Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!cs.utexas.edu!uunet!zephyr.ens.tek.com!tektronix!tekcrl!tekgvs!keithe
From: keithe@tekgvs.LABS.TEK.COM (Keith Ericson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Do not order from PC-BRAND
Message-ID: <5621@tekgvs.LABS.TEK.COM>
Date: 21 Jul 89 15:55:43 GMT
References: <459@mountn.dec.com>
Reply-To: keithe@tekgvs.LABS.TEK.COM (Keith Ericson)
Distribution: usa
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 20

In article <459@mountn.dec.com> m_belanger@mosaic.dec.com writes:
>I have a Miniscribe 3180E hard disk,
>which is not supported under DOS since it's greater than 1024 cylinders.

With a properly-designed interface card the >1024 cylinders
restriction is circumvented by re-mapping the 17, 26 or 34 "real"
sectors per track to 52, 54 or 63 "logical" sectors per track. 
Also, the "real" head count can be translated to a "logical" 15 or
16.  Then you can do

           Formatted Capacity
       ----------------------------
	512 x [15|16] x [52|54|63]

to get a "logical" cylinder count of < 1024.

Playing these tricks with maximum values permits a maximum
per-drive capacity of approximately 528 Megabytes.

kEITHe