31 Jan
2017
31 Jan
'17
12:46 p.m.
Hi,
Can someone identify this circuit board? It's some sort of magnetic core
memory. I've had this for ages and I've always wondered what it is and
where it comes from.
http://lookpic.com/O/i2/366/iAFq4mLF.jpeg
Best regards
1 Feb
1 Feb
4:18 a.m.
On Feb 1, 2017 1:12 AM, "ilco havermout" <ilcohn3 at gmail.com> wrote:
Hi,
Can someone identify this circuit board? It's some sort of magnetic core
memory. I've had this for ages and I've always wondered what it is and
where it comes from.
http://lookpic.com/O/i2/366/iAFq4mLF.jpeg
Best regards
Could this be the core memory control card that snaps onto a larger core
board? Or some other type of board, same idea. Here is an example
http://www.vintagecomputer.net/inforex/inforex_controller_dataram_installed…
8:57 a.m.
Mr. Havermout wrote:
Can someone identify this circuit board? It's some
sort of magnetic core
memory. I've had this for ages and I've always wondered what it is and
where it comes from.
http://lookpic.com/O/i2/366/iAFq4mLF.jpeg
Whatever this was, it appears that it has been scavenged for parts over time. Many
components appear to be missing.
It seems to me from looking at the board carefully that it could be a small wire-rope
ROM, or, perhaps the cores (one module has its cover removed exposing the large ferrite
rings) serve as pulse transformers for magnetic core that resides on another circuit
board.
If it is a small wire-rope read-only memory, it appears that it could be a 16x16 ROM,
perhaps hard wired for some kind of small bootstrap loader or the like.
It looks like there are 16 wire drivers (two of the driver transistors are missing), and
16 sense amplifiers.
If it isn't a ROM, then it could be a driver/sense amp board, with some row/column
driver transistors, steering diodes, and pulse transformers for a core array located on
another board plugged into the backplane of whatever this was in.
I'm not entirely sure which one of these it is, but it's likely one or the other.
-Rick
--
Rick Bensene
The Old Calculator Museum
http://oldcalcualtormuseum.com
10:02 a.m.
On Feb 1, 2017, at 11:57 AM, Rick Bensene <rickb at
bensene.com> wrote:
Mr. Havermout wrote:
If it's a core-rope ROM, which seems plausible, then it would be 256 x 16. Core rope
uses 2 select ("inhibit") lines/drivers per address bit. So 16 drivers means 8
address bits, i.e., 2^8 words.
paul
Can someone identify this circuit board? It's
some sort of magnetic core
memory. I've had this for ages and I've always wondered what it is and
where it comes from.
http://lookpic.com/O/i2/366/iAFq4mLF.jpeg
Whatever this was, it appears that it has been scavenged for parts over time. Many
components appear to be missing.
It seems to me from looking at the board carefully that it could be a small wire-rope
ROM, or, perhaps the cores (one module has its cover removed exposing the large ferrite
rings) serve as pulse transformers for magnetic core that resides on another circuit
board.
If it is a small wire-rope read-only memory, it appears that it could be a 16x16 ROM,
perhaps hard wired for some kind of small bootstrap loader or the like.
It looks like there are 16 wire drivers (two of the driver transistors are missing), and
16 sense amplifiers.
10:06 a.m.
On Feb 1, 2017, at 1:02 PM, Paul Koning <paulkoning
at comcast.net> wrote:
Never mind, that was all wrong. It takes only 2*n wires to select one of 2^n cores in a
core-rope ROM, so far that was correct. But the number of ROM words equals the number of
cores (obviously). So if there are 16 cores that would mean 16 words, but it also means
that only 8 drivers are needed (4 address bits). So there's a puzzle.
paul
On Feb 1, 2017, at 11:57 AM, Rick Bensene
<rickb at bensene.com> wrote:
Mr. Havermout wrote:
If it's a core-rope ROM, which seems plausible, then it would be 256 x 16. Core rope
uses 2 select ("inhibit") lines/drivers per address bit. So 16 drivers means 8
address bits, i.e., 2^8 words. Can someone identify this circuit board? It's
some sort of magnetic core
memory. I've had this for ages and I've always wondered what it is and
where it comes from.
http://lookpic.com/O/i2/366/iAFq4mLF.jpeg
Whatever this was, it appears that it has been scavenged for parts over time. Many
components appear to be missing.
