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From: UCSLCT@UWPLATT.EDU (LANCE TAGLIAPIETRA)
Newsgroups: comp.os.cpm
Subject: disk drives
Message-ID: <99FDA6FD0BBF800905@uwplatt.edu>
Date: 8 May 90 20:43:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 21

Rex_E._Robards.DlosLV@Xerox.com writes:
 
<1.44 MB diskettes have 18 sectors per track.  720 KB diskettes have 9
<sectors per track.  3.5" drives and 5.25" drives have the same pinouts
<(they are indistinguishable).
 
Yes, I understood from the article that 1.44Mb disks are putting 18
512 byte sectors on a track, and 720Kb disks are putting 9 512 byte
sectors on a track. The article explains that the data rate is
doubled.
 
What is physically different between a 1.44Mb drive and on that is
rated at 720Kb?   Why can one handle the doubled data rate, and not
the other?
 
Looking at a 3.5in drive here, I would say that the pinout has to be a
bit different than a 5.25in drive, and the 3.5in drive has no power
connector like the 5.25in (at least the ones connected to the ps/2's
here don't).
 
Lance Tagliapietra  ucslct@uwplatt.edu or ucslct@uwplatt.bitnet