🚀 go-pugleaf

In article <6536@tekgen.BV.TEK.COM> ralphc@tekcae.CAX.TEK.COM (Ralph Carpenter) writes:
>
>An interesting reminder of my youth hangs on the wall of my
>cubicle:  a 26" platter from a CDC 6600 disk drive that was
>decommissoned about 1973.  I think the unit was a Bryan(t).  As I
>remember, the heads were hydraulically driven.  The story was
>that one job would periodically show up that put the mini-van
>sized unit into resonance and, unless the operator rolled that
>job out until some other jobs came along to randomize the head
>movement, the whole unit would hop until it moved off the holes
>in the raised floor.
>

You are right.  It was from a Bryant disk, otherwise known as the
6603 disk.  CDC did make a drive that had even larger platters
approximately 3'-4' in diameter.  The University of Illinios use
to have one on there G20 system.  I remember rolling the platter around
in the hallways of the EE building.  They also made nice coffee tables.
One such table use to be at FermiLab.

Anyway, back to the Bryant:

	Capacity:	56Mbyte
	Weight:		4,300 lbs
	Surfaces:	32 (4*9 - 4)

The unit had 4 quadrants.  The quadrants were organized into a upper
half and a lower half.  Each half used equal and oppsite positioning
to conteract arm movement.

The first unit was delivered to Livermore.

My friend Don Crouse who installed a good many of these drives has quite
a few stories about these drives.  The most notable are:

1.  One drive that was  on its way to France fell out of the loading
    bay of a 707 to the ground.  Upon arivial in France, the drive
    worked even though it was shaped more like a parrallelogram instead
    of a box.  The heads were wrapped and locked in there retracted
    positions and survived the drop.

2.  While installing a 6600 system in Mexico, one of the Bryants fell
    through the floor.

The Bryant was the last of the big disk technology.  Shortly after it
14" technology arived on the scene, which lasted up until a few years
ago (yes I know there are some 14" drives still in production, but
the majority are much smaller now).

If you get some of that magnetic partical material that they use to
evaluate magnetic tape media and spray it on a portion of your disk
you should be able to read the bits.

Joe

Bytes/lb is left as an exercise of the reader.

In <1990Sep11.034940.16212@ecn.purdue.edu> 3ksnn64@cadlab.ecn.purdue.edu (Joe Cychosz) writes:

>The unit had 4 quadrants.  The quadrants were organized into a upper
>half and a lower half.  Each half used equal and oppsite positioning
>to conteract arm movement.

I think this is confusing the 6603 with the slightly later 6638.  The 6603
had just one positioner which moved all the heads in the same direction
at the same time.  I seem to remember the term "quadrants" associated
with the 6638.  The rest of the info on the 6603 matches my recollection.

The 6603's claim to fame was its very fast (by 1966 standards) transfer
rate: 1.4 Million 12 bit words a second (I think).  It did this by
reading/writing 12 heads in parallel.  Average access time: ~200
milliseconds, average latency: 32 milliseconds (900 RPM), so you had
to wait a while before you saw the high transfer rate.

To this day, every time I write a line of code which will cause a disk
access, I can hear the CLUNK, CLUNK of the 6603 as it moved the heads.

>My friend Don Crouse who installed a good many of these drives has quite
>a few stories about these drives.

Don would come to our site (University of Arizona), and work on his
Super-P diagnostic system while the local engineers took the disk apart.

Where is Don these days?  I haven't seen him in about 20 years.

One of my favorite 6603 stories is the time the engineers left a hydraulic
hose loose while they went to lunch, and came back to find the entire
contents of the hydraulic system (5 or 10 gallons) dumped under our false
floor.  The folks in the offices in the basement wondered about the
yellow stuff leaking onto their desks.  We just missed emulsifying the
entire building when the expanding puddle of fluid stopped short of a
very large air conditioning duct.

Ah, they don't make 'em like they used to.

Steve Jay
shj@ultra.com  ...ames!ultra!shj
Ultra Network Technologies / 101 Dagget Drive / San Jose, CA 95134 / USA
(408) 922-0100 x130	"Home of the 1 Gigabit/Second network"

My Kronos 2.0 instant says:

6603 and 6603-Mod-1 Disk Files
Equipment type: DA
Sectors/track:  64 in outer zone
                50 in inner zone
Tracks/device:  2048
Words/device :  7,471,104 (60 bit words)
Max Data rate:  61.1K wds/sec outer zone
                48.5K wds/sec inner zone
Transfer rate:  1.4 usec/word (12 bits) outer
             :  1.8 usec/word (12 bits) inner

I don't have a 6603 platter but my recollection
is that they were more like 1 meter in diameter
and the 6638 platter could have been around 26".
I have some 6638 platters at home so I might
remember to check their size.

