> -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:[EMAIL PROTECTED] On Behalf Of Paul Gilmartin > Sent: Thursday, July 12, 2007 1:57 PM > To: [email protected] > Subject: Re: Track size and maximum single volume data set size > > > On Thu, 12 Jul 2007 14:34:17 -0400, J R wrote: > > >Well, I was always aware of the trade-offs, i.e. bit density > >at the center v. bit density at the outside, but I wasn't > >aware that anything was ever done about it with variable > >data rates, etc. > > > CD players, like the original Macintosh 390 K floppy disks, > vary the angular velocity inversely with cylinder radius > in order to have both uniform linear density and uniform > data transfer rate. > > -- gil
Right. Disk drives are generally CAV - Constant Angular Velocity - aka the RPMs never change (not, not Redhat Package Manager files for you Linux people <grin>). Optical drives (CD, DVD?) seem to be CLV - Constant Linear Velocity. -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology The information contained in this e-mail message may be privileged and/or confidential. It is for intended addressee(s) only. If you are not the intended recipient, you are hereby notified that any disclosure, reproduction, distribution or other use of this communication is strictly prohibited and could, in certain circumstances, be a criminal offense. If you have received this e-mail in error, please notify the sender by reply and delete this message without copying or disclosing it. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
