Date   : Fri, 29 Mar 1991 15:06:55 GMT
From   : zaphod.mps.ohio-state.edu!samsung!noose.ecn.purdue.edu!mentor.cc.purdue.edu!gauss.math.purdue.edu!wilker@tut.cis.ohio-state.edu (Clarence Wilkerson)
Subject: Re: Help: Documentation, information, et cetera.

Sorry, no experience with Zeus MP/M type stuff.
However, on the subject of disk drives, any St-506
innerface drives I've used will cheerfully allow you to
use them at less than full capacity. So if the number of
logical heads is less than or equal to number of physical
head, and same for cylinders, almost any other
drive should replace the ones you have. For example,
Seagate ST251 's have 6 heads, and 820?? cylinders, and
are going new for about $250. Unfortunately, the cheaper
bargain drives such as ST225 only have four heads and would
not plug right in. 

If the drive controller is SCSI, then the operating system
may think it reading a certain track and sector, but actually
eventually asks for an absolute sector number, so if the
scsi controller has set the correct parameters the operating
system would not know what it has physically. 

Poke around under the hood and see what kind of hard disk
controller is there?
Clarence