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From: davidsen@sixhub.UUCP (Wm E. Davidsen Jr)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: What is IDE?
Message-ID: <2595@sixhub.UUCP>
Date: 13 Dec 90 02:48:27 GMT
References: <20104@rouge.usl.edu> <2553@sixhub.UUCP> <1990Dec10.175003.17183@amd.com>
Reply-To: davidsen@sixhub.UUCP (bill davidsen)
Distribution: usa
Organization: *IX Public Access UNIX, Schenectady NY
Lines: 43

In article <1990Dec10.175003.17183@amd.com> phil@brahms.amd.com (Phil Ngai) writes:

| If you want to sit around and theorize, then also consider that IDE
| has the advantage over ESDI that it can (and does) use Zone Bit Recording,
| where the outer tracks hold more sectors than the inner tracks since
| they are longer. (SCSI can do this too but I disrecommend SCSI at
| this point for lack of standards. I could be wrong, however.)

  As long as the ZBR is hidden so that the disk looks as if it has a
constant number of sectors, most software will be able to handle it. A
someone noted, you can't reformat the IDE drives, or actually, you need
some special software and possibly hardware to do it.

  We mix drives and controllers with SCSI and seem to have no trouble
with it. I'm not sure what you mean by lack of standard. The Mac disk
interface is SCSI, and there doesn't seem to be a problem.

| If you want to look at actual prices, which is what I think counts,
| the small (40 to 80) meg IDE drives are very attractively priced.
| 
| So I wouldn't put IDE down like that.

  I made that point, and you even quoted me, so I'm not sure how I'm
"putting them down."

| >  For one drive the total system cost is probably lower than an
| >equivalent esdi, so it's not a liabinity if you can live with just one
| >of the little drives. If you need capacity in the GB range, you lose.
| 
| You would think that the controller cost would be constant and so for
| the larger drives, a smaller percentage of the total cost, meaning IDE
| ought to be a better buy in the larger sizes. But I admit I haven't
| looked at the price of large IDE drives.

  I haven't seen any drives larger than about 208MB, and certainly not
the big cheap drives you get with ESDI. I thought my 320MB for $900 was
neat until I saw someone in _PC Week_ dumping Wren's for 766MB/$1450
and 1.2GB/$1950. Now *that's* cheap.
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc and 80386 mailing list
"Stupidity, like virtue, is its own reward" -me