> On Feb 2, 2023, at 11:03 AM, Sellam Abraham via cctalk
> wrote:
>
> This discussion on core memory got me thinking:
>
> Is it possible to "read" core memory by examining each core using some kind
> of instrument that would sense its "charge&qu
> On 02/02/2023 10:03 AM CST Sellam Abraham via cctalk
> wrote:
>
>
> This discussion on core memory got me thinking:
>
> Is it possible to "read" core memory by examining each core using some kind
> of instrument that would sense its "charge
This discussion on core memory got me thinking:
Is it possible to "read" core memory by examining each core using some kind
of instrument that would sense its "charge" (or lack thereof)
non-destructively?
Could a piece of paper be placed over a core plane and fine particl
On Sun, Apr 3, 2022 at 4:01 PM Will Cooke via cctech
wrote:
> > Gentle plug for https://www.daliborfarny.com/.
>
> I got excited by that until I saw there was no pricing and no
> availability. :-(
>
I know :-P I binge-watched their youtube channel (here
On 4/3/2022 10:01 AM, Will Cooke via cctech wrote:
On 04/03/2022 8:34 AM Magnus Ringman via cctech wrote:
On Fri, Apr 1, 2022 at 10:26 PM Marc Howard via cctech <
cct...@classiccmp.org> wrote:
We need to onshore Nixie production now! ;-)
Gentle plug forhttps://www.daliborfarny.com/.
I
> On 04/03/2022 8:34 AM Magnus Ringman via cctech wrote:
>
>
> On Fri, Apr 1, 2022 at 10:26 PM Marc Howard via cctech <
> cct...@classiccmp.org> wrote:
>
> > We need to onshore Nixie production now! ;-)
>
> Gentle plug for https://www.daliborfarny.com/.
I got excited by that until I saw
On Fri, Apr 1, 2022 at 10:26 PM Marc Howard via cctech <
cct...@classiccmp.org> wrote:
> We need to onshore Nixie production now! ;-)
>
Gentle plug for https://www.daliborfarny.com/.
. It would make the core plane simpler at the expense
Wasn't that common in newer core memory days? I mean, there's nothing
special about three-wire core memory with common sense/inhibit lines.
Christian
DEC PDP-8/e core memories have a combined Sense/Inhibit line.
There are only 3 wires through each core donut: X, Y, Sense/Inhibit.
The PDP-8/e core memory is very well described starting at page 3-60 of the
Maintenance Manual Volume 1:
http://www.bitsavers.org/pdf/dec/pdp8/pdp8e/DEC-8E-HMM1A-D
You don’t strictly need an inhibit wire to write cores. You can write the core
with just the addressing lines. The inhibit wire is just there to simplify the
addressing electronics logic in early core memory, so you don’t need to have
per core control of the current in the address lines when
> On Apr 1, 2022, at 5:13 PM, Brent Hilpert via cctalk
> wrote:
>
> On 2022-Apr-01, at 11:51 AM, Paul Koning wrote:
>>> On Apr 1, 2022, at 2:38 PM, Brent Hilpert via cctalk
>>> wrote:
>>> On 2022-Apr-01, at 6:02 AM, Paul Koning via cctalk wrote:
>>>
When I looked at that ebay listing
On 2022-Apr-01, at 11:51 AM, Paul Koning wrote:
>> On Apr 1, 2022, at 2:38 PM, Brent Hilpert via cctalk
>> wrote:
>> On 2022-Apr-01, at 6:02 AM, Paul Koning via cctalk wrote:
>>
>>> When I looked at that ebay listing of "glass memory" it pointed me to
>>> another
> On Apr 1, 2022, at 3:38 PM, Joshua Rice wrote:
>
>
>
>> On Apr 1, 2022, at 7:51 PM, Paul Koning via cctalk
>> wrote:
>>
>> Neat looking stuff. It doesn't look like core rope memory in the sense of
>> the AGC ROM, nor in the sense of the Electrologica X1. It looks more like
>> the
> On Apr 1, 2022, at 7:51 PM, Paul Koning via cctalk
> wrote:
>
> Neat looking stuff. It doesn't look like core rope memory in the sense of
> the AGC ROM, nor in the sense of the Electrologica X1. It looks more like
> the transformer memory used in Wang calculators that you documented in
