From jmartinez@ox.ac.uk Mon Dec 11 13:39:38 1995 Path: ashpoly!cascade!bigsur!ox!jmartinez From: jmartinez@ox.ac.uk (Jen Martínez) Newsgroups: comp.sys.m68k Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec11.133938.8857@ox.ac.uk> Date: Mon, 11 Dec 1995 13:39:38 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: TIN [version 1.2 PL2] 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. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Jen Martínez -- Oxford University Computing Laboratory "In theory there is no difference between theory and practice." From dfischer@cern.ch Wed Dec 13 04:37:38 1995 Path: ashpoly!cascade!transat!ukc!fennimore!cern!dfischer From: dfischer@cern.ch (Dong-hyun Fischer) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec13.043738.6798@cern.ch> Date: Wed, 13 Dec 1995 04:37:38 GMT References: <1995Dec11.133938.8857@ox.ac.uk> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Dec11.133938.8857@ox.ac.uk>, jmartinez@ox.ac.uk (Jen Martínez) 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. -- === Dong-hyun Fischer === Dept of Electrical Engineering, European Laboratory for Particle Physics, Geneva "Tape doesn't lie at 02:14. Ears do." From mreyes@delphi.com Wed Dec 13 17:17:38 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!delphi!mreyes From: mreyes@delphi.com (Min-jun Reyes) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec13.171738.1040@delphi.com> Date: Wed, 13 Dec 1995 17:17:38 GMT References: <1995Dec11.133938.8857@ox.ac.uk> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Dec11.133938.8857@ox.ac.uk>, jmartinez@ox.ac.uk (Jen Martínez) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. PGP Public key available via finger or upon request. -- Min-jun Reyes *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0 From dsouza@panix.com Fri Dec 15 04:19:38 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!panix!dsouza From: dsouza@panix.com (Diego Souza) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec15.041938.8797@panix.com> Date: Fri, 15 Dec 1995 04:19:38 GMT References: <1995Dec11.133938.8857@ox.ac.uk> <1995Dec13.043738.6798@cern.ch> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Dec13.043738.6798@cern.ch>, dfischer@cern.ch (Dong-hyun Fischer) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Top-posters will be placed in my ~/.killfile without notice. -- Diego Souza -- Public Access Unix of New York "We don't sign stars. We build them."