There is a story (possibly apocryphal) that at some
site the heads crashed on a 6603 and the motors kept
turning. The friction is supposed to have ignited
a fire on the disk platters which (story has it)
contained aluminum and magnesium. Supposedly the
result was a computer room equivalent of a meltdown.
--
Richard R. Ragan (408) 496-4340
Control Data Corp., Silicon Valley Operations

I believe Steve Jay is right - the 6603 disk was bigger than 26 inches -
I thought I heard 'em referred to as 1 metre disks...

I first saw that particular peripheral attached to an RCA301 computer
(early solid state - contemporaneous with IBM 1401) and this was in turn
derived from a specialised military application referred to as "mobidic"
which consisted of aforementioned RCA301 with a Bryant Excello mounted
in back of a 5 ton truck - the name mobidic derives from "mobile disk drive".

RCA got the contract and made a civilian version with a Cobol compiler
which is where I came in...
--
Jitze Couperus          Control Data - Silicon Valley Operations
jitze@u02.svl.cdc.com   Voice (408) 496-4334  FAX (408) 496-4106

This is my personal favorite 6603 story. I wasn't there when it
happened, though. By the time I got there a year or so later, it had
been replaced with a 6638. (Every time I smell alcohol in the air, I
think of the hours and hours spent by C.E.'s buffing those platters!) 

As most of you (some of you? ANY of you?) will remember, the 6603 
platters were mounted with the axis of rotation horizontal, in a 
narrow cabinet with doors on the front and back. Well, to the 
carefully observant, there was ONE difference between the front and 
back doors: one had a metal pocket built into it for the manuals!

As the story has it, an (unnamed) C.E., had just finished with a repair 
of the 6603, and was replacing the doors (with it running, of course), 
and got them transposed. When the door with the manual pocket was 
closed (on the wrong end), the edges of the platters made contact with 
it, causing a rather obvious failure of the unit (screeching, smoke, 
etc.!). A rather long period of down-time supposedly followed...   :-)

And yes, Steve, you're right. They MOST CERTAINLY don't make 'em like 
they used to!
 -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
Gregory (Greg) E. Steele              (Internet):ges+@osu.edu
Network Engineer
The Ohio State University             (BITNET): STEELE@OHSTPY
Instruction & Research Computer Center
1971 Neil Avenue - Rm 406             Voice: 614-292-4843
Columbus, OHio  43210-1210            FAX:   614-292-7081

In article <1990Sep11.211524.2956@ultra.com> shj@ultra.com (Steve Jay) writes:
>In <1990Sep11.034940.16212@ecn.purdue.edu> 3ksnn64@cadlab.ecn.purdue.edu (Joe Cychosz) writes:
>
>>The unit had 4 quadrants.  The quadrants were organized into a upper
>>half and a lower half.  Each half used equal and oppsite positioning
>>to conteract arm movement.
>
>I think this is confusing the 6603 with the slightly later 6638.  The 6603
>had just one positioner which moved all the heads in the same direction
>at the same time.  I seem to remember the term "quadrants" associated
>with the 6638.  The rest of the info on the 6603 matches my recollection.

Yep!  A few more update facts and corrections.  As time goes by, the
numbers are all just a blur.

6603, had 39"x1/2" magnisium platters.  In each half there were 7 platters
(1 clock and 6 data/12 sides) rotating vertically.

A later drive, the 808 had 72 26" alluminum platters.  We had some of these
at Illinois also and I have a platter out of this.  This drive like the
later 6638 was devided into quadrants.  I believe there were about 10
of these drives made.

6638, don't know what size platters, was 800 Mbit drive and had 4x18
platters.  The disks spun at 1200 rpm and unlike the 808 used equal
and oppisite positioning as noted above.

>
>The 6603's claim to fame was its very fast (by 1966 standards) transfer
>rate: 1.4 Million 12 bit words a second (I think).  It did this by
>reading/writing 12 heads in parallel.  Average access time: ~200
>milliseconds, average latency: 32 milliseconds (900 RPM), so you had
>to wait a while before you saw the high transfer rate.

I measured my 6638 platter last night. It is indeed 26" in diameter.
Therefore, the original poster must have a platter from a 6638 (808)
or the related 821 (serial). 

