Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!sugar!peter
From: peter@sugar.hackercorp.com (Peter da Silva)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Filter ON/OFF ; Direct hardware access
Keywords: AUDIO FILTER
Message-ID: <7293@sugar.hackercorp.com>
Date: 18 Dec 90 02:04:25 GMT
References: <50729@eerie.acsu.Buffalo.EDU> <10940@helios.TAMU.EDU> <faheyr.661405562@silver> <10942@helios.TAMU.EDU>
Reply-To: peter@sugar.hackercorp.com (Peter da Silva)
Organization: Sugar Land Unix - Houston
Lines: 31

In article <10942@helios.TAMU.EDU> aaron@stat.tamu.edu (Aaron Hightower) writes:
> In article <faheyr.661405562@silver> faheyr@silver.ucs.indiana.edu (Bob Fahey <NECR0SIS>) writes:
> >filter_on:	move.w	#$7000,$bfe000
> >filter_off:	move.w	#$7002,$bfe000

> It is still possible to write
> small C programs, but it is easier to maintain a scope of your program's size
> when you are using an assembler (IMHO).  

This has nothing to do with C versus Assembler. Try this:

	unsigned short *filter = ((unsigned short *)0xbfe000);
	*filter = 0x7000;
	*filter = 0x7002;

(modulo games with volatile to defeat the optimiser)

You can talk to the hardware directly in C, or assembler. You can use the ROMS
in C, or assembler. If you bypass the ROMS one day someone is going to get
pissed off when their whizz-bang joystick handler doesn't work with your
program.

But for the third time that's got nothing to do with whether your program is in
C or assembler, other than that folks who are into assembler are more likely to
want to play with the silicon directly.

Just make sure you get the address of the joystick registers from the ROMs,
and that you tell them you're stealing a game port.
-- 
Peter da Silva.   `-_-'
<peter@sugar.hackercorp.com>.