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From: mjg@ecsvax.UUCP (Michael Gingell)
Newsgroups: net.micro.atari,net.micro.amiga
Subject: Re: Amiga sound capabilities
Message-ID: <904@ecsvax.UUCP>
Date: Fri, 13-Dec-85 08:50:56 EST
Article-I.D.: ecsvax.904
Posted: Fri Dec 13 08:50:56 1985
Date-Received: Sun, 15-Dec-85 00:23:53 EST
References: <8512062142.AA07057@ucbvax.berkeley.edu> <977@cadovax.UUCP> <267@sdcarl.UUCP>
Organization: North Carolina Educational Computing Service
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Xref: watmath net.micro.atari:1973 net.micro.amiga:1115

> 
> How does the Amiga sample sound??  I have heard this many, many times, yet no-
> one has ever mentioned an ADC in the machine, only an 8-bit DAC.  (By the way,
> does this DAC have the proper anti-aliasing filters?)  
> 
> 	thomas r. erbe
The Amiga does not have any built in analog to digital converter
for digitizing sound. It only has digital to analog converters - two
to give stereo capability, each is 8 bit linear with a 4 bit (I think)
scaling volume control. There are proper anti aliasing filters which
cut off starting at around 7 kHz. Sound samples stored in memory can
be played through the D/As using DMA completely transparent to and
without slowing down the 68000. The Amigas bus operates at 14.4 MHz
half of which is used by the 68000 (i.e. at 7.2 MHz) and half by the
coprocessors which do DMA for video, disk I.O, sound etc. If things
get really busy then the video coproccessors can steal extra time
and slow down the 68K.

As far as I know digitizing sound must be done by an external device.

Hope this helps.  Mike Gingell,  ....decvax!mcnc!ecsvax!mjg
> 	{ucbvax,ihnp4,akgua,hplabs,sdcsvax}!sdcarl!tre