Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!wuarchive!texbell!merch!cpe!adaptex!neese
From: neese@adaptex.UUCP
Newsgroups: comp.sys.ibm.pc
Subject: Re: (none)
Message-ID: <6100013@adaptex>
Date: 11 Sep 89 14:34:00 GMT
References: <4788@brains.UUCP>
Lines: 40
Nf-ID: #R:brains.UUCP:4788:adaptex:6100013:000:1520
Nf-From: adaptex.UUCP!neese    Sep 11 09:34:00 1989


>Which controler? SCSI, ESDI, ADAPTEC, or PERSTOR for an AT Compatible.
>  I am having trouble deciding upon the "optimal" Hard Disk or Hard/Floppy
>controller for my AT compatible. Is it true that SCSI has the highest
>transfer rates/second?

SCSI data rates are dependent on the host adapter, the drive, and sometimes
the CPU.  If you are using a dumb host adapter, then the rates will depend
on the CPU and drive.  You can get data rates anywhare from 400KB/sec to
3.5MBytes/sec (at the BIOS level).

>Are the Seagate drives with the "N" letter tacked onto
>the number just reworked RLL drives?

Most SCSI drives use RLL 2,7 as the encoding scheme, and some use a variation
of this call zone bit recording (ZBR) to get more than one clock rate on the
drive and increase the capacity of the drive.

>Why does the controller Seagate makes for these drives so cheap?

It is a dumb host adapter, requiring the CPU to do all the work.

>And is SHAMROCK of Westlake Village, California a
>reputable company to deal with?

Unknown.

>I am trying to assemble a Hard Disk system in
>the 65 - 80 Mb range with approximately 17-28 Ms access time. Any help is
>appreciated. 

My personal preference, (and its not due to the fact that I work for the
company) is the AHA-154xA with the Quantum Pro80 (80MB 3 1/2" 19ms) drive.
This is a great performance combination.  Data rates up to 3.2MBytes/sec.


			Roy Neese
			Adaptec Central Field Applications Engineer
			UUCP @ {texbell,attctc}!cpe!adaptex!neese
				merch!adaptex!neese