I heard a 6603 story (possibly apocryphal) that at some site
the heads crashed and the motors kept on turning. Supposedly
the magnesium platters soon ignited and the equivalent of
"meltdown" occurred in the computer room.

6603 Tech specs from my Kronos 2.0 instant:
Equipment Type: DA
Sectors/track : 64 outer zone
              : 50 inner zone
Tracks/device: 2048
Words/device : 7,471,104 (60 bit words)
Max data rate: 61.1K wds/sec. outer
               48.5K wds/sec inner


--
Richard R. Ragan (408) 496-4340
Control Data Corp., Silicon Valley Operations

In article <25833@shamash.cdc.com>, rrr@u02.svl.cdc.com (Rich Ragan) writes:
> 
> Stuff deleted...
>
> I heard a 6603 story (possibly apocryphal) that at some site
> the heads crashed and the motors kept on turning. Supposedly
> the magnesium platters soon ignited and the equivalent of
> "meltdown" occurred in the computer room.
> 
> --
> Richard R. Ragan (408) 496-4340
> Control Data Corp., Silicon Valley Operations

I have another meltdown story to relate regarding CDC equipment.  A friend
of mine was doing performance testing on our then in-house Cyber 205, 
serial #501 (the first production machine).  At this time, the machine
had been installed in the Arden Hills computer room for several years, and
was frequently used as a testbed for new hardware updates, such as new memory
configurations.  

It seems that the in-house engineers had developed a non-standard method of
removing memory boards in a new type of memory unit, and over time the
connectors became slightly loose.  My friend began to run a very memory
intensive test that read/wrote patterns through various banks of memory as
fast as possible.  After this program had been running for some time, someone
in the computer room smelled smoke, and discovered that there was smoke
coming forth from the vents at the top of the 205 memory bay.  An emergency
powerdown was accomplished and everything "put out".  It was later surmised
that the increased current flow to/from the memories during the performance
test had heated the chips, then the boards, and then the connectors to the
point where some of the loose connectors began to melt.

Now that's a hot computer!


Zeke

(Apologies to Bernie if I got the details a little wrong, but I stand by
the scenario)

-- 
~~~~~~~~~~~ From the Shrine of the "Last Gasp of ETA Systems" ~~~~~~~~~~~~~
Extra zesty disclaimer:  MINE! MINE! ALL MINE! <chortle snort froth drool>
Robert K. "Zeke" Scott        internet: zeke@eta.cdc.com
Control Data Corp, Supercomputer Support Group

shj@ultra.com (Steve Jay) writes:
>One of my favorite 6603 stories is the time the engineers left a hydraulic
>hose loose while they went to lunch, and came back to find ...
  
 UH OH  HERE COMES THE NOSTALGIA AGAIN!
 I DONT THINK I'M READY FOR ANOTHER WAVE.
 
 CDC's been dead a long time now... dont you think its time to bury
 the corpse??  


-- 
/\=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=/\
\/Richard Friedman (415)540-5216  |     rchrd@well.sf.ca.us  \/
/\Pacific-Sierra Rsrch (Berkeley) | or well!rchrd@apple.com  /\
\/=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\/

In article <20298@well.sf.ca.us>, rchrd@well.sf.ca.us (Richard Friedman) writes:
>   
>  UH OH  HERE COMES THE NOSTALGIA AGAIN!
>  I DONT THINK I'M READY FOR ANOTHER WAVE.
>  
>  CDC's been dead a long time now... dont you think its time to bury
>  the corpse??  
> 
> -- 
> /\=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=/\
> \/Richard Friedman (415)540-5216  |     rchrd@well.sf.ca.us  \/
> /\Pacific-Sierra Rsrch (Berkeley) | or well!rchrd@apple.com  /\
> \/=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\/

I dunno.  Seems that somebody somewhere here keeps sending me 
a paycheck every once in awhile.  Don't know if it will last, but 
it does pay the mortgage for the time being.


Zeke

Opinions expressed herein are mine only, and expressly aren't
the expression designed to impress by my employer, who probably
isn't impressed by expression anyway.  Expressly impressively 
depressing, ain't it?

-- 
~~~~~~~~~~~ From the Shrine of the "Last Gasp of ETA Systems" ~~~~~~~~~~~~~
Extra zesty disclaimer:  MINE! MINE! ALL MINE! <chortle snort froth drool>
Robert K. "Zeke" Scott        internet: zeke@eta.cdc.com
Control Data Corp, Supercomputer Support Group

Re: nostalgia wave... 

