I remember visiting a place with one hooked to a 360/75. "Wow," I said,
"400 megabytes." The response was, "No, 200. Everything is backed up!"
Chuck Stevens wrote:
> The US Veterans Administration Data Processing Center in Austin, Texas
had
> *at least* three -- maybe at one point five -- of these beasts (one on a
> 360/40, two on a 360/65, maybe two more at one point on a 360/50)..
>
> I was an operator on those systems at the time -- late 1960's.
>
> Although speed was a big problem with the (as I recall) 2321 Data Cell
> Drive, a bigger problem was reliability. They had a nasty tendency to
> "crunch" strips, and when that happened, the strip had to be recreated
from
> backup. This was virtually a daily occurrence in our shop. I think we
had
> a fully-2321-trained IBM engineers on site for two of the three ****fts,
and
> another on call for the third ****ft, seven days a week.
>
> The first heavy production jobs -- I can't remember whether it was
logistics
> & supply or VA ****tfolio loans -- took something like ten hours for the
> daily processing on a 360/65, if it ran successfully. It didn't usually
do
> so, and after a month of trying we were a month behind. At that point,
each
> 400mb 2321 was replaced by a pair of "pizza-oven" 2314's with about the
same
> 400MB capacity, and much greater speed and reliability. Daily
processing
> dropped to three hours or less, and restorations from backup were almost
> unheard of.
>
> Part of the difficulty, I think, was that they used the devices for ISAM
> files with the indices in three of the ten bins and the data in the
other
> seven, so every record access required a "double pick", one on each side
of
> the array of strips. This was an application design issue; the device
works
> fine for "online inquiry", but not as a batch DASD device.
>
> I think the Texas Department of Public Safety also had one or more of
these;
> from what I heard at the time their (occasional online inquiry)
application
> was better suited to the device than the VA's were.
>
> -Chuck Stevens
>
>
>
> <mauzbiz@[EMAIL PROTECTED]
> wrote in message
> news:1146781586.864406.79400@[EMAIL PROTECTED]
>> Worth remembering for "musem-quality" items is the mid-1960's IBM
>> random access "data cell", scarcely known and little deployed, that was
>> like a round carousel juke box that spun hundreds of magnetic strips
>> around until the chosen one was wrapped around a read/write head from
>> whence data could be read or to which data could be written. The
>> device had a capacity of 400 megabytes, far more random access storage
>> than most shops had online at any given time, and could access any data
>> in a few seconds. But it was expensive and I suspect attracted little
>> interest because most applications in those days were happily running
>> with an input tape, transaction tape or cards, and an output tape, and
>> companies were only beginning to explore random access files for
>> certain limited purposes, given the cost per megabyte.
>>
>> RCA had a version of this type of device, which, under certain
>> cir***stances of motion (back and forth), would inadvertently drop some
>> of its strips out the back of the machine, and some clever techie
>> programmed such a sequence and then announced to the operator "I've
>> lost one of my strips, could you please come over and help me out."
>>
>> I remember our IBM data cell from a summer job at California Western
>> States Life Insurance Company in Sacramento in 1966.
>>
>> It would be fascinating to bring into a musem such a first attempt at
>> leapfrogging the extremely limited 7 megabyte limitation that most
>> random access devices (usually removable disk pack drives) had even
>> into the late 1960's. Like bubble memory, its capabilities were
>> surpassed by other technological improvements and it never found a
>> significant niche.
>>
>
>
|
