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Path: utzoo!linus!decvax!decwrl!amd!dual!zehntel!ihnp4!ihnss!knudsen
From: knudsen@ihnss.UUCP
Newsgroups: net.micro.6809
Subject: What's in SAM Chips's ROM?
Message-ID: <2272@ihnss.UUCP>
Date: Wed, 24-Oct-84 13:41:07 EST
Article-I.D.: ihnss.2272
Posted: Wed Oct 24 13:41:07 1984
Date-Received: Mon, 29-Oct-84 08:06:03 EST
Organization: AT&T Bell Labs, Naperville, IL
Lines: 15



This is for anyone whose 6809 system includes the 6883 SAM chip, such as
found in CoCos.  Anyone know the purpose/function of the internal ROM's bytes
from about $FFE0 (sorry, I'm at work and Coco is at home) thru $FFF1?
The data are definitely read-only, but don't seem to make any sense either
as 6809 opcodes or as address vectors.  The Motorola books refer to them as
"reserved for system use" (which covers everything above $FF60, and we all
ignore that, don't we), BUT one footnote implies they may be a disk boot,
like for a DOS.  Now wouldn't that be nice...  but it sure doesn't look like
6809 code to me.
	I wonder if we all even have the same data in those bytes.  Could they
be a version or even serial number?  Imagine, copy-protecting software by having
it check the SAM serial #.  If anyone acts interested, I'll post my SAM's
values when I get home.	--mike k.