From tperez@cmu.edu Sat Apr 15 15:37:47 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cmu!tperez From: tperez@cmu.edu (Tyler Pérez) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr15.153747.3115@cmu.edu> Date: Sat, 15 Apr 1995 15:37:47 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. 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. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Tyler Pérez "When every node is whole, the channel opens." Decstation 5000/200 / SunOS 4.1.4 From nmoreno@earthlink.net Sun Apr 16 06:15:47 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!earthlink!nmoreno From: nmoreno@earthlink.net (Nadia Moreno) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr16.061547.6858@earthlink.net> Date: Sun, 16 Apr 1995 06:15:47 GMT References: <1995Apr15.153747.3115@cmu.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Apr15.153747.3115@cmu.edu>, tperez@cmu.edu (Tyler Pérez) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Nadia Moreno | nmoreno@earthlink.net PGP Key fingerprint: D617 D88F F098 107F "Keep the channels open." From tnilsson@earthlink.net Sun Apr 16 14:27:47 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!tnilsson From: tnilsson@earthlink.net (Tobias Nilsson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr16.142747.8346@earthlink.net> Date: Sun, 16 Apr 1995 14:27:47 GMT References: <1995Apr15.153747.3115@cmu.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Apr15.153747.3115@cmu.edu>, tperez@cmu.edu (Tyler Pérez) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Tobias Nilsson SupraFAXModem 28.8 @ 14,400 bps "Tape doesn't lie at 02:14. Ears do."