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- Path: news.compuserve.com!newsmaster
- From: mimetz@amiga.de (Michael Metz)
- Newsgroups: comp.sys.amiga.misc
- Subject: Re: A4000 HD Drive, I was wrong AT! NOT !!
- Date: Sat, 24 Feb 1996 16:18:29 GMT
- Organization: AMIGA Technologies GmbH
- Message-ID: <4gndnc$cts@dub-news-svc-6.compuserve.com>
- References: <4ej2ve$pul@coranto.ucs.mun.ca> <4enarpINNnfj@maz4.sma.ch> <2539.6617T962T704@globalxs.nl> <4froap$5fg@natasha.rmii.com> <4g0ph3$tv5@coranto.ucs.mun.ca> <4g1c6k$rte@natasha.rmii.com>
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-
- mdaymon@rainbow.rmii.com (Maxwell Daymon) wrote:
-
- >George Noel (gnoel@morgan.ucs.mun.ca) wrote:
- >: Maxwell Daymon <mdaymon@rainbow.rmii.com> wrote:
- >: >It's all in the controller. The drives that came with the Amiga
- >: >originally were standard PC drives with a diskchange line.
-
- >: Then why is everyone complaining about the price if the drives were the
- >: same? What was so different about the drives that made them more
- >: expensive or was the controller driving the price up?
-
- >I'm speaking of the double density drives. When the Amiga came out, you
- >could replace the internal drives with standard diskchange supporting PC
- >drive. The controller in the Amiga is Paula, and as a custom chip with
- >audio support, she's more expensive than a run-of-the-mill disk controller.
-
- >The HIGH density drives were special modifications of standard clone HD
- >drives, specifically the Chinon FB-357 and the FZ-357. Both drives are
- >commonly found in clones, except the Amiga version of the drive supports
- >half-speed transfers in high density mode (Paula can't keep up)
-
- >That's the only change. There is nothing special about the drives in the
- >Amiga that allow them to format to 880k (DD) or 1760k (HD). That is the
- >result of the Amiga (Paula) not using/needing real sector gaps.
-
- >The Amiga reads a track at a time and decodes the MFM or GCR data at the
- >OS level. The typical PC controller reads a sector at a time and sends
- >ALREADY DECODED data to the OS. This is AFAICR. I haven't even looked at
- >it in a while.
-
- >: So this "half the speed" ability added to the drive made it cost more
- >: but if Paula was modified to read data at 500kb/s we could use the same PC
- >: drive but get the same performance?
-
- >If Paula could handle a sustained 500kbps, we could drive down to Computer
- >City or your favorite PC chain store and buy a standard PC HD drive and
- >stick it in the Amiga. We'd get full speed transfers, 1760k per HD disk,
- >and a normally priced drive.
-
- >Just replacing the Paula may not work - there's no promise that a fast
- >Paula would work correctly with the rest of the Amiga. A new Amiga with
- >an enhanced Paula would work.
-
- Thanx.. this all is correct!
- because the redesign of the PAULA will take a while, we are
- investigating in _every_ scematics we find to run HD on the AMIGA
- again... but this takes some time as well.
-
- >mdaymon@rmi.net
-
-
- -----------------------------------------------------------
- Michael Metz/AMIGA * Technologies GmbH * Berliner Ring 89
- D 64625 Bensheim * Tel: +49 (0)6251-802 100 * Fax:.-802 179
- Priv.: 71001.210@compuserve.com * Company: mimetz@amiga.de
-
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