and the contents
moved into a storage room - recently the storage room got cleared out
to become part of a new lab and the contents were mostly to be junked
- so I snagged the cores.
Joe.
---
Joachim Thiemann :: http://www.tsp.ece.mcgill.ca/~jthiem
5:39 a.m.
Pete Turnbull wrote:
On 29/10/2008 19:52, Rick Bensene wrote:
Agreed, looks like the upper 21st 'plane' is just a header for the address wires.
I had arrived at y=48 from looking at the blurry numbers on the Y
connector on photo 5, but a recount indicates 50.
That left me wondering where the 4 connections for the sense and inhibit
wires are: looking again at the other photos, it appears there are two extra
pins on *each* axis (42 & 52) of each plane, so 4 extra pins per plane.
(In photo 4, looking down the planes starting at the left end of the row of
yellow wires one can see the cut-off wires soldered to the pins of what should
be either the sense or inhibit lines.)
I agree with Brent's analysis. I too counted
21 planes, which seems a
bit odd, as typically each plane represented one bit in a word
structure, which would indicate a 21-bit word...not something that
matches up with commonly-used word sizes in 50's/60's era computers (12,
16, 18, 20, 24, 32, 36, 48, 60 or 64 bits).
It looks pretty intact, and I don't think anything's been stripped.
However, while I count 21 layers (image 2 and image 4) in the
construction, the top layer has no cores (plain to see in images 3 and
4), so there are 20 planes by my reckoning.
And counting rows and columns of cores (not just the wires), I see 40 x
50 (you can easily count them in image 4), which matches the X and Y
numbering on the connectors. So I still reckon that stack is 2000 words
x 20 bits.
8:12 a.m.
On 30/10/2008 05:39, Brent Hilpert wrote:
That left me wondering where the 4 connections for the
sense and inhibit
wires are: looking again at the other photos, it appears there are two extra
pins on *each* axis (42 & 52) of each plane, so 4 extra pins per plane.
Yes, I saw that too, but forgot to post it. I wonder why there's not a
connector block for all those.
--
Pete Peter Turnbull
Network Manager
University of York
29 Oct
29 Oct
8:24 a.m.
On 29/10/2008 03:56, Mike Loewen wrote:
I received this request for information on a core memory stack - does
anyone recognize it? I passed on some general info to him about core
memory and how they work.
Just counting the X and Y wires and the stack height suggests it's 40K
bits, so it could be around 4K words. It looks just like one a friend
has, so I'll ask next time I see him.
--
Pete Peter Turnbull
Network Manager
University of York
12:30 p.m.
I'm not any help in determining the machine that core
came from, but I do think that it is beautiful! Part
of what makes it cool to me is the three dimensionality
of the entire stack. And when I saw the final picture,
the one which had the soda can in it for reference, the
full size of the stack was realized!
What is to become of this core stack?
Mike Loewen wrote:
I received this request for information on a core memory stack - does
anyone recognize it? I passed on some general info to him about core
memory and how they work.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
---------- Forwarded message ----------
Date: Tue, 28 Oct 2008 20:36:53 EDT
From: BALLSHOP at aol.com
To: mloewen at cpumagic.scol.pa.us
Subject: 40k Ferrite Memory Core
Hello,
I was hoping you could help me figure out what I have here. I bought
it an
estate and it had a note attached that said "40k Ferrite Memory
Core". It's
pretty amazing to look at, there are thousands of tiny wires and it has
little black "doughnuts" at the intersection of each wire. Any help in
identifying this would be greatly appreciated.
Thank You,
Scott
http://www.thegolfballshop.com/oct28/1.jpg
http://www.thegolfballshop.com/oct28/2.jpg
http://www.thegolfballshop.com/oct28/3.jpg
http://www.thegolfballshop.com/oct28/4.jpg
http://www.thegolfballshop.com/oct28/5.jpg
1:04 p.m.
Tom Uban Wrote:
What is to become of this core stack?
Per my discussion with the owner it's headed for eBay shortly. . . hopefully
intact.
Erik Klein
www.vintage-computer.com
www.vintage-computer.com/vcforum - The Vintage Computer Forums
marketplace.vintage-computer.com - The Vintage Computer and Gaming
Marketplace
1:16 p.m.
Please be sure to give us the heads up when it is listed.
Erik Klein wrote:
Tom Uban Wrote:
What is to become of this core stack?
Per my discussion with the owner it's headed for eBay shortly. . . hopefully
intact.
Erik Klein
www.vintage-computer.com
www.vintage-computer.com/vcforum - The Vintage Computer Forums
marketplace.vintage-computer.com - The Vintage Computer and Gaming
Marketplace
30 Oct
30 Oct
1:07 p.m.
Tom Uban Wrote:
Please be sure to give us the heads up when it is
listed.
Here ya'll go: eBay Item Number 330282554507
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MESELX:IT…
=330282554507
I'm sure it'll be out of my price range soon. :)
Erik Klein
www.vintage-computer.com
www.vintage-computer.com/vcforum - The Vintage Computer Forums
marketplace.vintage-computer.com - The Vintage Computer and Gaming
Marketplace
1:26 p.m.
