My understanding is that DZU made disk storage subsystems including both drives and
control units and that many if not all into the 1980s were copies of IBM disk storage
products.
The recollection is that IBM 2314 era SCU used a form of TROS where words were strips of
film that punched a hole a one or a zero at each transformer (core) location to route the
current around or through a core. The 2841 may have had the same technology. This could
be done relatively easily in the field.
At Memorex they used wire rope as TROS for the same function as I think did other PCMs.
This was smaller and allowed faster clocks than film strips but was difficult but not
impossible to field upgrade. Next generation SCUs went to writable control store's
loadable from FDD's.
So this might be a 2314 era TROS so its date could be early 70s given first PCM 2314's
SCUs didn't ship until the early 1970s so I have a hard time thinking the Russian
system beat US capitalism :-)
But if they copied the 2841 and it used TROS then it could be late 60s
Tom
-----Original Message-----
From: Tony Aiuto [mailto:tony.aiuto at
gmail.com]
Sent: Saturday, December 02, 2017 8:45 AM
To: Brent Hilpert; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Can anyone identify what this board is/does?
On Fri, Dec 1, 2017 at 11:05 PM, Brent Hilpert via cctalk < cctalk at
classiccmp.org> wrote:
On 2017-Dec-01, at 7:12 AM, Tony Aiuto via cctalk
wrote:
https://www.ebay.com/itm/263005049078
EBay listing for a "Soviet Magnetic Ferrite Core Memory Board". It
looks like 20 something gigantic cores and a lot of diodes. I am
guessing it is some kind of ROM, but it doesn't look like a rope
memory. And maybe the cores are not cores at all, but some sort of
inductor. I've not seen this before.
That's very funny.
It looks to be a core rope memory that hasn't been programmed.
I think that is the most likely case.
Other organisations might be possible, but it looks like a
pulse-transformer type of core-rope, where the cores are just for
ordinary induction, not switching/memory cores.
- the matrix of black what-look-to-be diodes would be
data-wire isolation diodes
- the little brown 'stools' are wire routing posts
- you can see the mulit-turn sense windings (bluish) already
present on the cores
- above the cores are the sense amplifiers or 1st stage
thereof
- there is one wire through all the cores, perhaps a test wire
for core and sense amp response
Each data-wire would start at one of the solder pins in the pin matrix
on the left, weave through the cores to encode the data, turn back
180, then 90 degrees around one of the stools to drop down and
terminate at the solder pin by an isolation diode.
There would be another board for decoding the address to 1-of-x and 1-of-y.
I didn't count precisely but it looks like it would be 256 words of 20
bits.
That might be a date code of 6847 on a cap (or is it 6B47?), so
perhaps earlier than the listing-stated 1981.
Actually, it kind of hints at it in the description: "With out
Firmware ROM wire (empty slots)"
Ah, you read the description. I just looked at the title and saw "with the
firmware". My addled brain made the leap to a external firmware, which made no sense.
"firmware ROM wire" would be a clear case for rope memory.
On Fri, Dec 1, 2017 at 11:32 PM, Charles Anthony <charles.unix.pro at
gmail.com
wrote:
The last picture has "???-5". Some googling takes us to
https://bg.wikipedia.org/wiki/%D0%94%D0%97%D0%A3
"DZU is a factory in Stara Zagora , a major producer of magnetic disk
storage devices (hard drives and floppy disks) during the rise of
computer production in Bulgaria in the 1970s and 1980s, century. Today
it is part of VIDEOTON Holding ZRt., Hungary [1] ."
The article says it was a disk drive factory, but maybe...
-- Charles
Given the cleanliness of the board and other things the seller is offering, my guess now
is that this NOS from the DZU plant.
Thanks, everyone.