Path: utzoo!utgpu!watserv1!watmath!att!rutgers!usc!zaphod.mps.ohio-state.edu!rpi!crdgw1!ge-dab!tarpit!bilver!alex
From: alex@bilver.UUCP (Alex Matulich)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Bypassing the Audio Filter
Message-ID: <826@bilver.UUCP>
Date: 20 Jul 90 20:20:45 GMT
References: <90195.001845L98CC@CUNYVM.BITNET> <3519@crash.cts.com>
Reply-To: alex@bilver.UUCP (Alex Matulich)
Organization: W. J. Vermillion, Winter Park, FL
Lines: 26

In article <3519@crash.cts.com> jcs@crash.cts.com (John Schultz) writes:
>In article <90195.001845L98CC@CUNYVM.BITNET> L98CC@CUNYVM writes:
>>   I want to write a program to turn off the hi-frequency filter on A500.
>>I do know that setting a certain bit in certain address will turn it off.
>>What is that address and bit?  But even better, is there a system call I can
>
>  In C:
>  unsigned char * filter = (unsigned char *)0xBFE001;
>     *filter = (*filter) & 0xfe; /* Turn off */
>     *filter = (*filter) | 1;    /* Turn on */

No, NO!  You only need to switch the second bit!

For example, to toggle the bit on and off, you would say,

*filter ^= 2;

You shouldn't mess with the other bits... you don't know what they
might be for!


-- 
     ///  Alex Matulich
    ///  Unicorn Research Corp, 4621 N Landmark Dr, Orlando, FL 32817
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