On Thursday, May 06, 1999 9:43 PM, allisonp(a)world.std.com
[SMTP:allisonp@world.std.com] wrote:
> They are roughly 50mils x 11 mils x 15mils. Cross section of the
> doughnut is rectangular at 15x11 mils. The reason for such rough
> measurements is my vernier is only good to .001" and I'd need
> somthing fancier to be more accurate. By eyeball the 8e cores are
> smaller!
According to Pugh's "IBM's 360 and Early 370 Computers", in 1963 IBM was
manufacturing both 30x50 mil and 19x32 mil cores (inside diameter x outside
diameter). Allison's measurements match up with the larger size.
According to the book, the IBM 7080 and 7094 used the smaller size. Thus,
these cores were probably intended for either the 1401, or the 7090 if any of
these were still in production in 1963.
Does anyone out there have a 1401, or a 1401 core stack?
Something I hadn't read of before: the 7090's core planes were immersed in oil
to help with heat dissipation. I wonder whether there was a sticker on the
machine (right underneath "Trained Service Personel Only"): "Change oil every
six months or 100,000 punched cards".
Another interesting point: The defect ratio of cores that reached the plane
wiring stage was 1 out of 8,000. This sounds incredibly high, but IBM's core
manufacturing facilities were state of the art. Imagine the difference between
the process control used then, and current integrated circuit fabrication
techniques!
> A simple core frame would be 8x8 (64 bits) and use a 4 wire system as
> that simplifies the select, inhibit and sense hardware. I'd likely go
> with late 70s level TTL and transistors to drive these and to sense the
> outputs I don't know if I'll use transistors (1968 or earlier designs)
> or
> comparator chips (aka 1540, 710, 711) will be used. They would also be
> consistant with 1970s technology.
I'd very much like to see your schematics, once you're happy with them. Better
late than never to learn about appropriate circuit designs.
----
John Dykstra jdykstra(a)nortelnetworks.com
Principal Software Architect voice: ESN 454-1604
Enterprise Solutions fax: ESN 667-8549
I don't know how 'classic' this one is just yet, but...
I came across a partly gutted HP700IL at my local used place yesterday. It
was missing its power supply, but still had the CPU card. I took a look,
and it looks like the heat sink was actually bolted to the CPU chip (a la
the DEC Alphas).
Is the unit worth grabbing? It looked kind of slick. How hard would it be
to find a power module?
Thanks...
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner and head honcho, Blue Feather Technologies
http://www.bluefeathertech.com
Amateur Radio:(WD6EOS) E-mail: kyrrin(a)bluefeathertech.com
SysOp: The Dragon's Cave (Fido 1:343/272, 253-639-9905)
"Our science can only describe an object, event, or living thing in our own
human terms. It cannot, in any way, define any of them..."
At 06:48 PM 5/6/99 -0500, you wrote:
>Where are you located and how much are they?
They're in Orlando Florida. He has six of them and I expect he'll take
$100 each plus shipping. Call Don at (407) 260-9109.
Don is the same guy that has the rack mount PCs. I've written up a bit
about them and posted it at "www.intellistar.net/~rigdonj/don-ad.htm".
That a look if you're interested. The boxs for the Apples are not the same
as the one for the PCs. I expect he'll take $125 for one of them with a
single CPU card (486-100), 4Mb Ram, a VGA video card, a 520 Mb hard drive
and a floppy drive. He has a lot of neat data acquision and control cards
for them and some of the cases have dual computers in them.
BTW the Apples have a keylock on the front to turn them off and on with.
Don doesn't have the keys. I popped the switch portion off of the lock on
one of them and turned the switch shaft with a pair of pliars. If you got
one, you can do the same or replace the lock/switch or have a key made.
Joe
>
>George
>
>> I found some strange looking rack mount boxs in a salvage place today.
>> They're marked AuudioVision 90. I opened one up and found that it has an
>> Apple Mac Quadra 950 built into it. I rounded up a monitor (but no
>> keyboard) and fired one up. It boots to MacOS then asks for a password.
