[Wftl-lug] A trip down computer memory lane

[Philip Nelson]

It may interest you to know that those of us who still work on the mainframe 
still size our files and databases in "cylinders" and "tracks".

I remember examining a disk from a 3380 disk pack which had had a "head crash" 
(literally the head had crashed onto the platter and gouged a significant 
groove in it).

Even although 3380s and 3390s are now long gone, the modern storage still 
allocates "volumes" as if they were 3380s, obviously emulated.   So your 
storage may be a big SAN with RAID disks, but to the mainframe you see it as 
multiple 3380 volumes.    

From memory a "cylinder" is 695k (for a standard 3380 : different models had 
different configurations).

HTH

Phil   

On Sunday 19 August 2007 18:36, Carl Lowenstein wrote:
> On 8/19/07, Ole Kofoed Hansen <ole+wftl at tuxino.dk> wrote:
> > That reminds me of some of the stuff I've seen.
> >
> > In the basement of a computer club, I was once a member of, there was
> > a disk pack, quite similar to the one seen here:
> >
> > http://www-03.ibm.com/ibm/history/exhibits/storage/storage_PH3850B.html
> >
> > We were told that it was a 64KB disk, but I'm not so sure about that.
>
>  More like 100MB for the 3330 disk pack, or 200MB for the 3336.
>
> < http://en.wikipedia.org/wiki/IBM_3330#IBM_3330 >
>
> I did once have a 64kB disk drive for a PDP-11.  It was a
> head-per-track drive so there was no time wasted in seeking to another
> track.
>
>     carl