Path: utzoo!attcan!uunet!zephyr.ens.tek.com!tektronix!gvgpsa!gvgpvd!andyp
From: andyp@gvgpvd.GVG.TEK.COM (Andy Peterman)
Newsgroups: comp.sys.mac.programmer
Subject: Re: _OSDispatch
Keywords: Multifinder
Message-ID: <1333@gvgpvd.GVG.TEK.COM>
Date: 21 Nov 89 06:16:27 GMT
References: <306@dbase.UUCP>
Reply-To: andyp@gvgpvd.GVG.TEK.COM (Andy Peterman)
Organization: Grass Valley Group, Inc.; PVD
Lines: 22

In article <306@dbase.UUCP> awd@dbase.UUCP (Alastair Dallas) writes:
>Can anyone tell me what OSDispatch is supposed to do?  I'm tracing
>through some code and I'm forced to guess what's going on behind
>this closed door.  I gather from tech note #180's brief mention
>that it has something to do with MultiFinder and memory allocation.
>It takes an int selector code < $20 (it seems) and I found a table
>of addresses followed by two shorts that might have been size of
>parameter, size of return value.

The _OSDispatch routines are system calls to MultiFinder.  Some of these
are documented in the Programmer's Guide to MultiFinder available from
APDA.  These functions (the ones that Apple admits to) deal with memory
allocation from the MultiFinder memory.  There are others that are
used internally by Apple products (Finder and Sade, for example) that
can access information about all applications that are running under
MultiFinder.  System 7.0 preliminary documentation hints that these will
be available then (meaning they will finally be documented).  If you can't
wait for System 7.0, check out the article in Autumn '89 MacTech
Quarterly (page 25).  This has a totally unofficial explanation of many
of these other functions.  Use at your own risk!

	Andy Peterman