From: varobert AT colba DOT net
Message-Id: <3.0.32.19990807111759.007df3f0@mail.colba.net>
X-Sender: varobert AT mail DOT colba DOT net
X-Mailer: Windows Eudora Pro Version 3.0 (32)
Date: Sat, 07 Aug 1999 11:18:17 -0400
To: djgpp AT delorie DOT com
Subject: Re: Order of Operations (SB Question)
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Reply-To: djgpp AT delorie DOT com

Did the memory you allocate reside under the 1MB barrier ? it has to be for
DMA transfers to occur. I think it also has to be segment-aligned
(16-bytes) (not sure about this).

I recommend you also check out the source for Allegro: find out how they do
things; it can always help.


At 05:55 PM 8/6/99 -0400, you wrote:
>Okay I have written some code to play some SFX with the Sound Blaster. 
>The problem is that when I try to write anything to the sound blaster
>the porgram crashes.  In order here is what I do:
>
> - Search for SoundBlaster Properties (ie IRQ, DMA, DMA16, BASE IO)
> - Init using previous information (makes some variables containing
>writeports and stuff like that
> - Install a Handler (i'm really not sure what this is for but every
>sample I looked at had it so far it only contains code that acknowledges
>the writes (or something to this level))
> - Initialize a buffer of 2048 bytes in size (this is the mixing block)
> - Start the DAC (turn on Speaker, make sure SB knows some infomration
>about the buffer)
> - Open a RAW file and dumb 2048 bytes of information into the buffer
> - DeInit (Stop DAC, free buffer, uninstall handler)
>
>The program compiles fine, and I'm pretty sure I have the right ports
>and stuff like that, but then the Program GPFs at the part where I open
>a RAW file for reading.  
>
>Note that I only initialize 2048 because I want to mix sounds later on
>(a la SMIX library by Ethan Brodsky). 
>Note 2:  And please don't anybody tell me to abandon this project and go
>use the Allegro Library.  I am aware of the libraries greatness.  But my
>purpose is to learn *how* to do this, not how to program with Allegro!
>
>PS. What do these functions do?  (They wheren't in the libC help)
>

>_farsetsel()
>_fargetsel()
>_farnspokeb()

they're under _far*

>
>

- GodOfWar
In the world of computers, things tend to become faster, smaller and
cheaper with time. Does that mean that Microsoft invented time travel ?