On 4/1/2022 11:51 AM, Paul Koning via cctalk wrote:
On Apr 1, 2022, at 2:38 PM, Brent Hilpert via cctalk
wrote:
On 2022-Apr-01, at 6:02 AM, Paul Koning via cctalk wrote:
When I looked at that ebay listing of "glass memory" it pointed me to another item,
> On Apr 1, 2022, at 2:38 PM, Brent Hilpert via cctalk
> wrote:
>
> On 2022-Apr-01, at 6:02 AM, Paul Koning via cctalk wrote:
>
>> When I looked at that ebay listing of "glass memory" it pointed me to
>> another item, https://www.ebay.com/itm/265623663142 -- described as "core
>> rope
On 2022-Apr-01, at 6:02 AM, Paul Koning via cctalk wrote:
> When I looked at that ebay listing of "glass memory" it pointed me to another
> item, https://www.ebay.com/itm/265623663142 -- described as "core rope
> memory". Obviously it isn't -- it's conventional core RAM. Interestingly
>
When I looked at that ebay listing of "glass memory" it pointed me to another
item, https://www.ebay.com/itm/265623663142 -- described as "core rope memory".
Obviously it isn't -- it's conventional core RAM. Interestingly enough, it
seems to be three-wire memory (no inhibit line that I can
> From: Steven Malikoff
> I have finally got around to scanning the print set for the DEC ME11-L
> memory expansion unit
Ah, thanks for that. The prints for the boards are available, in the
PDP-11/05 Engineering Drawings (on pp. 115-137), but the MF11-L backplane was
previously
I have finally got around to scanning the print set for the DEC ME11-L memory
expansion unit
and you can find it at
https://archive.org/details/dec-me-11-l-core-memory-system-engineering-drawings/
The quality is acceptable given that the office supplies shop where I (DIY)
scanned them on an A3
You can contact Joerg at his site http://retrocmp.com/contact For email see
the UNIBone - Get One Page
http://retrocmp.com/projects/unibone/283-unibone-getting-one
A fellow on the VCF DEC forum tried to contact Joerg about a UNIBone recently
and said he had better luck using the contact page
Hi, I have Joerg's Unibone bare boards available (and others listed at
https://retrobrewcomputers.org/doku.php?id=boardinventory#dec_digital_boards_designed_by_joerg_hoppe).
Feel free to contact me privately if interested.
Thanks,
Todd
On 1/10/2022 2:43 PM, Chris Zach via cctalk wrote:
Hm.
Hm. That is an idea. Technically I'm just wanting to get the thing
working to see if it works, so a Unibone would be reasonable. Now where
do I buy one/a kit/whatever.
C
On 1/10/2022 10:46 AM, Jay Logue via cctalk wrote:
On 1/9/2022 7:59 PM, Chris Zach via cctalk wrote:
*nod* I'll put
> From: Chris Zach
> I'm guessing that the DD11-F is significantly different from the DD11-B?
I assume theat "DD11-F" is a typo; there is, AFAIK, no DD11-F, and a Web
search revealeddidn't turn anything up. (There are DD11-CF and -CK
backplanes, as well as -DF and -DK, but the -CF and
On 1/9/2022 7:59 PM, Chris Zach via cctalk wrote:
*nod* I'll put the system aside again for awhile. But if I come across
a DD11-C or D I'll go back to work on it.
I understand your frustration, as I've spent the better part of a year
acquiring and fixing an ME11-L and associated board sets
Sigh, shouldn't try to type when I'm this tired. Female 9-pin (to plug into
the BA11-D) to male 15-pin (for the DD11-C/D to plug into).
*nod* I'll put the system aside again for awhile. But if I come across a
DD11-C or D I'll go back to work on it.
In the "Go to Unibus hell" category I DO
> an adapter cable to go from a 9-pin male (shell; female pins) to a
> 15-pin female (shell; male pins)
Sigh, shouldn't try to type when I'm this tired. Female 9-pin (to plug into
the BA11-D) to male 15-pin (for the DD11-C/D to plug into).
