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From: koster@cory.Berkeley.EDU (Kevin Oster)
Newsgroups: comp.sys.amiga.tech,comp.sys.amiga
Subject: What is the checksum used for the Amiga's track & sector information
Keywords: Checksum, Disk, Sector
Message-ID: <3845@pasteur.Berkeley.Edu>
Date: 9 Jun 88 01:17:57 GMT
Sender: news@pasteur.Berkeley.Edu
Reply-To: koster@cory.Berkeley.EDU.UUCP (Kevin Oster)
Organization: University of California, Berkeley
Lines: 11


   This is a very technical question. I am going to the disk hardware directly
(Thanks for all the help on getting that going...It was the disk.resource that
solved it.) Anyway, I want to write a format routine and I don't know enough
about the checksum.
   The RKM volume 2 tells a little about the format. It says there are two
32 bit checksums, one for the header information and one for the data area.
How do I compute them? These checksums are on the raw data after MFM decoding,
even lower level than trackdisk. Also is there anything special about the
$4489 matchword? Couldn't it be found by chance in a sector's data area?
($4489 is the MFM encoded version of $A1)