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From: lairdb@crash.cts.com (Laird P. Broadfield)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: More than two HDDs  (was Re: IDE vs SCSI vs ESDI vs ???)
Message-ID: <1991May30.191724.21710@crash.cts.com>
Date: 30 May 91 19:17:24 GMT
References: <1991May29.194400.8044@aero.org> <43881@netnews.upenn.edu>
Organization: "Well, a head on top, an arm on each side, two legs...."
Lines: 23

zampetti@eniac.seas.upenn.edu (Marc Zampetti ) writes:

>	Good for you. Moving out of MFM and RLL is the best thing you can
>do when you are upgrading. The choice of drive you want will depend
>upon the size you are willing to go for. If you want something from 40 to 
>150 Mb, then IDE is the way to go. It is fast, usually 15-20ms and fairly
>cheap, I've seen 120Mb IDE kits for about $500. You can connect two
>IDE drives to the same system, but you have to be careful about 
>compatibility, becuase IDE is not completely standard. SCSI is just as fast
>as IDE, but will cost a little more for the same stoarage range. But, if
>you want greater than 150Mb, SCSI will probably be cheaper. The good thing
>about SCSI is that one controller can usually drive up to 8 drives. You can
>daisy chain them, even external drives, fairly easily. ESDI is the best for 
>very high capacity, greater than 600Mb. This usually come with fast caching
>controllers. They are the best cost wise once you get into the high capacity
>area. I hope this helps.

That's about what I would have said, from the experiences I've had.  My 
question is how do you manage more then two physical drives in the AT
architecture?  The built-in setups invariably only specify two physical
HDD units; are we talking about device drivers here?  If so, how do you
get them to work on ESDI?  WD seems to think that their controllers
won't stack (interrupt and address conflicts, etc.)