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From: snowdond@r2.cs.man.ac.uk (D.N.Snowdon (MSc PJ))
Newsgroups: comp.sys.amiga.programmer
Subject: playing samples using audio h/w
Keywords: audio DMA
Message-ID: <2325@m1.cs.man.ac.uk>
Date: 22 Mar 91 10:54:04 GMT
Sender: news@cs.man.ac.uk
Organization: Department of Computer Science, University of Manchester UK
Lines: 19


  I'm having a problem playing sound samples by hitting the
hardware directly. The problem is that I set up the registers
for the channel I'm going to use and set audio DMA going
 using 
   move.w #(DMAF_SETCLR!DMAF_MASTER!DMAF_AUD0),dmacon(a0)
as per the h/w manual. The sound starts playing OK.
  If I then stop the sound by turning its DMA off using
  move.w #DMAF_AUD0,dmacon(a0) again as in the h/w manual, 
the sound stops. If I then reload the registers and start
DMA going the sound I get is the remains of the first sample
(assuming I stopped it before it had finished playing
completely). The h/w manual does say that if you stop and
start DMA over a short period then this can happen but there
is actually quite a long delay between turning off DMA for
the first sample and turning it on for the second.
  Can anyone shed any light on this?

             Dave   ( snowdond@uk.ac.man.cs )