From mmoreno@pacbell.net Sat Aug 13 19:23:53 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!pacbell!mmoreno From: mmoreno@pacbell.net (Marisol Moreno) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug13.192353.3376@pacbell.net> Date: Sat, 13 Aug 1994 19:23:53 GMT Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: Netscape 1.1N Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Marisol Moreno Zyxel U-1496E @ 9600 Telebit bps "Hold for relay." From epark@hanse.de Sun Aug 14 03:24:53 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!hanse!epark From: epark@hanse.de (Elaine Park) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug14.032453.5101@hanse.de> Date: Sun, 14 Aug 1994 03:24:53 GMT References: <1994Aug13.192353.3376@pacbell.net> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Aug13.192353.3376@pacbell.net>, mmoreno@pacbell.net (Marisol Moreno) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Elaine Park *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From eweber@hanse.de Sun Aug 14 14:16:53 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!hanse!eweber From: eweber@hanse.de (Emi Weber) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug14.141653.6469@hanse.de> Date: Sun, 14 Aug 1994 14:16:53 GMT References: <1994Aug13.192353.3376@pacbell.net> <1994Aug14.032453.5101@hanse.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1994Aug14.032453.5101@hanse.de>, epark@hanse.de (Elaine Park) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Emi Weber Tape trading list upon request. SASE required for international mail. From mhughes@pacbell.net Mon Aug 15 04:32:53 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!pacbell!mhughes From: mhughes@pacbell.net (Min-jun Hughes) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug15.043253.7735@pacbell.net> Date: Mon, 15 Aug 1994 04:32:53 GMT References: <1994Aug13.192353.3376@pacbell.net> <1994Aug14.032453.5101@hanse.de> <1994Aug14.141653.6469@hanse.de> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Aug14.141653.6469@hanse.de>, eweber@hanse.de (Emi Weber) writes: > PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- === Min-jun Hughes === Dept of Electrical Engineering, Pacific Bell Internet Services "When every node is whole, the channel opens."