Noel
> From: Chris Zach
> the DD11-B is a MUD backplane
No, it's SPC; other sources, e.g.
http://www.chdickman.com/pdp11/Notes/DD11.shtml
agree.
So if you have a DD11-B, you must have a BA11-D, with the 9-pin power
plugs.
The best thing to do is get a DD11-C or -D, and build an adapter
On 1/9/22 4:04 PM, Chris Zach via cctalk wrote:
I'm working on my pdp11/10 getting it back together. One
problem I think I have is that the secondary memory (a
Plessy 700101-100) may be shorting the -15 line for some
reason. Working on it, but does anyone have a manual or
anything like that
Hm. So the DD11-B backplane does not appear to be SPC/MUD. Instead it
seems to handle 4 SPC devices along with a DF11 "communication line
adapter" in the middle AB slots.
Oi.
That brings up an interesting question: How did this system ever work in
the first place? I know I ran it with two of
If you have a 10-1/2" box, you can mount a MUD backplane - but you might
still have an issue because the older BA11-D boxes use the old 9-pin power
connectors, and the MUD backplanes (DD11-C, -D, etc) all use the newer 15-pin
ones.
There we go. I have an 11/05 in a BA11-D box with a DD11-B
> From: Chris Zach
> the secondary memory (a Plessy 700101-100) may be shorting the -15 line
> for some reason. Working on it, but does anyone have a manual or
> anything like that for this kind of memory board?
I've got a Plessey core memory manual somewhere, but
Worst case I guess I could put a broken MS11-PL board in and set it for
16k start. It's got bad memory chips on it but I think the first 16k
were good. And as a bonus it can work in both a +15 *AND* a +12 volt
Unibus (yeah, the 11/24 used +12 on the +15 lines. No idea what was
wrong with DEC)
I'm sorry, on the memories, I went to look at my old notebook form that
era, but it seems some pages have fallen out over time :-)
I think a friend has an 11/05 or 10, I will ask him for its
configuration and see if that will help.
cheers,
Nigel
Nigel Johnson, MSc., MIEEE, MCSE
Probably. It's a 1973 version, the DD11-B is a MUD backplane, but it
seems to only have power plugs for +5,+15,-15. Looking at the MUD specs
I see there are backplane pins assigned for +20 and -5 so I might be
able to cobble something together.
That's one of the fun things about Unibus: There
I would assume that your 11/10 has the suffix -NC. There were two
versions, the -NC used -15V four wire memory, and the later -SC used
+20V three-wire memory.
The +20V was provided by a MUD slot (Modified Unibus Device) and there
was usually a big red sticker in it warning to not plug a
I'm working on my pdp11/10 getting it back together. One problem I think
I have is that the secondary memory (a Plessy 700101-100) may be
shorting the -15 line for some reason. Working on it, but does anyone
have a manual or anything like that for this kind of memory board?
Alternately, what
On Fri, Oct 23, 2020 at 11:57 AM Eric Smith wrote:
> On Wed, Oct 21, 2020 at 6:22 AM Pontus Pihlgren via cctalk <
> cctalk@classiccmp.org> wrote:
>
I have seen PDP-15 core memory and it is not that format. It looks like
>>
> the memory modules from a PDP-8/I or -8/
rd?
> >
>
> I have seen PDP-15 core memory and it is not that format. It looks like
> the memory modules from a PDP-8/I or -8/L
>
The ME15 memory for the PDP-15 used that kind of memory, but it normally
used an 18-bit H215. I think there was another variant that offered parity
th
> (Whether that's all done on the companion driver boards, and the H21x
> card would just bring the wiring of the two banks out to the edge
> connector in parallel, letting the driver board do what it wants, I
> don't know - you'd have to look at the MM11-L engineering
> From: Chris Zach
> My guess is the H215 has two more core fields on it
I uploaded a (crappy - sigh) image of an H215 I have to here:
https://gunkies.org/wiki/File:H215-core-memory-board.jpg
and it's clearly not symmetrical, but does have a slightly bugger blank space
than
to take a picture of it?
