Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!evax!utacfd!merch!cpe!adaptex!adaptx1!neese
From: neese@adaptx1.UUCP
Newsgroups: comp.periphs.scsi
Subject: Re: Adaptec AHA-1740 on ISC 2.2 ?
Message-ID: <283400090@adaptx1>
Date: 1 Apr 91 22:27:05 GMT
References: <24469@ajfcal.uucp>
Lines: 41
Nf-ID: #R:ajfcal.uucp:24469:adaptx1:283400090:000:1732
Nf-From: adaptx1.UUCP!neese    Apr  1 09:07:00 1991


>>>/* ---------- "Re: Adaptec AHA-1740 on ISC 2.2 ?" ---------- */
>>>
>>>>pim@cti-software.nl (Pim Zandbergen) writes:
>>>
>>>>>Will the Adaptec AHA-1740 EISA SCSI host adapter run with ISC UNIX 2.2 ?
>>>
>>>Does anyone know if it will also work under SCO Unix 3.2.2 ?
>
>>Yes.  It has been thoroughly bashed under SCO 3.2.2.
>
>
>Why does the 1740 spoof head/cylinder numbers? I have a 670 MB Hitachi
>drive tied to the Adaptec. When the hard disk setup shows you the drive
>configuration, it indicates 64 heads and ~630 cylinders. This looks like
>a "1024 cylinder spoof" since the Hitachi drive has more than 1024
>cylinders. Unfortunately, you cannot enter the drive defect table unless
>you know the spoofing algorithm.
>
>The Adaptec bios cannot be turned off - if it is turned off, it will
>not run under ISC.
>
>Is there any way to turn off the spoofing???
>
>Other than this VERY serious configuration problem associated with (i think)
>the Adapted bios, ISC unix runs the Adaptec quite nicely....

This is not a configuration issue.
The reason you cannot turn this off, is due to the SCSI interface itself.  SCSI
presents itself as a logical block interface.  There is no cyl/head/sectors
numbers that would make any sense for the SCSI bus.  So we present the numbers
so DOS can function and OS/s that support DOS partitions to function as well.
On the defect list.  SCSI drives all appear to be error free to the OS.  They
take a bad sector and replace it with a spare on the disk.  This is done
transparently to the OS, sometimes on the fly, sometimes not, but always at
format time.

			Roy Neese
			Adaptec Senior SCSI Applications Engineer
			UUCP @  neese@adaptex
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