Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!ut-emx!ccwf.cc.utexas.edu From: lshaw@ccwf.cc.utexas.edu (logan shaw) Newsgroups: comp.sys.amiga.tech Subject: Re: Filter ON/OFF Keywords: AUDIO FILTER Message-ID: <41560@ut-emx.uucp> Date: 18 Dec 90 00:32:55 GMT References: <50729@eerie.acsu.Buffalo.EDU> <10940@helios.TAMU.EDU> Sender: news@ut-emx.uucp Reply-To: lshaw@ccwf.cc.utexas.edu (logan shaw) Organization: The University of Texas at Austin Lines: 36 In article faheyr@silver.ucs.indiana.edu (Bob Fahey ) writes: >aaron@stat.tamu.edu (Aaron Hightower) writes: >Hmm... I'll probably regret posting this, since the last time I did so, >I got flamed to hell. (I am talking about reading/writing registers directly). >It seems that a few C programmers would rather write a large quantity of code >instead of just dealing with the info at the the source, i.e. registers. It's not that we're C programmers, it's that we're trying to do it correctly, so it doesn't break later on. You can write incorrectly in C, and (believe it or not) you can write *correctly* in assembly as well. Poking around at the hardware when there is an operating-system interface is simply not acceptable. I have done it before, and I've seen it break. You can't go breaking the rules and expect your software to work on new machines like the 3000. Your code may work faster in some cases, but in some cases it won't work at all. >Anyway, Here's how I have done it (not saying it is CORRECT, but it works >nonetheless) ;-) >filter_on: move.w #$7000,$bfe000 >filter_off: move.w #$7002,$bfe000 Written incorrectly in C: #define FILTER_ON ( *((short *)0xbfe000) = 0x7000 ) #define FILTER_OFF ( *((short *)0xbfe000) = 0x7002 ) >| ///| a.k.a. NECR0SIS faheyr@silver.ucs.indiana.edu -or- | >| \\\///_| faheyr@rose.ucs.indiana.edu | >| \XX/ | M I G A "'Ere long done do does did..." - The Smiths | >| "...life is seen through the eyes of a dog..." - Skinny Puppy | -- =----------------Logan-Shaw---(lshaw@ccwf.cc.utexas.edu)----------------= "Trust in the Lord with all thine heart, and lean not on thine own understanding. In all thy ways acknowledge Him and he shall direct thy paths" - Proverbs 3:5-6