If you don't like history, don't read it.

Personally, I like it.  My thanks to all who responded to my posting.

Ralph Carpenter
Tektronix, Inc.
Beaverton, OR

In article <25835@shamash.cdc.com> zeke@shamash.cdc.com (Robert Scott) writes:
>
>I have another meltdown story to relate regarding CDC equipment.  A friend
>of mine was doing performance testing on our then in-house Cyber 205, 
>serial #501 (the first production machine).  At this time, the machine
>had been installed in the Arden Hills computer room for several years, and
>was frequently used as a testbed for new hardware updates, such as new memory
>configurations.  
>
>It seems that the in-house engineers had developed a non-standard method of
>removing memory boards in a new type of memory unit, and over time the
>connectors became slightly loose.  My friend began to run a very memory
>intensive test that read/wrote patterns through various banks of memory as
>fast as possible.  After this program had been running for some time, someone
>in the computer room smelled smoke, and discovered that there was smoke
>coming forth from the vents at the top of the 205 memory bay.  An emergency
>powerdown was accomplished and everything "put out".  It was later surmised
>that the increased current flow to/from the memories during the performance
>test had heated the chips, then the boards, and then the connectors to the
>point where some of the loose connectors began to melt.
>
>Now that's a hot computer!
>
>
>Zeke
>

Yes, these details are pretty much correct. The program that was executing 
heated up the memory boards the farthest from the heat sensors on the machine.
The rest of the memory frame apparently cooled the total frame so that the
heat sensor never went off. When the board finally overheated, the resin in
the board set the whole memory frame on fire. In addition, when the machine 
caught on fire, the smoke poured from the machine and went right past
the smoke detectors. THEY NEVER WENT OFF !!!!

However, two years later a fellow countryman of mine from down under
continued the tradition on a air cooled ETA10. On this machine, also
a prototype, the CPU board (There is only one board per CPU in a ETA10)
was wirewrapped. There were several routing corrections made on the
surface of the 44 layer board. One night both of us were each running on 
one of the two CPU's in the machine when he burned a hole the size
of an American quarter through the CPU board.

To my knowledge these were two of the three fires caused in the
CYBER205/ETA10 machines. The other one was a production CYBER 250
at ETA Systems, Inc.

They were really "HOT" machines from a performance and experience
point of view.

Bernie King-Smith
(The WOMBAT)
Former System Performance Analyst ETA Systems, Inc.

Disclaimer: This posting is only from my experience and does not
reflect on the opinions of my current employer.

P.S.  Sorry Peter if the details are not completely correct !!!!

As to why the old folk keep babbling on about the bizarre old disks--hey,
they were interesting bits of engineering and design, and they sure wrung a
lot of performance from relatively unsophisticated technology!  They also
show some impressive numbers here and there (like the spindle drive motor
on the 6603, or the number of heads on the 6638).  But fear not, you young
'uns; we don't have very good memories, so pretty soon we'll forget what we
were talking about and the thread will die out.  In the meantime, here's
more detail than you wanted about the 6603 (the really strange one) plus
enough about the 6638 to distinguish it, with a few anecdotes sprinkled in
to keep it from getting too dry.  I've included as many numbers as I had
handy; you can use them to calculate out whatever you want to know about
these dinosaurs.  If you're looking for still more numbers or details, send
me a note--I worked with the '03 and I'm in touch with someone who did a lot
with the '38.

6603:
=====

This is the bizarre Bryant disk with the huge platters, horizontal spindle,
and hydraulic-fluid-actuated positioner.  The platters were indeed 39" in
diameter, about 1/4" thick, and a careful measurement of weight and volume
says that they are pretty close to pure magnesium.  One platter plus the
steel collar used to hold it to the spindle weigh out at about 28 lb. 
There were 14 platters on a spindle, so adding in the spindle itself, the
rotating disk assembly weighed > 400 lb.  You might ask "how the hell did
they turn it?"  The spindle drive motor was 8 hp.  It drove the spindle
with a set of V-belts (five, if memory serves).  Fun fact:  The spindle
hole in a platter is about 5.5" in diameter, so you can drop an entire
modern disk drive which is faster and higher-capacity than the 6603
through the spindle hole.  The drive, in cabinet and all, weighed just a
bit under two tons.

	|||||||   |||||||
	|||||||   |||||||
	=================	spindle supported, driven at center
	|||||||   |||||||
	|||||||   |||||||

Both sides of all platters were used--28 surfaces.  But two of the surfaces
were for clock tracks and two surfaces (one per "side" of the drive) were
"spares" that could replace a damaged surface.  Data transfer was to/from a
set of 12 heads in parallel; this helped the transfer rate considerably.

