10 Jul
2009
10 Jul
'09
12:38 p.m.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180376993048
On the chance that the buyer reads this list, it is the call store buffer
ferrite sheet memory from a 1ESS switch.
Picture on page 2380 of the Bell System Technical Journal, Sep 1964 part 2.
10 Jul
10 Jul
2:21 p.m.
New subject: DEC H207 Core Memory Boards
Hello, all,
I recently came into possession of four DEC H207 Core Memory boards.
They consist of a quad-width board that has a large number of signal
steering diodes, with an attached daughter board that has a 4K x 16
"Planar Memory" array made by Electronic Memories. The boards all have
original DEC warranty seals on them, dated June of 1971.
I'm curious as to what DEC machine may have used these boards, and what
support Flip Chip modules (X & Y drive, Sense/Inhibit, and addressing
logic) may have been used with the core stacks to provide a 4Kx16 memory
subsystem.
Give the 16-bit array size, I assume that it may have been used in a
PDP-11, but I suppose (with four wasted bits) it could have been used in
some form of PDP-8 system.
Any help greatly appreciated.
Rick Bensene
The Old Calculator Museum
http://oldcalculatormuseum.com
2:19 p.m.
New subject: DEC H207 Core Memory Boards
This is so basic I have to ask why you took the time to write all that up
rather than hitting Google. :-)
H207 U 4096x16 core stack for 11/15 (on G616 & G617)
Zane
On Fri, 10 Jul 2009, Rick Bensene wrote:
Hello, all,
I recently came into possession of four DEC H207 Core Memory boards.
They consist of a quad-width board that has a large number of signal
steering diodes, with an attached daughter board that has a 4K x 16
"Planar Memory" array made by Electronic Memories. The boards all have
original DEC warranty seals on them, dated June of 1971.
I'm curious as to what DEC machine may have used these boards, and what
support Flip Chip modules (X & Y drive, Sense/Inhibit, and addressing
logic) may have been used with the core stacks to provide a 4Kx16 memory
subsystem.
Give the 16-bit array size, I assume that it may have been used in a
PDP-11, but I suppose (with four wasted bits) it could have been used in
some form of PDP-8 system.
Any help greatly appreciated.
Rick Bensene
The Old Calculator Museum
http://oldcalculatormuseum.com
2:33 p.m.
New subject: DEC H207 Core Memory Boards
On 7/10/09, Rick Bensene <rickb at bensene.com> wrote:
Hello, all,
I recently came into possession of four DEC H207 Core Memory boards.
They consist of a quad-width board that has a large number of signal
steering diodes, with an attached daughter board that has a 4K x 16
"Planar Memory" array made by Electronic Memories. The boards all have
original DEC warranty seals on them, dated June of 1971.
I'm curious as to what DEC machine may have used these boards, and what
support Flip Chip modules (X & Y drive, Sense/Inhibit, and addressing
logic) may have been used with the core stacks to provide a 4Kx16 memory
subsystem.
They sound like the right size and date for an 11/20. I have a few
(since I have the rescued bits of a cut-up 11/20) and can check what
you have against what I have. Can you send me a picture off-list?
I'll compare it with what I have, and I can confirm handle numbers for
the sense/inhibit and XY boards (they should be on a master module
list anyway - they were common in 1971).
Unfortunately for me, I wasn't the only one from that company who got
some parts. I think I didn't manage to retrieve 100% of the core that
was in the three-cabinet 11/20. I am missing at least one core stack
that I know of. I was planning on a modern memory replacement if I
ever get this machine put back together (it was stripped and the PSUs
recycled before it hit the dumpster, and I saved the carcass and as
many boards as I could). My ultimate goal for this is to run first
RT-11 to check it out, then the early version of UNIX that was
recently demonstrated on simh (I still need to come up with an RF-11
emulator; I think I have most of the rest of the hardware that's
required).
Give the 16-bit array size, I assume that it may have
been used in a
PDP-11, but I suppose (with four wasted bits) it could have been used in
some form of PDP-8 system.
Probably not. There are 4Kx12 planes for the PDP-8 (I don't know the
number off the top of my head) and it's not the same as what was used
in the PDP-11. Cores cost too much to "waste" 25% of them.
-ethan
3:02 p.m.
New subject: DEC H207 Core Memory Boards
Ethan Dicks wrote:
On 7/10/09, Rick Bensene <rickb at bensene.com> wrote:
While the use of the H207 has apparently been determined, out of curiousity was
there ever any ECC core memory for the PDP-8?, it might have have had a width
of 16 or 17 bits.
Give the 16-bit array size, I assume that it may
have been used in a
PDP-11, but I suppose (with four wasted bits) it could have been used in
some form of PDP-8 system.
Probably not. There are 4Kx12 planes for the PDP-8 (I don't know the
number off the top of my head) and it's not the same as what was used
in the PDP-11. Cores cost too much to "waste" 25% of them.
4:43 p.m.
New subject: DEC H207 Core Memory Boards
On 7/10/09, Brent Hilpert <hilpert at cs.ubc.ca> wrote:
While the use of the H207 has apparently been
determined, out of curiousity was
there ever any ECC core memory for the PDP-8?, it might have have had a width
of 16 or 17 bits.
I have never seen ECC core for any DEC machine (but don't take that as
the definitive answer). The PDP-8/L, though, was commonly shipped
with parity (there's space in the CPU chassis that's pre-wired for the
parity support cards and the slots for the core sense/inhibit wires
are wired for 13 bits). It might also be supported in the -8/i, but
I'd have to look that up (I know about the -8/L for certain because
one of mine arrived with that option populated).
-ethan
5644
days inactive
5644
days old
5 comments
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participants (5)
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aek＠bitsavers.org -
ethan.dicks＠gmail.com -
healyzh＠aracnet.com -
hilpert＠cs.ubc.ca -
rickb＠bensene.com