Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!oliveb!pyramid!cbmvax!sterling
From: sterling@cbmvax.UUCP (Rick Sterling QA)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Is 29 Khz really the fastest audio playback rate?
Message-ID: <3778@cbmvax.UUCP>
Date: 16 May 88 14:12:55 GMT
References: <8805151814.AA08523@cory.Berkeley.EDU>
Reply-To: sterling@cbmvax.UUCP (Rick Sterling QA)
Organization: Commodore Technology, West Chester, PA
Lines: 27

In article <8805151814.AA08523@cory.Berkeley.EDU> dillon@CORY.BERKELEY.EDU (Matt Dillon) writes:
> 
> >The Amiga Hardware Reference Manual says that 29 KHz is the maximum
> >playback rate for audio samples.  Is this for sure true and are there
> >any sorts of software-achievable hacks to exceed it?
> >-- 
> >"Now here's something you're really going to like!" -- Rocket J. Squirrel
> >...!{bellcore!tness1,uunet!nuchat}!sugar!karl, Unix BBS (713) 438-5018
> 	
> 	From what I understand, 31Khz is possible, but the hardware was
> really designed for 28.867Khz to 'save buffers'.  The hardware manual
> states that the audio DMA cannot keep up with the rate at higher frequencies.
> 
> 				-Matt

 This is true for DMA controlled audio playback only. If you are willing to
 take direct control of the D/A's with the CPU and some machine code you can
 get output up in the megahertz range. ( You'd have to disable the built in
 anti-aliasing low-pass filters though. )

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   Rick Sterling             COMMODORE AMIGA TEST ENGINEERING
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