There were 4 heads per surface.  Outer heads had 128 sectors; inner had
100.  Sector size was actually variable, but all the systems I'm aware of
used a fixed sector size of 64 CM words or 320 12-bit (PP) words, out of
the maximum of 348 data words.

Rotational speed was supposed to be 900 rpm, though I remember seeing our
mod-IIs running at 960.  Anyway, that's 15 or 16 rps, so we're in the range
of 60-70 ms for a rotation.  Because of the need to bounce the data thru a
PP to get to main memory, the normal organization was to interleave sectors
1:1.  This gave a useful transfer of 64 sectors per rev, which if you cal-
culate it out and tweak to today's norm of 8 bits/byte, is a bit under half
a megabyte (8-bit bytes) per second.

Positioning was via a hydraulic (fluid) servo, with 7 bits controlled by 7
solenoid-actuated valves (128 cylinders).  The seek time was originally
independent of distance (because of settling considerations), although it
was influenced by rotational position--you had to wait for index after
getting on track.  One of the changes between the original and mod-II
drives was that the mod-II allowed reading during a seek.  The point of
this was that you could start a seek, wait a while, then start reading.  As
soon as you'd read 3 sectors in a row correctly, you were on track!  (The
number 3 came from the mechanical characteristics of the positioner--it
assured that you'd have watched through a complete oscillation as it
settled.)  Typical seek time was 250 ms on the original, 200 ms on the
mod-II.

The useful capacity of the drive, using the usual fixed sectors, was:
	24 surfaces
	* 128 cylinders
	* (2 heads @ 128 sectors) + (2 heads @ 100 sectors)
	* 320 bits/sector (remember: parallel transfer)
	/ 60 bits/word
or about 7 mega-words.  Translating from those words (60 bits) to contem-
porary measure of 8-bit-bytes, it was effectively a 53-Mb drive.  That
says a single coffee-table-sized platter held about four and a half meg.

About the platters catching fire:  Has anyone ever tried to ignite a large
chunk of magnesium?  It's not easy.  In fact, it's very difficult because
it conducts heat pretty well; moreover, the metal tends to skin over if
given a chance--you can manage to melt magnesium with a torch without
igniting it.  Thin pieces of metal or shavings are a different story, of
course.  But I suspect the stories of a fire in a 6603 are apocryphal.

6638:
=====

The 6638 had smaller platters (26 inch, and much thinner) in a more
conventional vertical-spindle arrangement.  There were 72 platters in all,
mounted on two spindles with separate motors.  Each spindle had 18 platters
above and below the motor.  Head-arms and positioners were between the
spindles.  There were two positioners which could operate independently.
The 18-platter groups were further divided into pairs of 9's (so that the
positioner mechanism sat between upper and lower parts, making it
symmetric).  9 platters == 18 surfaces, of which 16 were used for data.

	---|---              ---|---
	   |   <-Positioner->   |   		Each ---|---
	---|---              ---|---		represents 9 platters
	 Motor                Motor
	---|---              ---|---
	   |   <-Positioner->   |
	---|---              ---|---
There were 6 heads per surface.  Now, stop a minute and multiply that out:
6 heads * 16 surfaces/group * 2 groups per quadrant * 4 quadrants == 768
read/write heads!  The geometry here was different:  The transfer was still
12 bit parallel, but used 3 heads/surface on each of 4 surfaces for the
12-bit transfer.  There were 32 "cylinders" (head positions), which gave
the 38 a better seek time than the 03.  As with the 03, sector size is
variable, but with a simplistic layout you'd have 100 sectors/track, and
the total capacity becomes:
	768 heads
	* 32 head positions
	* 100 sectors
	* 320 bits/sector
	/ 60 bits/word
or about 13 mega-words.  (With a more sophisticated layout, the 38 had just
about twice the capacity of the 03.  At maximum capacity, this behemoth was
the equivalent of today's 128 Mb in 8-bit-bytes.)

The 6638 turned a little faster--just under 1200 rpm.  Seek was much
faster--110 ms max.  Data transfer was faster--1.18 usec per 12-bit PP word
(vs 1.4 / 1.8 for the 03).
-- 
Dick Dunn     rcd@ico.isc.com -or- ico!rcd       Boulder, CO   (303)449-2870
   ...Worst-case analysis must never begin with "No one would ever want..."