Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!uwmcsd1!ig!agate!ucbvax!CORY.BERKELEY.EDU!dillon
From: dillon@CORY.BERKELEY.EDU (Matt Dillon)
Newsgroups: comp.sys.amiga
Subject: Re: Request to Commodore (Bad Blocks)
Message-ID: <8809211835.AA11980@cory.Berkeley.EDU>
Date: 21 Sep 88 18:35:50 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 17

: -------------------------------------------------------------------
: * DO NOT CHANGE THE WAY YOU READ.  ONLY CHANGE THE WAY YOU WRITE. *
: -------------------------------------------------------------------
:Therefore READS TAKE THE SAME AMOUNT OF TIME whether the writes are
:decoupled from the index pulse or not.

	The problem is that there is no automatic index-start-dma thing
in hardware... i.e., you get an interrupt on the index and the interrupt
handler must then start the DMA.

	This means that while the track will be synced pretty close to 
the index, it won't be exact, and the system would have to map out, say,
the sector before and after the bad one to be sure.

	Apart from that, it's a handy solution.

				-Matt