Path: utzoo!attcan!uunet!ncrlnk!ncr-sd!hp-sdd!hplabs!well!brecher
From: brecher@well.UUCP (Steve Brecher)
Newsgroups: comp.sys.mac
Subject: Re: Suitcase II Upgrade  (Revisited)
Keywords: Suitcase II, upgrade,  Pyro! 3.0
Message-ID: <7655@well.UUCP>
Date: 14 Nov 88 23:24:10 GMT
References: <10707@dartvax.Dartmouth.EDU> <67998@felix.UUCP> <7576@well.UUCP> <68503@felix.UUCP>
Reply-To: brecher@well.UUCP (Steve Brecher)
Organization: Software Supply, Sunnyvale, CA
Lines: 48


In article <68503@felix.UUCP> kehr@felix.UUCP (Shirley Kehr) writes:

> Wouldn't it be great if you could have a second monitor of some kind that
> showed you how your actions affect memory usage?

Under MultiFinder, the "About the Finder..." window gives some indication
of memory usage on a continuous basis.  There are also DAs that do this;
for example, the "Memory" DA shows the amount of free space in the
application and system heaps (and on the startup disk).

> Steve Brecher (author of Suitcase) along with one or two Apple programmers
> who answered questions in MacUser or MacWorld both say that you use the
> memory only when you use the resource. I presume that when I use two fonts
> Times and Courier, I have used two resources. 
> 
> I recently took out all but one or two small point sizes of fonts. Does that
> make a difference in the size of the resource I've used. (In other words,
> my documents use several sizes of Times, but I've only installed a small
> (10 pt) size. Am I using less memory by making the system generate the 
> larger sizes. If it's all the same, I'll put the larger point sizes back in
> the system file and have a better looking display.

Yes and no.  If you make the system scale one point size, you won't be using
RAM for the FONT or NFNT resources for the other sizes.  But those resources
only have to be in RAM at the time their characters are being drawn on the
screen.  At other times, if such a resource was previously loaded into RAM,
and the system needs more RAM than is free, the previously-loaded resource
will be cleared from RAM; when it is next needed, it will be read from
disk again.  Thus for such resources, which are called "purgeable," the
effect of reduced RAM is on speed of operation because of the necessity
of re-reading them from disk.  However, for larger point sizes, the
resources are larger; thus if only one FONT or NFNT were to be in RAM at
a time, it would be better from a RAM-consumption standpoint if it were
for a small point size.  I do not know what, if any, RAM is required by
the Font Manager and/or QuickDraw in the process of performing size scaling.

Digression: All screen font resources should be marked as purgeable by
their vendors, although not all actually are.  For example, Adobe FONDs
are not marked as purgeable. (This isn't be relevant to your question about
removing certain sizes.)  Note that Suitcase II, of which I am author, makes
it appear to the system as if all FONDs, FONTs, and NFNTs are marked purgeable
even if they are not in fact so marked.  In (even more) technical terms, with
Suitcase II installed the resPurgeable bit of FOND, FONT, and NFNT resources
is in effect always set, even if it's not actually set in the resource map
on the disk.  If the bit was not set in the screen font disk file, it will
become set in the file if any software which loaded the resource subsequently
causes the file's resource map to be written back to disk.