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From: wdao@castor.usc.edu (Walter Dao)
Newsgroups: comp.sys.amiga.tech
Subject: amiga disk drives ...
Message-ID: <4285@merlin.usc.edu>
Date: 4 Jul 89 06:37:10 GMT
Sender: news@merlin.usc.edu
Reply-To: wdao@castor.usc.edu (Walter Dao)
Organization: University of Southern California, Los Angeles, CA
Lines: 24

The amiga disk drive as any other drive can only write a given number
of WORDS (2 bytes) on any single track. On my drive I can write and can only
write about $31d8 (+/- 2) bytes. (they are composing the raw MFM bytes of the
sectors, headers and gap .)
Now I have encountered disks written by other amiga computers which had 
more bytes on them (the abacus disk had 320a bytes on track) or less bytes
on disk (like Thexder which had 30ca or something ... (forgot)).

now my question : how can I slow/speed up the motor (?) write spead (?) 
of my disk drive so that I can have more/less bytes storable on a track

I have tried to play with the PRECOMP stuff but that didnt help, I was still
stuck with being able to only write 31d8 bytes on a track. 
I even tried to alter the data written by the DMA (like writting only
00 on a full track , then writing less than 31d8 bytes on that same track.
(lets say 3000 bytes) but I still got a track of 31d8 bytes storable on it..

any Hardware modification is definitely out of the question. 
I have read and reread the HArdware manual but could find any lead.

anyway ... I am waiting for any replies ... 

	
			8-#