From rperez@hanse.de Sun May 01 06:35:09 1994 Path: ashpoly!cascade!transat!ukc!fennimore!hanse!rperez From: rperez@hanse.de (Rodrigo Pérez) Newsgroups: comp.sys.m68k Subject: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994May01.063509.4201@hanse.de> Date: Sun, 01 May 1994 06:35:09 GMT Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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? -- Rodrigo Pérez Tape trading list upon request. SASE required for international mail. From schoi@rwth-aachen.de Tue May 03 05:33:09 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!rwth-aachen!schoi From: schoi@rwth-aachen.de (Seo-yeon Choi) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994May03.053309.4157@rwth-aachen.de> Date: Tue, 03 May 1994 05:33:09 GMT References: <1994May01.063509.4201@hanse.de> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994May01.063509.4201@hanse.de>, rperez@hanse.de (Rodrigo Pérez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Seo-yeon Choi *PLONK* filter active for trolls. Atari Falcon 030 - NetBSD 1.0 From jmoreno@ox.ac.uk Tue May 03 14:42:09 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!ox!jmoreno From: jmoreno@ox.ac.uk (Ji-woo Moreno) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994May03.144209.5009@ox.ac.uk> Date: Tue, 03 May 1994 14:42:09 GMT References: <1994May01.063509.4201@hanse.de> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994May01.063509.4201@hanse.de>, rperez@hanse.de (Rodrigo Pérez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Ji-woo Moreno Zyxel U-1496E @ 33,600 bps "In theory there is no difference between theory and practice." From greyes@cmu.edu Thu May 05 09:04:09 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cmu!greyes From: greyes@cmu.edu (Graham Reyes) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994May05.090409.9731@cmu.edu> Date: Thu, 05 May 1994 09:04:09 GMT References: <1994May01.063509.4201@hanse.de> <1994May03.144209.5009@ox.ac.uk> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1994May03.144209.5009@ox.ac.uk>, jmoreno@ox.ac.uk (Ji-woo Moreno) writes: > PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Graham Reyes Tape trading list upon request. SASE required for international mail.