Xref: utzoo comp.sys.mac:43401 comp.sys.mac.programmer:10857
Path: utzoo!attcan!uunet!mailrus!purdue!bu-cs!dartvax!eleazar.dartmouth.edu!jskuskin
From: jskuskin@eleazar.dartmouth.edu (Jeffrey Kuskin)
Newsgroups: comp.sys.mac,comp.sys.mac.programmer
Subject: Re: System Heap tirade (was Re: Resizing the System Heap)
Message-ID: <17642@dartvax.Dartmouth.EDU>
Date: 3 Dec 89 20:14:09 GMT
References: <1195@kl-cs.UUCP> <24663@cup.portal.com> <1989Dec3.181013.8659@caen.engin.umich.edu>
Sender: news@dartvax.Dartmouth.EDU
Reply-To: jskuskin@eleazar.dartmouth.edu (Jeffrey Kuskin)
Followup-To: comp.sys.mac
Organization: Dartmouth College, Hanover, NH
Lines: 24

In article <1989Dec3.181013.8659@caen.engin.umich.edu> billkatt@mondo.engin.umich.edu (billkatt) writes:
>   [stuff deleted]
>
>For the adventurous out there, you can try adding sysz resources to the INITs
>that you are having trouble with.
>
You really don't have to be "adventurous" at all.  I had the same problem
while writing an interrupt handler -- it needed a 40K block of storage in
the system heap.  My solution was to create a "dummy" INIT which consisted
of:
    1)  A 'sysz' resource specifying how much free space was required.
        (See IM Vols. 4 and 5 for details).
 
    2)  An 'INIT' resource consisting of a single RTS instruction.

Ths INIT was, of course, executed at boot time.  Then, when the user
went to install the interrupt handler, the 40K block was usually
available (the handler could not be installed by the INIT for reasons
I won't go into.)
 
So... if you need system heap space, don't hesitate to use a sysz
resource, either in a dummy INIT as I did, or as part of an actual INIT.
 
-- Jeff Kuskin, Dartmouth College