>> Is there anyway to get around the password other than reinstalling
>> everything?
>> There are six of them available. Is anyone interested in them? They have
>> a
>> huge non-apple power supply, and at least one floppy and one hard drive
>> and all the regular Nu-Bus (?) slots. Another that I opened had two hard
>> drives.
>>
>> Joe
>>
>
>
>
--- Marvin <marvin(a)rain.org> wrote:
>
> As it is really getting close now, just curious how many people on this list
> will be at Dayton Hamvention.
I'm hoping to go (I live in Columbus), but I also have another thing going
on at the same time in Western PA (near Butler). :-(
If I can go, I'd be very interested in a get-together.
-ethan
_________________________________________________________
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Greetings,
I've managed to transfer the contents of CURSOR Magazine (for the PET)
cassettes #1 to #8 to my Amiga.
Cassette #2 is incomplete due to damage to one program. Is there already an
archive of Cursor Magazine cassettes? Does anyone have the program "RACE"
>from Cursor #2?
--
Doug Spence
ds_spenc(a)alcor.concordia.ca
http://alcor.concordia.ca/~ds_spenc/
John said:
> Does you have a reference on how to build an oscillator or counter out
> of neon lamps?
Here is the zip file that put up a couple of months ago.
It contains 22 scanned pages of glow lamp logic circuits.
The zip file is 1.6 MB.
http://www.best.com/~dcoward/LAMP.ZIP
I hope this helps,
--Doug
====================================================
Doug Coward dcoward(a)pressstart.com (work)
Sr. Software Eng. mranalog(a)home.com (home)
Press Start Inc. http://www.pressstart.com
Sunnyvale,CA
====================================================
Mike wrote:
>> Perhaps a
>> smaller array, but with LARGE cores where the magnetic state could have
>> some visual indicators.
>How would that work? Would you have an LED for each bit or something?
Get a little bit away from magnetic storage, and you can use neon
lamps as storage elements which are self-illuminating :-).
Neon lamps - when powered by DC - have a nice memory property: They
take about 90VDC to light up, but after they light up they'll stay on
until the voltage drops below 60VDC or so. Only problems are:
1. The thresholds can vary greatly from unit to unit.
2. The thresholds will vary depending on ambient light, as well.
Property 2 above can be used to build oscillators out of pairs
of neons, as a matter of fact...
Tim.
At 10:25 PM 5/5/99 -0700, Sellam Ismail wrote:
>
>Yeah, then I spray-painted it neon pink because I didn't
like the original
>color. Core memory is cool.
No way. It wouldn't be Art until you made it into a dress,
as a
commentary on the way technology has shaped our lives.
- John
This is too much like what actually happened to me.
A few years ago I learned that someone had an IMSAI
8080 they wanted to get rid of, in a city 150 miles
>from where I live.
I was willing to make the trip to go and rescue it.
But when I finally got in touch with the owner by phone,
they said "I wish you had gotten ahold of us sooner!
We just gave it to an artist who wanted to use it
for a collage."
I can still imagine that front panel plastered in
bright-colored goo, along with a bunch of other
techno-junk, hanging on some wall in humiliation!
--- Mark Metzler
VON NEUMANN MACHINES
Online Computer History Bookstore/Museum
http://home.pacbell.net/mmetzler/vnm.html
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>r. said:
>On Fri, 30 Apr 1999, Huw Davies wrote:
>The NeXTs don't even really have power switches.
Command-command-~ is supposed to bring up a monitor through a non-maskable
interrupt, into which you can enter the command ? for info on available
commands. "halt" saves files to disk and gracefully halts the system. "mon"
goes to the ROM monitor but does not gracefully halt the system.
An emergency shutdown is available by pressing <left alternate>-<left
command>-<numeric keypad *>. (on an ADB keyboard, use the command bar
instead of the left command key). This will not power off the computer but
will do a hard reset of the CPU. This does *not* result in a clean
shutdown, and can damage an optical disk if it's in the middle of a write
operation (so I hope you didn't just do it ;-) ).
- Mark
