[comp.sys.mac.programmer] Passing the buck: DA crashes my THINK App, but not DA Handler. Que?

gft_robert@gsbacd.uchicago.edu (04/14/90)

I'm writing a simple App in THINK Pascal and wanted to test its DA handling. 
When I load the DA "dCAD Calculator" into the App's heap (I'm running under
MultiFinder, so I do this by holding down the option key while loading the DA),
and I make it calculate an overflow value -- like e to the 99999th power --, my
App "quits unexpectedly" with error 16 (Floating Point Error).  (The app seems
to handle other DA's fine).

Not too mysterious, huh?  But if the DA is loaded into the DA Handler, the DA
can deal with this sort of overflow value fine, and puts up an infinity sign in
its answer box and keeps on running.

Am I missing something obvious?  I can see why a crashing DA would make my app
crash, but I don't see why the DA can handle the overflow while running in the
DA handler -- and thus doesn't crash -- , and why it can't in my App.

Any help much appreciated, as I'm mucho perplexed.


Robert
 
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