C
On 10/21/2020 1:33 PM, Richard Sheppard via cctalk wrote:
There’s a piece of core on eBay
https://www.ebay.com/itm/DEC-Digital-H214-Digital-Equipment-Core-Memory-Litton-38540-1/111384040291
which claims to be H214. The interesting thing is the label says 8K x 16
eppard via cctalk wrote:
> > > > There’s a piece of core on eBay
> > > > https://www.ebay.com/itm/DEC-Digital-H214-Digital-Equipment-Core-Memory-Litton-38540-1/111384040291
> > > > which claims to be H214. The interesting thing is the label says 8K x
> > > > 16 but the silkscreen says 8K x 19.
> > > >
> > > > Sent from Mail for Windows 10
> > > >
://www.ebay.com/itm/DEC-Digital-H214-Digital-Equipment-Core-Memory-Litton-38540-1/111384040291
which claims to be H214. The interesting thing is the label says 8K x 16 but
the silkscreen says 8K x 19.
Sent from Mail for Windows 10
gt; un-woven. Want me to take a picture of it?
>
> C
>
> On 10/21/2020 1:33 PM, Richard Sheppard via cctalk wrote:
> > There’s a piece of core on eBay
> > https://www.ebay.com/itm/DEC-Digital-H214-Digital-Equipment-Core-Memory-Litton-38540-1/111384040291
> > which clai
My guess is the H215 has two more core fields on it since mine has 3 (18
bits plus parity). Odd they could fit up to 20 bits, maybe an early ECC
(16b+4 ECC?)
C
On 10/21/2020 7:17 PM, Noel Chiappa via cctalk wrote:
> From: Richard Sheppard
> There's a piece of core on eBay .. which
I'm pretty sure the H216 was too new to have been used in an MA10 or
MB10, but I don't know which core planes or other modules were used.
They might have still been using core modules made by external vendors
like Ferroxcube.
It's looking to be the same vintage as the 11/05 memory I have (the
3. Tell us more about Doug, and his apartment :-)
Alas, those legends are lost in the mists and tubes of time... Only
fragments remain to cause giggles at random intervals.
CZ
> From: Richard Sheppard
> There's a piece of core on eBay .. which claims to be H214. The
interesting
> thing is the label says 8K x 16 but the silkscreen says 8K x 19.
DEC did that a lot; used one silkscreen (and etch) for two different modules,
with differing componet sets to
Very similar to mine, however this one has only one of the core mats
un-woven. Want me to take a picture of it?
C
On 10/21/2020 1:33 PM, Richard Sheppard via cctalk wrote:
There’s a piece of core on eBay
https://www.ebay.com/itm/DEC-Digital-H214-Digital-Equipment-Core-Memory-Litton-38540-1
There’s a piece of core on eBay
https://www.ebay.com/itm/DEC-Digital-H214-Digital-Equipment-Core-Memory-Litton-38540-1/111384040291
which claims to be H214. The interesting thing is the label says 8K x 16 but
the silkscreen says 8K x 19.
Sent from Mail for Windows 10
On Tue, Oct 20, 2020 at 11:26:22PM -0400, Chris Zach via cctalk wrote:
> > Or maybe a PDP-15? 18 bits plus parity.
>
> Possible, did the pdp15 use that type of board?
>
I have seen PDP-15 core memory and it is not that format. It looks like
the memory modules from a
Doug Jackson wrote:
> Those of us late to the party may like to know:
> 1. What was AL
> 2. Why was it famous?
Not AL, but AI. Also known as MIT-AI on the ARPANET. It was the PDP-10
used by the MIT AI lab, hence the name. The Incompatible Timesharing
System was developed on their PDP-6, later
Those of us late to the party may like to know:
1. What was AL
2. Why was it famous?
3. Tell us more about Doug, and his apartment :-)
Kindest regards,
Doug Jackson
em: d...@doughq.com
ph: 0414 986878
Check out my awesome clocks at www.dougswordclocks.com
Follow my amateur radio adventures
Chris Zach wrote:
> Did AI use MA10 memory boxes?
