From nrodriguez@pipeline.com Sun May 08 10:14:41 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!pipeline!nrodriguez From: nrodriguez@pipeline.com (Natalia Rodríguez) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994May08.101441.5414@pipeline.com> Date: Sun, 08 May 1994 10:14:41 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com 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. -- Natalia Rodríguez | nrodriguez@pipeline.com PGP Key fingerprint: F761 225A 7FC6 17CA "Keep the channels open." From tmoreau@panix.com Mon May 09 23:47:41 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!panix!tmoreau From: tmoreau@panix.com (Thiago Moreau) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994May09.234741.5257@panix.com> Date: Mon, 09 May 1994 23:47:41 GMT References: <1994May08.101441.5414@pipeline.com> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1994May08.101441.5414@pipeline.com>, nrodriguez@pipeline.com (Natalia Rodríguez) 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. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Thiago Moreau Zyxel U-1496E @ 33,600 bps "In theory there is no difference between theory and practice." From tpetrov@kiae.su Tue May 10 07:32:41 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!kiae!tpetrov From: tpetrov@kiae.su (Thiago Petrov) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994May10.073241.6636@kiae.su> Date: Tue, 10 May 1994 07:32:41 GMT References: <1994May08.101441.5414@pipeline.com> <1994May09.234741.5257@panix.com> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: Netscape 1.1N Lines: 9 In article <1994May09.234741.5257@panix.com>, tmoreau@panix.com (Thiago Moreau) 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Thiago Petrov *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From jjohansson@uu.net Wed May 11 04:56:41 1994 Path: ashpoly!cascade!bigsur!uu!jjohansson From: jjohansson@uu.net (Jen Johansson) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994May11.045641.4938@uu.net> Date: Wed, 11 May 1994 04:56:41 GMT References: <1994May08.101441.5414@pipeline.com> <1994May09.234741.5257@panix.com> <1994May10.073241.6636@kiae.su> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994May10.073241.6636@kiae.su>, tpetrov@kiae.su (Thiago Petrov) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Jen Johansson | jjohansson@uu.net PGP Key fingerprint: 4172 6F2E C002 1F51 "Keep the channels open." From bcampbell@kiae.su Wed May 11 15:26:41 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kiae!bcampbell From: bcampbell@kiae.su (Bruno Campbell) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994May11.152641.4882@kiae.su> Date: Wed, 11 May 1994 15:26:41 GMT References: <1994May08.101441.5414@pipeline.com> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994May08.101441.5414@pipeline.com>, nrodriguez@pipeline.com (Natalia Rodríguez) 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. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- === Bruno Campbell === Dept of Electrical Engineering, Kurchatov Institute of Atomic Energy, Moscow "In theory there is no difference between theory and practice."