Path: utzoo!attcan!uunet!aplcen!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!usc!snorkelwacker!ira.uka.de!smurf!gopnbg!tmpmbx!netmbx!hase
From: hase@netmbx.UUCP (Hartmut Semken)
Newsgroups: comp.sys.atari.st
Subject: Re: infos wanted about adding drive in megafile30
Keywords: megafile AHDI drive
Message-ID: <785@netmbx.UUCP>
Date: 10 Jun 90 18:15:10 GMT
References: <5385@chorus.fr>
Reply-To: hase@netmbx.UUCP (Hartmut Semken)
Organization: netmbx, Berlin, West Germany
Lines: 42

In article <5385@chorus.fr> ciceron@chorus.fr (Carrez Stephane) writes:
>	One month ago, Claus Brod has posted in comp.sys.atari.st an article about
>adding a new drive in the megafile 30. I'd like to add another drive but
>I have several problems about drive compatibility.
>
>	o if the new drive has not the same capacity (30Mb), suppose
>	20Mb, how does the driver (basically the i8085) recognize the new
>	size? (recognition of # of heads, # of cylinders ?)

No problem: the kind of the disk is stored somewhere on the disk by the
controller. The controlelr will find out!

>	o if the new disk seek-rate is different (prefer faster), will
>	this new seek-rate be recognized (without any effect on old disk)?

Yes, it will. Most likely, You'll use the ame seek rate code.
Seagate (really Seagate?) implemented a "new" seek sheme in the ST412:
step pulses are sent every 24 (17 today) microseconds and remembered by
the drive; when the dive has done the seek, it tells to the controller
on the "seek completed" output.

>	o I have noticed in my megafile30 that there is a 16 pins
>	connector with a full line (8pins) connected to ground and the
>	others connected to the i8156 (2 // ports + timer). (near the 64K
>	eprom). I beleive that this is supposed to be used as a configuration
>	connector, plugging small straps between ground and i8156 line,
>	but how and what for? 
Dunno. Hmm, should look up in the Adaptec 4070 manual, perhaps.
>
>	o About software, I don't care since I always use Minix.
>	(but i beleive that my old AHDI program will not be able to
>	recognize a new disk)

True. But Claus' Brodt driver (CBHD3x) will.
If it now would support the new Atari partitioning sheme (already done
Claus?)...


hase
-- 
Hartmut Semken, Lupsteiner Weg 67, 1000 Berlin 37 hase@netmbx.UUCP
Hi! (Zaphod Beeblebrox)