From hito@hanse.de Tue Mar 26 00:24:07 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!hito From: hito@hanse.de (Heather Ito) Newsgroups: comp.sys.m68k Subject: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Mar26.002407.4026@hanse.de> Date: Tue, 26 Mar 1996 00:24:07 GMT Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de 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? -- Heather Ito *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From kvasiliev@pacbell.net Tue Mar 26 15:19:07 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!pacbell!kvasiliev From: kvasiliev@pacbell.net (Karen Vasiliev) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Mar26.151907.1265@pacbell.net> Date: Tue, 26 Mar 1996 15:19:07 GMT References: <1996Mar26.002407.4026@hanse.de> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Mar26.002407.4026@hanse.de>, hito@hanse.de (Heather Ito) 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! -- Karen Vasiliev *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From lcampbell@purdue.edu Thu Mar 28 14:30:07 1996 Path: ashpoly!cascade!bigsur!purdue!lcampbell From: lcampbell@purdue.edu (Lucia Campbell) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Mar28.143007.7963@purdue.edu> Date: Thu, 28 Mar 1996 14:30:07 GMT References: <1996Mar26.002407.4026@hanse.de> <1996Mar26.151907.1265@pacbell.net> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Mar26.151907.1265@pacbell.net>, kvasiliev@pacbell.net (Karen Vasiliev) 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. -- Lucia Campbell "The carrier frequency does not drift by accident." Atari Falcon 030 / TOS 4.04