f3aml@fyvax2.fy.chalmers.se (03/29/89)
I have a couple of questions regarding the system heap
on the Macintosh. The questions were rised by the following
things. At our department we use the combination of WriteNow2.0
and the MathType DA to write scientific papers. MathType is an
advanced deskaccesory to edit mathematical formulas in a wysiwyg
way. It is absolutely excellent and has simplified our work very much.
When you edit a formula in MathType the program normally shows
it's text in double size to see all details.
That means that to get the the best quality you have to have
all screen fonts installed. I use suitcase 1.2.1 to do this ( I know its
old, I have not upgraded yet). Now to the problem. Sometimes the
program did not use the double sized font to show the text on screen,
even if it is installed, but it scaled a smaller font instead. We also had
some problems with crashes when large formulas were edited, specially
when we tried to change size of the text. When I checked the amount
of free memory with MemoryMonitor I noticed that I only had a couple
of hundred bytes left in the system heap whe MathType was loaded and
some text was entered. When I increased the size of the system
heap ( using Widgets 3.0 which has an option to do that ) the program
used the double size font to show the text and the problem with crashes
was gone. Memory Monitor showed a couple of kbytes free on the system
heap. When I ran Widgets the first time to check the system heap it showed
that it was 80 kbytes larger than normal. After some tests I ended up with
a system heap 160 kbytes larger than normal, and MemoryMonitor showed
a system heap size of 212 kbytes. This has worked fine since then, but it
makes me a little bit curious. How large is it suitable to have the system
heap ? What does take up space on the system heap ? What about Suitcase
installed
fonts vs Systemfile installed fonts. What about DA-s ? What about different
system versions, different hard disk drivers ( I have understood that the
system heap size is read at boot-up time from the disk ) ? What about INIT-s,
CDEV-s, printer drivers etc. I have tried to find somewhere to read about
this, but found nothing, not in Inside Mac, not in any manual I have.
I hope someone can either direct me to a source of information or answer
at least some of my questions. I will try and summarize to the net all
valuable info I get.
Thanks a lot in advance.
Mats Lejon BITNET F3AML@SECTHF51
Physics dept Chalmers univ tech, Sweden