Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!metaphor!neuromancer!djh
From: djh@neuromancer.metaphor.com (Dallas J. Hodgson)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Micro Timing Critical sections HELP!
Message-ID: <1447@metaphor.Metaphor.COM>
Date: 20 Sep 90 18:39:20 GMT
References: <4934@uqcspe.cs.uq.oz.au>
Sender: news@metaphor.Metaphor.COM
Reply-To: djh@neuromancer.metaphor.com (Dallas J. Hodgson)
Organization: Metaphor Computer Systems, Mountain View, CA
Lines: 35

In article <4934@uqcspe.cs.uq.oz.au> thyssen@batserver.cs.uq.oz.au writes:
>
>
<stuff about timing 'C' code deleted>

>I am using Disable() during the timed period to stop other tasks. 
>
>QUESTIONS :-
> 1)  What is the differance bettween Disable-Enable
>   and Forbid-Permit exec library calls?
> 2)  How do you blank the screen?
> 3)  Is there any other interupts which can be disabled? How?
> 4)  Under the above can memory still be allocated/deallocated - Important?
> 5)  Any other comments.
>

1) Disable() turns off interrupts. Forbid() disables task switching.
2) Throw up a 1-bitplane black screen. Or, disable video DMA with
   the OFF_DISPLAY (sp?) macro.
3) Sure, you can disable anything you want. I think you'll understand more
   if you read:
     a) The Amiga Hardware Reference Manual
     b) The Amiga Rom Kernel Manual: Exec
     c) The Guru's Guide to the Amiga : Interrupts, by Carl Sassenrath
4) Possibly, but I'd warn against it. Could break in the future.

Nice sig.
+----------------------------------------------------------------------------+
| Dallas J. Hodgson               |     "This here's the wattle,             |
| Metaphor Computer Systems       |      It's the emblem of our land.        |
| Mountain View, Ca.              |      You can put it in a bottle,         |
| USENET : djh@metaphor.com       |      You can hold it in your hand."      |
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