Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uupsi!sunic!news.funet.fi!funic!santra!hila.hut.fi!jmunkki
From: jmunkki@hila.hut.fi (Juri Munkki)
Newsgroups: comp.sys.mac.programmer
Subject: Video Card Driver + Sound Manager Question
Message-ID: <1991Mar24.173747.867@santra.uucp>
Date: 24 Mar 91 17:37:47 GMT
Sender: news@santra.uucp (Cnews - USENET news system)
Reply-To: jmunkki@hila.hut.fi (Juri Munkki)
Organization: Helsinki University of Technology, FINLAND
Lines: 46

Here's a hard question for those who really know what is going on with
video cards:

I'm having trouble with the 8.24 video card, because it apparently disables
interrupts (including the 60 Hz VBL interrupt) while a SetEntries is executing.
I dug up the sample video card driver sources from apple.com and found the
following comment:

;  This routine can optionally be implemented to execute asynchronously, by 
;  posting the CLUT change request in a table that is loaded as part of the
;  slot interrupt handler.  The Macintosh will NOT call this Control call 
;  with the async variant of the trap, rather, the SetEntries call executes as
;  a normal Control call, and delays it's hardware activity until VBL.
;  In doing this, a few extra rules must be followed:
;
;	1) The driver should implement KillIO (see above)
;	2) If SetEntries is entered while the interrupt level is
;	   non-zero, it should write immediately to the CLUT hardware.


If I understand this correctly, it says that I can install my own video
card VBL routine that will then make a _Control call to change the clut
on the video card.

Right now my 60 Hz VBL task is not called regularly, if I call SetEntries.

I would appreciate it, if someone clarified the comment above and told me
what it means exactly. I know I will need to install a video card VBL task
that changes the clut, if I use the 3D LC shutter glasses.

------

My second question is:

	Why is there no documentation for the 6.07 sound manager on apple.com?
	Either remove the 6.02 documents or replace them with something that is
	more up to date.

I'm still using the old sound driver, because the sound manager has been so
buggy. I guess 6.07 has changed this a bit, so I would like to start using
the new sound manager, if possible.

   ____________________________________________________________________________
  / Juri Munkki	    /  Helsinki University of Technology   /  Wind  / Project /
 / jmunkki@hut.fi  /  Computing Center Macintosh Support  /  Surf  /  STORM  /
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