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From: brian@ut-sally.UUCP (Brian H. Powell)
Newsgroups: comp.sys.mac
Subject: Determining Machine Configuration
Message-ID: <8796@ut-sally.UUCP>
Date: Wed, 19-Aug-87 14:17:52 EDT
Article-I.D.: ut-sally.8796
Posted: Wed Aug 19 14:17:52 1987
Date-Received: Sat, 22-Aug-87 02:44:19 EDT
Organization: U. Texas CS Dept., Austin, Texas
Lines: 32


     I'm trying to discern the difference in my program between the 64K ROMs,
the 128K ROMs and any newer ROMs.  (e.g., the SE ROMs and the II ROMs.)
     I don't have the SysEnvirons glue; apparently that's only for MPW 2.0,
and I'm using LS-C.  I'm not sure I'll be patient enough to wait for Think to
come out with a new version of LS-C which might support SysEnvirons.  I don't
think 2.11 does.
     I had honestly hoped that Apple would live up to their pledge of the way
they would treat the low-memory global ROM85.  (== FFFF for 64K ROMs, 7FFF for
128K ROMs, 3FFF for future ROMs, etc.)  My Mac SE says ROM85==7FFF.  Uhh.
Oops.  Apple goofed on that one.
     So that leaves me with ROMBase+8.  On an SE, it has value 0276.  On the
Mac-Plus it has 0075, on a 64K ROM mac it's 0069 and on an XL 82FF.  What are
the values for a Mac II?  (Can somebody check that out for me?)  The old
Environs call would return (machine_type == 3, ROM version 76) on an SE.
     In case you're wondering, ROM85 is a low-memory global at $28E, and
ROMBase is at $2AE.
     Is it sufficient to assume if Environs returns a machine_type == 1 (the
_byte_ ROMBase+8 == 0) that I'm looking at either a 64K ROM or 128K ROM Mac?
For future reference, does anybody know what the values of ROMBase+8 are
supposed to mean in future machines?

Brian H. Powell
		UUCP:	{ihnp4,seismo,ctvax}!ut-sally!brian
		ARPA:	brian@sally.UTEXAS.EDU

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