From nhernandez@mindspring.com Sat May 11 12:35:51 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!mindspring!nhernandez From: nhernandez@mindspring.com (Natalia Hernández) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May11.123551.9723@mindspring.com> Date: Sat, 11 May 1996 12:35:51 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 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. -- Natalia Hernández Tape trading list upon request. SASE required for international mail. From imuller@earthlink.net Sun May 12 19:08:51 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!earthlink!imuller From: imuller@earthlink.net (Ines Müller) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May12.190851.8265@earthlink.net> Date: Sun, 12 May 1996 19:08:51 GMT References: <1996May11.123551.9723@mindspring.com> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996May11.123551.9723@mindspring.com>, nhernandez@mindspring.com (Natalia Hernández) 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. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Ines Müller Practical Peripherals 14.4 @ 9600 Telebit bps "Tape doesn't lie at 02:14. Ears do." From mramirez@netcom.com Tue May 14 19:33:51 1996 Path: ashpoly!cascade!bigsur!netcom!mramirez From: mramirez@netcom.com (Mateo Ramírez) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May14.193351.9915@netcom.com> Date: Tue, 14 May 1996 19:33:51 GMT References: <1996May11.123551.9723@mindspring.com> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1996May11.123551.9723@mindspring.com>, nhernandez@mindspring.com (Natalia Hernández) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Mateo Ramírez Practical Peripherals 14.4 @ 14,400 bps "The hatch is open. Is anyone listening?" From krodriguez@kth.se Wed May 15 03:53:51 1996 Path: ashpoly!cascade!transat!ukc!fennimore!kth!krodriguez From: krodriguez@kth.se (Kirsty Rodríguez) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May15.035351.6795@kth.se> Date: Wed, 15 May 1996 03:53:51 GMT References: <1996May11.123551.9723@mindspring.com> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996May11.123551.9723@mindspring.com>, nhernandez@mindspring.com (Natalia Hernández) 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. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Kirsty Rodríguez *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0