No. It had the original 256K "moby" from Fabri-Tek, and another 256K
from Ampex. The associated PDP-6 had an older DEC Type 16x-something
16K memory.
> Did any of that stuff survive?
Maybe bits and pieces here and there. The AI KA10 went to
On Tue, Oct 20, 2020 at 10:02 PM Chris Zach wrote:
> Ok, so the MF10 would have been hooked up to a KI10.
>
The ME10 was the first core box for the PDP-10 memory bus that supported
22-bit addressing, and could be used on the KA10, KI10, or KL10 (with a
DMA20 memory bus interface, not available
@classiccmp.org>> wrote:
The real weird one is a quad board H216. I thought it was a Unibus core
memory board,
Most of the DEC core plane boards were not specific to any particular
bus. though there are some exceptions.
but it's 8k*19 bits, which means it came from one
On Tue, Oct 20, 2020 at 8:06 PM Chris Zach via cctalk
wrote:
> The real weird one is a quad board H216. I thought it was a Unibus core
> memory board,
Most of the DEC core plane boards were not specific to any particular bus.
though there are some exceptions.
> but it's 8k*19 bi
Or maybe a PDP-15? 18 bits plus parity.
Possible, did the pdp15 use that type of board?
I would guess that that would be much more likely.
Problem is I have never been near a pdp15, but I have been in proximity
to AI. I don't remember what happened to it after Doug's apartment, I do
On 10/20/2020 9:05 PM, Chris Zach via cctalk wrote:
> Now I'm starting to look through boxes to see if I have another 11/24
> CPU. I seem to recall picking a second one up somewhere, I also want to
> see if I still have the driver board for the second Plessy core memory.
> Might be a
Now I'm starting to look through boxes to see if I have another 11/24
CPU. I seem to recall picking a second one up somewhere, I also want to
see if I still have the driver board for the second Plessy core memory.
Might be around, might have been pitched.
So far I did find a box of DZ11's
The following Ebay listing seems nice:
https://www.ebay.com/itm/252576335317
It shows the advance in technology from core to transistor to SRAM wafer.
On Tue, Jul 21, 2020 at 11:52 PM Gary Sparkes via cctalk <
cctalk@classiccmp.org> wrote:
> I was looking for confirmed broken, not just "this
I was looking for confirmed broken, not just "this is from X system
untested" - I have a real aversion to wasting potentially usable hardware
for restorations myself.
I might recommend the russian UAV ones that seem to be up on ebay if
there's nothing else around
On Tue, Jul 21, 2020 at 10:05 AM
At 04:35 AM 7/21/2020, Gary Sparkes via cctalk wrote:
>Anyone? even if it's physically broken
You don't like the ones on eBay?
- John
Anyone? even if it's physically broken
-- Forwarded message -
From: Gary Sparkes
Date: Fri, Jul 10, 2020 at 7:00 PM
Subject: Looking for BAD / Faulty core memory for a display piece
To: General Discussion: On-Topic and Off-Topic Posts
Unrepairable preferred
It'll be going
Unrepairable preferred
It'll be going into an epoxy resin setup that someone I know is doing for a
table, and I really want to get something that still LOOKS OK but is...
well, just faulty and won't be restorable to service so we don't destroy
any potentially usable hardware.
Ideas/suggestions
On Thu, Apr 16, 2020 at 6:02 PM Jules Richardson via cctalk <
cctalk@classiccmp.org> wrote:
> On 4/15/20 6:22 PM, keith--- via cctalk wrote:
> > I have three others with the cover still on :) I want to make a clear
> > plexiglass cover for them.
>
> Just for fun, this is what I have from a
On 4/15/20 6:22 PM, keith--- via cctalk wrote:
I have three others with the cover still on :) I want to make a clear
plexiglass cover for them.
Just for fun, this is what I have from a Lockheed MAC-16 machine:
http://www.classiccmp.org/acornia/tmp/catcore.jpg
... the white line is a cat
than "Re: Contents of cctech digest..."
