From bfischer@inria.fr Sun Nov 26 21:57:37 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!inria!bfischer From: bfischer@inria.fr (Bill Fischer) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov26.215737.4693@inria.fr> Date: Sun, 26 Nov 1995 21:57:37 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr 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. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Bill Fischer "When every node is whole, the channel opens." Macintosh IIfx / NEXTSTEP 3.3 From mmartinez@rwth-aachen.de Tue Nov 28 13:52:37 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!rwth-aachen!mmartinez From: mmartinez@rwth-aachen.de (Mei Martínez) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov28.135237.4961@rwth-aachen.de> Date: Tue, 28 Nov 1995 13:52:37 GMT References: <1995Nov26.215737.4693@inria.fr> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Nov26.215737.4693@inria.fr>, bfischer@inria.fr (Bill Fischer) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- === Mei Martínez === Dept of Electrical Engineering, RWTH Aachen Informatik "The carrier frequency does not drift by accident." From emoreno@purdue.edu Thu Nov 30 00:49:37 1995 Path: ashpoly!cascade!bigsur!purdue!emoreno From: emoreno@purdue.edu (Elaine Moreno) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov30.004937.1672@purdue.edu> Date: Thu, 30 Nov 1995 00:49:37 GMT References: <1995Nov26.215737.4693@inria.fr> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Nov26.215737.4693@inria.fr>, bfischer@inria.fr (Bill Fischer) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- === Elaine Moreno === Dept of Electrical Engineering, Purdue University Engineering Computer Network "When every node is whole, the channel opens."