It seems to me from looking at the board carefully that it could be a small wire-rope
ROM, or, perhaps the cores (one module has its cover removed exposing the large ferrite
rings) serve as pulse transformers for magnetic core that resides on another circuit
board.
If it is a small wire-rope read-only memory, it appears that it could be a 16x16 ROM,
perhaps hard wired for some kind of small bootstrap loader or the like.
It looks like there are 16 wire drivers (two of the driver transistors are missing), and
16 sense amplifiers. 
11:02 a.m.
I think it is a register board. Something
to hold data through a power down.
Dwight
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Paul Koning
<paulkoning at comcast.net>
Sent: Wednesday, February 1, 2017 10:06:55 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Please identify this circuit board
On Feb 1, 2017, at 1:02 PM, Paul Koning <paulkoning
at comcast.net> wrote:
Never mind, that was all wrong. It takes only 2*n wires to select one of 2^n cores in a
core-rope ROM, so far that was correct. But the number of ROM words equals the number of
cores (obviously). So if there are 16 cores that would mean 16 words, but it also means
that only 8 drivers are needed (4 address bits). So there's a puzzle.
paul
[http://lookpic.com/O/i2/366/iAFq4mLF.jpeg]
On Feb 1, 2017, at 11:57 AM, Rick Bensene
<rickb at bensene.com> wrote:
Mr. Havermout wrote:
If it's a core-rope ROM, which seems plausible, then it would be 256 x 16. Core rope
uses 2 select ("inhibit") lines/drivers per address bit. So 16 drivers means 8
address bits, i.e., 2^8 words. Can someone identify this circuit board? It's
some sort of magnetic core
memory. I've had this for ages and I've always wondered what it is and
where it comes from.
http://lookpic.com/O/i2/366/iAFq4mLF.jpeg
Whatever this was, it appears that it has been scavenged for parts over time. Many
components appear to be missing.
It seems to me from looking at the board carefully that it could be a small wire-rope
ROM, or, perhaps the cores (one module has its cover removed exposing the large ferrite
rings) serve as pulse transformers for magnetic core that resides on another circuit
board.
If it is a small wire-rope read-only memory, it appears that it could be a 16x16 ROM,
perhaps hard wired for some kind of small bootstrap loader or the like.
It looks like there are 16 wire drivers (two of the driver transistors are missing), and
16 sense amplifiers. 
2 Feb
2 Feb
1:44 a.m.
[Exceptionally top-posting...]
There are two modules each containing eight pulse transformers. That's it.
The left module has the cover removed.
No memory, no register. This board is from 1971, so it would contain some
TTL FFs or RAM (e.g. 7489) for registers.
Christian
On Wed, 1 Feb 2017, dwight wrote:
I think it is a register board. Something
to hold data through a power down.
Dwight
On Feb 1, 2017, at 1:02 PM, Paul Koning
<paulkoning at comcast.net> wrote:
Never mind, that was all wrong. It takes only 2*n wires to select one of 2^n cores in a
core-rope ROM, so far that was correct. But the number of ROM words equals the number of
cores (obviously). So if there are 16 cores that would mean 16 words, but it also means
that only 8 drivers are needed (4 address bits). So there's a puzzle.
paul On Feb 1, 2017, at 11:57 AM, Rick Bensene
<rickb at bensene.com> wrote:
Mr. Havermout wrote:
If it's a core-rope ROM, which seems plausible, then it would be 256 x 16. Core rope
uses 2 select ("inhibit") lines/drivers per address bit. So 16 drivers means 8
address bits, i.e., 2^8 words. Can someone identify this circuit board? It's
some sort of magnetic core
memory. I've had this for ages and I've always wondered what it is and
where it comes from.
http://lookpic.com/O/i2/366/iAFq4mLF.jpeg
Whatever this was, it appears that it has been scavenged for parts over time. Many
components appear to be missing.
