From anovak@mindspring.com Tue Nov 01 01:48:06 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!mindspring!anovak From: anovak@mindspring.com (Andrei Novak) Newsgroups: comp.sys.m68k Subject: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Nov01.014806.9929@mindspring.com> Date: Tue, 01 Nov 1994 01:48:06 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: WinVN 0.99.5 Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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! Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Andrei Novak *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From fhughes@purdue.edu Tue Nov 01 21:55:06 1994 Path: ashpoly!cascade!brgate!saturno!purdue!fhughes From: fhughes@purdue.edu (Freya Hughes) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Nov01.215506.1652@purdue.edu> Date: Tue, 01 Nov 1994 21:55:06 GMT References: <1994Nov01.014806.9929@mindspring.com> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Nov01.014806.9929@mindspring.com>, anovak@mindspring.com (Andrei Novak) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Freya Hughes | fhughes@purdue.edu PGP Key fingerprint: 6A43 AD78 C3C4 391A "Keep the channels open." From mfournier@purdue.edu Wed Nov 02 23:33:06 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!purdue!mfournier From: mfournier@purdue.edu (Mike Fournier) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Nov02.233306.2859@purdue.edu> Date: Wed, 02 Nov 1994 23:33:06 GMT References: <1994Nov01.014806.9929@mindspring.com> <1994Nov01.215506.1652@purdue.edu> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Nov01.215506.1652@purdue.edu>, fhughes@purdue.edu (Freya Hughes) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Mike Fournier *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From jchoi@delphi.com Sat Nov 05 00:47:06 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!delphi!jchoi From: jchoi@delphi.com (Ji-woo Choi) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Nov05.004706.7405@delphi.com> Date: Sat, 05 Nov 1994 00:47:06 GMT References: <1994Nov01.014806.9929@mindspring.com> <1994Nov01.215506.1652@purdue.edu> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: Netscape 1.1N Lines: 11 In article <1994Nov01.215506.1652@purdue.edu>, fhughes@purdue.edu (Freya Hughes) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Top-posters will be placed in my ~/.killfile without notice. -- Ji-woo Choi | jchoi@delphi.com PGP Key fingerprint: 792F 34B2 7F78 13F6 "Keep the channels open."