bzs@world.std.com (Barry Shein) (05/13/91)
Language: Think/C
System: MacIIfx
I'm trying to use the Vertical Trace Manager in an XCMD and seem to be
getting nowhere. Maybe someone here has done this.
[you could probably stop here and reply if you know something
critical, the rest is detail.]
The application was originally standalone, and the task was called
fine then, so something was correct.
It's all straightforward enough, setting up a pointer to a C routine
as the task, setting the counter, zero phase and so forth, and doing a
VInstall() [returns noErr].
I've even tried putting an exit() into the task just as a last ditch
attempt to see if it's called even once (I am updating the count, but
this would exit on the first call), no dice (there are other ways I'd
know if it was being called, but I figured this should tell me once
and for all, either it exits or it doesn't.) I'm doing a SetUpA5() at
the top (trying to forestall the obvious suggestions.)
Is there some caveat about using the Vertical Trace Manager within an
XCMD that I missed?
The XCMD also accesses the Serial Driver asynchronously
(PBRead(foo,true)), if that makes any difference.
[obviously (?) what I'm trying to do is timeout on no input by waiting
in a GetNextEvent() loop for either more input, my async completion
routine posts an event, or a periodic timeout, which should cause it
to poke the other side to start sending again, but I never get the
timeouts, the VBT never runs.]
It just doesn't seem like it should be all that mysterious, unless
somehow HyperCard itself is somehow undoing my efforts (?) That's one
thing I'm fishing for here.
Thanks.
--
-Barry Shein
Software Tool & Die | bzs@world.std.com | uunet!world!bzs
Purveyors to the Trade | Voice: 617-739-0202 | Login: 617-739-WRLDmandel@vax.anes.tulane.edu (Jeff E Mandel MD MS) (05/13/91)
In article <BZS.91May12205236@world.std.com>, bzs@world.std.com (Barry Shein) writes: > >Language: Think/C >System: MacIIfx > >I'm trying to use the Vertical Trace Manager in an XCMD and seem to be >getting nowhere. Maybe someone here has done this. > I have not played with this, but I recall that the Vertical Retrace Manager has evolved with the move from slotless systems to NuBus systems, so I would test it on a Plus or an SE. I tend to prefer using the Time Manager over Vertical Retrace Manager; if it is not too much trouble, you might try that. The Time Manager is a little closer to the hardware than the VRM (in Mac II class machines), so it might be harder for HC to get in the way. Good luck. Jeff E Mandel MD MS Asst. Professor of Anesthesiology Tulane University School of Medicine New Orleans, LA mandel@vax.anes.tulane.edu