Today's Topics:
1. Re: Core Memory Photo (ke...@saracom.com)
2. Re: Core Memory Photo (Fred Cisin)
3. Re: Core Memory Photo (Joshua Rice)
--
Message: 1
Date: Mon, 13 Apr 202
he lab. Ouch. Someone had
>> asked for a picture of core memory without the cover so I thought it
>> would do.
>
> It is beautiful!
>
>
>
On Mon, 13 Apr 2020, keith--- via cctalk wrote:
"Ouch. Looks like that core took a serious hit."
Yep it did. We ran the microscope into it at the lab. Ouch. Someone had
asked for a picture of core memory without the cover so I thought it
would do.
It is beautiful!
"Ouch. Looks like that core took a serious hit."
Yep it did. We ran the microscope into it at the lab. Ouch. Someone had
asked for a picture of core memory without the cover so I thought it
would do.
Ouch. Looks like that core took a serious hit.
On 4/12/2020 4:37 PM, keith--- via cctalk wrote:
Here is a link to pictures of core memory from a PDP1145.
https://devilanse.wordpress.com/2009/11/03/nablopomo-digital-equipment-corporation-pdp-1145/
Here is a link to pictures of core memory from a PDP1145.
https://devilanse.wordpress.com/2009/11/03/nablopomo-digital-equipment-corporation-pdp-1145/
Not that I expect anyone to have a need for it, but just for the heck of it :
here are a few datasheets for single cores ( From a Philips Databook 1973 )
ftp://ftp.dreesen.ch/Cores/CoreMemory_core_datasheet.pdf
Enjoy..
Jos
On Fri, Apr 19, 2019 at 5:46 AM Noel Chiappa via cctalk <
cctalk@classiccmp.org> wrote:
> where the description of the invention of 3-wire core can be found on pg.
> 231; it was invented by a group of engineers, based on a similar idea used
> in
> Stretch. There is indeed a patent, No. 3,381,282,
light of something pretty to look
at. As well as an educational glimpse into explaining some history.
Good luck!
Sent from my Apple /c
> On Apr 17, 2019, at 11:30 PM, Andrew Luke Nesbit via cctalk
> wrote:
> I have been wanting to acquire a plane of magnetic core memory as
> On Apr 18, 2019, at 11:18 PM, dwight via cctalk wrote:
>
> Although, after written, there is little magnetism lost out side of the ring,
> while being magnetized, there is quite a bit of stray magnetism. By placing
> the the rings at 90 degrees, it minimizes the magnetism induced in the
>
> On Apr 18, 2019, at 9:01 PM, Anders Nelson wrote:
>
> I believe I read they weaved the planes this way to minimize crosstalk, EMI
> or heat.
>
> =]
The zigzag routing, you mean? Yes, that's to minimize crosstalk. It's nicely
described in a training manual for the Electrologica X1.
> From: Curious Marc
> I believe 3 wire memory was first introduced by IBM in their 360
> systems ... They would almost certainly have patented their way to do it
Correct (and your knowledge and memory is good)! Motivated by this clue, I
looked in:
Emerson W. Pugh,
, "cctalk@classiccmp.org"
Date: Thursday, April 18, 2019 at 7:08 PM
To: Noel Chiappa , ,
"cctalk@classiccmp.org"
Subject: Re: Plane of core memory
On 04/18/2019 03:15 PM, Noel Chiappa via cctalk wrote:
> From: Jon Elson
> As soon as somebod
From: cctalk on behalf of Anders Nelson via
cctalk
Sent: Thursday, April 18, 2019 6:01 PM
To: paulkon...@comcast.net; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Plane of core memory
I believe I read they weaved the planes this way to minimize crosstalk, EMI
or heat
tudent when he invented
coincident-current core memory.
Jon
t; with conventional inhibit, keeping sense separate avoids the overhead of
> switching the signal path between two very different bits of circuitry.
>
> Compared to many other core memory designs of that same era, the 6000
> memory is quite fast, with access times of a few hundred nanosec
>Stewart-Warner (I think) vector graphics terminals
> from the 1960s. Check Ebay in a week or three...
