From jnilsson@pacbell.net Sun Jul 03 20:57:56 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!pacbell!jnilsson From: jnilsson@pacbell.net (Julien Nilsson) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul03.205756.3365@pacbell.net> Date: Sun, 03 Jul 1994 20:57:56 GMT Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: NewsWatcher 2.0b24 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. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Julien Nilsson Hayes Optima 288 @ 19,200 bps "Measuring a record you own is listening, not piracy." From jpetrov@mit.edu Tue Jul 05 01:10:56 1994 Path: ashpoly!cascade!brgate!saturno!mit!jpetrov From: jpetrov@mit.edu (Jens Petrov) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul05.011056.2293@mit.edu> Date: Tue, 05 Jul 1994 01:10:56 GMT References: <1994Jul03.205756.3365@pacbell.net> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1994Jul03.205756.3365@pacbell.net>, jnilsson@pacbell.net (Julien Nilsson) 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! If you are posting from AOL, please read RFC 1036 before posting again. -- Jens Petrov "5 sigma is a discovery. 7 is a question." Commodore Amiga 500 (1MB OCS) / AmigaOS 3.1 From apark@uu.net Wed Jul 06 11:32:56 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!uu!apark From: apark@uu.net (Amy Park) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul06.113256.7886@uu.net> Date: Wed, 06 Jul 1994 11:32:56 GMT References: <1994Jul03.205756.3365@pacbell.net> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: Netscape 1.1N Lines: 12 In article <1994Jul03.205756.3365@pacbell.net>, jnilsson@pacbell.net (Julien Nilsson) 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. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Amy Park Practical Peripherals 14.4 @ 9600 Telebit bps "Measuring a record you own is listening, not piracy." From tsantos@pipeline.com Thu Jul 07 09:14:56 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!tsantos From: tsantos@pipeline.com (Tyler Santos) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul07.091456.6483@pipeline.com> Date: Thu, 07 Jul 1994 09:14:56 GMT References: <1994Jul03.205756.3365@pacbell.net> <1994Jul05.011056.2293@mit.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1994Jul05.011056.2293@mit.edu>, jpetrov@mit.edu (Jens Petrov) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Tyler Santos "Row 14. No joke." PC-9821Ap2 (NEC) / SunOS 4.1.4