Path: utzoo!utgpu!attcan!uunet!lll-winken!ames!xanth!nic.MR.NET!umn-cs!umn-d-ub!rutgers!att!alberta!ubc-cs!van-bc!tessera!seacbc!wain
From: wain@seacbc.UUCP (Wain Dobson)
Newsgroups: comp.unix.microport
Subject: Re: Enix doesn't work with my 300 MB disk (*sigh*)
Keywords: 1024 Cyl max
Message-ID: <174@seacbc.UUCP>
Date: 25 Jan 89 22:31:32 GMT
References: <381@intek01.UUCP> <1966@qiclab.UUCP>
Reply-To: wain@seacbc.UUCP (Wain Dobson)
Organization: SEAC Software Engineering, Vancouver, B.C., Canada
Lines: 46

In article <1966@qiclab.UUCP> neighorn@qiclab.UUCP (Steve Neighorn) writes:
>In article <381@intek01.UUCP> mark@intek01.UUCP (Mark McWiggins) writes:
>>But I have a 380 MB ESDI drive (CDC 94186-383H + DTC 6280 controller)
>>with 1224 cylinders, and Enix only recognizes 1024.  Not only that, it
>>keeps bad a SECTOR table and not a bad TRACK table, and there can be
>
>My experience with SYS V Release 3.2 is that it won't support more than
>1024 cylinders without doing some sort of logical sector remapping. Now
>there may be versions from certain vendors that do support > 1024 cylinders,
>but the Bell Technologies 3.2 I have used will not. Some ESDI controllers
>will allow you to convert 1224 cylinders x 15 heads x 36 sectors per track
>into 654 cylinders x 16 heads x 63 sectors per track. The Western Digital
>1007 ESDI controller and the Adaptec 2322 ESDI controller both have this
>ability.

My experience is limited to the Miniscribe and DTC controller. However, by
mapping to 60 sectors per track, both Bell Tech 3.0 and Microport 3.0e have
responded. As well, using the DTC in native mode which provides 1222 with 2
for housekeeping, SCO 2.2.2, Bell Tech 3.0 and Microport 3.0e have responded.
In all case, sector sparing was used (34 + 1).

One problem that I have run into but, I am not sure whether it was the luck of
the draw when obtaining a Miniscribe or a goofy controller, is that the low
level would proceed normally however, both Bell Tech and Microport scans would
find sectors with no ID. Given that the low level does encoding and the
controller scan is to pick this up, I am a bit ???.

Also when using the DTC native mode without 60 sector remapping, the controller
would format 1222 and scan 1024, with Microport scanning the remaining sectors,
all 198 of them. Consequently, Microport's scan did not deal with 1024 tracks
and, if bad sectors appeared in this 1024 that were not accounted for by the
controller Microport would only know about them just before issuing a 
hd read/write error.

To cap this off, for SCO 2.2.2 I low levelled the Miniscribe with the DTC native
mode, 1222 cylinders, installed SCO using their custom table. This was last
August. But, after playing with the idea for a while, I might low level with
the 60 sector mapping, just to see what happens. Note SCO 2.2.2 is the ESDI
version.

****
My opinions, well ....

-- 
Wain Dobson
	...!{uunet,ubc-cs}!van-bc!tessera!seacbc!wain