Correction: Hazeltine.
--
Will
> -Original Message-
> From: cctalk On Behalf Of Chuck Guzis via
> cctalk
> Sent: 18 April 2019 17:30
> To: Jim Manley via cctalk
> Subject: Re: Plane of core memory
>
> On 4/18/19 9:02 AM, Jim Manley via cctalk wrote:
> > Jussi Kilpelainen'
> From: Jon Elson
> As soon as somebody figured out that you could combine the sense and
> inhibit wires, everybody immediately went to 3-wire planes.
I"m suprised the idea wasn't patented. Or maybe it was, and they made the
license widely available at modest terms?
Noel
On 2019-Apr-18, at 9:30 AM, Chuck Guzis via cctalk wrote:
> On 4/18/19 9:02 AM, Jim Manley via cctalk wrote:
>> Jussi Kilpelainen's page cited above (
>> https://www.tindie.com/products/kilpelaj/core-memory-shield-for-arduino/)
>> refers to the work of Ben North and Oliver N
On 2019-Apr-18, at 8:47 AM, Jon Elson wrote:
> On 04/18/2019 04:49 AM, Brent Hilpert via cctalk wrote:
>> It's a 4-wire 3D planar array. By topology and construction I would guess it
>> date it from the 60s.
> Make that EARLY '60s. As soon as somebody figured out that you could combine
> the
the above, might there be a way to extend the passive
> read to be a worthy "exhibit" I could take to shows? Core memory is
> impressive just to look at, but reading it out using the PC and
> displaying the contents is so easy to fake that I think people will
&g
On 4/18/19 10:33 AM, dwight via cctalk wrote:
> I don't believe there is a simple non-destructive way to read the state.
https://patents.google.com/patent/US3924248
the levels used, the entire array can be read.
Dwight
From: cctalk on behalf of Jim Brain via cctalk
Sent: Thursday, April 18, 2019 10:19 AM
To: cctalk@classiccmp.org
Subject: Re: Plane of core memory
I am the enviable owners of a plane of memory (procured a few
> Or still do a fluid one, but take Turing's suggestion
> and use gin as the medium.
Better use some good error correction.
--
Will
> (Sorry, not currently interested in selling :-)
Well, I am. And I have a LOT of 8K core system modules (planes and
drivers) from old Stewart-Warner (I think) vector graphics terminals
from the 1960s. Check Ebay in a week or three...
--
Will
> I don't expect that any EBAM has survived--I think all of the stuff I
> saw at CDC ADL was scrapped. Seems that the technology is all but
> forgotten today:
>
> https://bit.ly/2KOOl82
How was the CDC EBAM different from the other memory tubes, like the Radechon?
--
Will
My mention of electron-beam memory devices left off GE's BEAMOS and
RCA's Selectron.
WikiPedia has a nice article on the Selectron, but BEAMOS took a bit of
looking:
http://rcaselectron.com/GEBEAMOS.html
Too bad that neither RCA nor GE were in the computer business in 1978.
--Chuck
On Thu, 4/18/19, dwight via cctalk wrote:
> My understanding was that the mercury delay lines
> needed periodic repairs ( not sure what the cause
> was but mercury does dissolve into many metals ).
> If I were going to make a delay line memory, I'd go with
> the magnetostrictive. These are
conventional inhibit, keeping sense separate avoids the overhead of switching
the signal path between two very different bits of circuitry.
Compared to many other core memory designs of that same era, the 6000 memory is
quite fast, with access times of a few hundred nanoseconds and full cycle (re
On 4/18/19 9:42 AM, Al Kossow via cctalk wrote:
>
> The 1401 guys at CHM were working on one using a real 701 tube.
> I don't think it was ever finished.
I don't expect that any EBAM has survived--I think all of the stuff I
saw at CDC ADL was scrapped. Seems that the technology is all but
On 4/18/19 2:08 AM, Andrew Luke Nesbit wrote:
This is great and I will look into this.
I'm generally not into SBCs. (I do more with virtualization than have
SBCs proliferate.) But the idea of having core memory, and it working,
is quite appealing to me.
But my original request
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