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From: nigel@minster.UUCP
Newsgroups: net.micro.atari16
Subject: Re: Comparing hard disks
Message-ID: <726@minster.UUCP>
Date: Fri, 14-Mar-86 05:53:35 EST
Article-I.D.: minster.726
Posted: Fri Mar 14 05:53:35 1986
Date-Received: Mon, 17-Mar-86 04:21:48 EST
References: <743@well.UUCP>
Reply-To: nigel@minster.UUCP (nigel)
Organization: University of York, England
Lines: 35

In article <743@well.UUCP> wvucenic@well.UUCP writes:
>I'm interested in the 20Meg Atari hard disk.  I had heard rumors to
>the effect that the developers hard disks have a faster data transfer rate
>than the soon-to-be-available commercial 20Meg Atari hard disks.  I asked
>about this at my local dealer, but the fellow there told me that the
>only differences were cosmetic: metal case vs. plastic case.  I'm not sure
>he's got the straight story on data transfer rates, as he was quoting
>10Mbits/sec to me.  I realize that the DMA controller can transfer at that
>speed, but I had heard that the hard disk controllers were actually
>running at 7.5Mbits or 5Mbits.
...
The developers drives have two boards in - a standard hard drive controller,
and a bus convertor board. I was told around Christmas time that before
selling commercially, Atari wanted to get this onto one board, and into a
plastic case, so your dealer is on the right lines. 5MBits is the quoted
rate for the drive, but some timings I made using an analyser (very rough)
suggested the acknowledges were closer to 7MBits. If Atari wish to use a
single board, then the new board may be faster. The developer setup looks like
a standard SASI board, with a SASI to Atari convertor (one PAL, about 6 TTL).

>		Anyway, back to hard disks... the developers hard disk I
>		looked at had a fan that seemed to be about average for
>		fan noise.)

Yes - average, fine by me.

>
>Other differences of more minor interest would include requirements for
>parking the heads.  I understand that the developer's hard disk requires
>this, but I can't imagine that a commercial version would.

There is a utility to move the heads to a safe landing point (!) for
transport. The importance is not heavily stressed, just suggested.

Nigel Roles