It seems to me from looking at the board carefully that it could be a small wire-rope
ROM, or, perhaps the cores (one module has its cover removed exposing the large ferrite
rings) serve as pulse transformers for magnetic core that resides on another circuit
board.
If it is a small wire-rope read-only memory, it appears that it could be a 16x16 ROM,
perhaps hard wired for some kind of small bootstrap loader or the like.
It looks like there are 16 wire drivers (two of the driver transistors are missing), and
16 sense amplifiers.
6:24 a.m.
Are you sure the cores are transformers and not memory
cores?
Dwight
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Christian Corti <cc
at informatik.uni-stuttgart.de>
Sent: Thursday, February 2, 2017 1:44:18 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Please identify this circuit board
[Exceptionally top-posting...]
There are two modules each containing eight pulse transformers. That's it.
The left module has the cover removed.
No memory, no register. This board is from 1971, so it would contain some
TTL FFs or RAM (e.g. 7489) for registers.
Christian
On Wed, 1 Feb 2017, dwight wrote:
I think it is a register board. Something
to hold data through a power down.
Dwight
On Feb 1, 2017, at 1:02 PM, Paul Koning
<paulkoning at comcast.net> wrote:
Never mind, that was all wrong. It takes only 2*n wires to select one of 2^n cores in a
core-rope ROM, so far that was correct. But the number of ROM words equals the number of
cores (obviously). So if there are 16 cores that would mean 16 words, but it also means
that only 8 drivers are needed (4 address bits). So there's a puzzle.
paul On Feb 1, 2017, at 11:57 AM, Rick Bensene
<rickb at bensene.com> wrote:
Mr. Havermout wrote:
If it's a core-rope ROM, which seems plausible, then it would be 256 x 16. Core rope
uses 2 select ("inhibit") lines/drivers per address bit. So 16 drivers means 8
address bits, i.e., 2^8 words. Can someone identify this circuit board? It's
some sort of magnetic core
memory. I've had this for ages and I've always wondered what it is and
where it comes from.
http://lookpic.com/O/i2/366/iAFq4mLF.jpeg
Whatever this was, it appears that it has been scavenged for parts over time. Many
components appear to be missing.
It seems to me from looking at the board carefully that it could be a small wire-rope
ROM, or, perhaps the cores (one module has its cover removed exposing the large ferrite
rings) serve as pulse transformers for magnetic core that resides on another circuit
board.
If it is a small wire-rope read-only memory, it appears that it could be a 16x16 ROM,
perhaps hard wired for some kind of small bootstrap loader or the like.
It looks like there are 16 wire drivers (two of the driver transistors are missing), and
16 sense amplifiers. 
6:38 a.m.
On 02/02/2017 06:24 AM, dwight wrote:
Are you sure the cores are transformers and not
memory
cores?
Dwight
It's pretty obvious to me that there are several turns on each core.
Given the PCB fab date (10/73), there were better methods for keeping
around a few bits than core. If you compare this board with some of
the circuitry found in the EMM bitsavers documentation, it's a pretty
good bet that this was a driver board.
Note that empty pads for a 20-pin 0.600" wide IC also.
--Chuck
1 Feb
1 Feb
9:04 a.m.
On 01/31/2017 02:46 PM, ilco havermout wrote:
Hi,
Can someone identify this circuit board? It's some sort of magnetic core
memory. I've had this for ages and I've always wondered what it is and
where it comes from.
http://lookpic.com/O/i2/366/iAFq4mLF.jpeg
Best regards
That is certainly a part of a core memory system, made by
Electronic Memories. Does the other side of the board have
a core plane on it? Memories from that vintage often have
multiple boards, with select drivers, sense amps, inhibit
drivers, decode logic and timing, as well as the core planes.
Jon
9:18 a.m.
Looks like a driver board (row or column) for an EMM core memory. A lot
of stuff has been scavenged from the board, which makes ID more difficult.
--Chuck
2660
days inactive
2663
days old
11 comments
8 participants
participants (8)
-
billdegnan＠gmail.com -
cc＠informatik.uni-stuttgart.de -
cclist＠sydex.com -
dkelvey＠hotmail.com -
elson＠pico-systems.com -
ilcohn3＠gmail.com -
paulkoning＠comcast.net -
rickb＠bensene.com