New subject: Core Beads (was Re: 40k Ferrite Memory Core)
For the person who was looking for core memory beads, I
noticed a few boxes of them while searching eBay for core
memory stuff...
No affiliation, etc.
4:16 p.m.
New subject: Core Beads (was Re: 40k Ferrite Memory Core)
On 30 Oct 2008 at 8:26, Tom Uban wrote:
For the person who was looking for core memory beads,
I
noticed a few boxes of them while searching eBay for core
memory stuff...
'Twas I. Not the teeny core memory beads, but larger hard ferrite
toroids usable for magnetic core logic use; i.e. the ability to put
several windings on a core.
FWIW, In my desk drawer, along with some other arcane stuff,I've got
a frame from what I believe was an old Philco system. Much larger
and much much less dense than the "40K" module shown. Still, the
cores are way too small for what I'd need.
Cheers,
Chuck
3 Nov
3 Nov
5:23 p.m.
New subject: Core Beads (was Re: 40k Ferrite Memory Core)
For logic use, do you need square loop material or transformer-type (low hysteresis)
material? The latter is readily available in a multitude of sizes.
paul
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf
Of Chuck Guzis
Sent: Thursday, October 30, 2008 12:16 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Core Beads (was Re: 40k Ferrite Memory Core)
On 30 Oct 2008 at 8:26, Tom Uban wrote:
For the person who was looking for core memory beads,
I
noticed a few boxes of them while searching eBay for core
memory stuff...
'Twas I. Not the teeny core memory beads, but larger hard ferrite
toroids usable for magnetic core logic use; i.e. the ability to put
several windings on a core.
FWIW, In my desk drawer, along with some other arcane stuff,I've got
a frame from what I believe was an old Philco system. Much larger
and much much less dense than the "40K" module shown. Still, the
cores are way too small for what I'd need.
Cheers,
Chuck
8 Nov
8 Nov
10:45 p.m.
Erik Klein wrote:
Tom Uban Wrote:
So, it just went for $1,180 (!!). That's $59 per plane.
As expensive as it was, I don't know if it's enough to keep us from now seeing
20 planes filtering out onto ebay...
Please be sure to give us the heads up when it is
listed.
Here ya'll go: eBay Item Number 330282554507
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MESELX:IT…
=330282554507
I'm sure it'll be out of my price range soon. :) 
29 Oct
29 Oct
5:42 p.m.
I thought I recognized it, until I saw the last photo with the
soda can. Good heavens...that stack is HUGE!!
I have one that's nearly identical, but about 1/4 the size of this
one. I was told it was from an early IBM 360, but I've still not
verified that.
-Dave
On Oct 28, 2008, at 11:56 PM, Mike Loewen wrote:
I received this request for information on a core
memory stack -
does anyone recognize it? I passed on some general info to him
about core memory and how they work.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
---------- Forwarded message ----------
Date: Tue, 28 Oct 2008 20:36:53 EDT
From: BALLSHOP at aol.com
To: mloewen at cpumagic.scol.pa.us
Subject: 40k Ferrite Memory Core
Hello,
I was hoping you could help me figure out what I have here. I
bought it an
estate and it had a note attached that said "40k Ferrite Memory
Core". It's
pretty amazing to look at, there are thousands of tiny wires and
it has
little black "doughnuts" at the intersection of each wire. Any
help in
identifying this would be greatly appreciated.
Thank You,
Scott
http://www.thegolfballshop.com/oct28/1.jpg
http://www.thegolfballshop.com/oct28/2.jpg
http://www.thegolfballshop.com/oct28/3.jpg
http://www.thegolfballshop.com/oct28/4.jpg
http://www.thegolfballshop.com/oct28/5.jpg
--
Dave McGuire
Port Charlotte, FL
7:28 p.m.
Mike Loewen wrote:
I received this request for information on a core memory stack - does
anyone recognize it?
Is there any info on country of origin? That might narrow it down a lot...
I think it probably is late '50s, as core seemed to get a lot more compact in
the '60s, and a single stack of 40k capacity would have probably been unusual
on earlier '50s systems.
Problem is, it looks like a lot of stacks that I've seen on machines around
that time - same materials, same white lettering etc.; as we know the capacity
then perhaps knowing which country's system it was would be enough (I'm not
sure if it's possible to guess at machine word length purely from the core
organisation?)
cheers
Jules
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bfranchuk＠jetnet.ab.ca -
cclist＠sydex.com -
classiccmp＠vintage-computer.com -
gavin.melville＠acclipse.co.nz -
hilpert＠cs.ubc.ca -
joachim.thiemann＠gmail.com -
jules.richardson99＠gmail.com -
jws＠jwsss.com -
mcguire＠neurotica.com -
mloewen＠cpumagic.scol.pa.us -
Paul_Koning＠Dell.com -
pete＠dunnington.plus.com -
rickb＠bensene.com -
uban＠ubanproductions.com