From rduarte@cam.ac.uk Sun Jan 15 01:52:03 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!cam!rduarte From: rduarte@cam.ac.uk (Raj Duarte) Newsgroups: comp.sys.m68k Subject: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan15.015203.9661@cam.ac.uk> Date: Sun, 15 Jan 1995 01:52:03 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 11 Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- === Raj Duarte === Dept of Electrical Engineering, University of Cambridge Computer Laboratory "Hardware is temporary. The signal survives." From dnakamura@unam.mx Mon Jan 16 09:58:03 1995 Path: ashpoly!cascade!transat!ukc!fennimore!unam!dnakamura From: dnakamura@unam.mx (Dave Nakamura) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan16.095803.9170@unam.mx> Date: Mon, 16 Jan 1995 09:58:03 GMT References: <1995Jan15.015203.9661@cam.ac.uk> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jan15.015203.9661@cam.ac.uk>, rduarte@cam.ac.uk (Raj Duarte) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. > 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. -- Dave Nakamura Tape trading list upon request. SASE required for international mail. From ktakahashi@netcom.com Tue Jan 17 00:00:03 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!netcom!ktakahashi From: ktakahashi@netcom.com (Katrin Takahashi) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan17.000003.6991@netcom.com> Date: Tue, 17 Jan 1995 00:00:03 GMT References: <1995Jan15.015203.9661@cam.ac.uk> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jan15.015203.9661@cam.ac.uk>, rduarte@cam.ac.uk (Raj Duarte) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Katrin Takahashi *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0