From ksantos@berkeley.edu Wed Dec 06 07:03:27 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!berkeley!ksantos From: ksantos@berkeley.edu (Kirsty Santos) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec06.070327.2276@berkeley.edu> Date: Wed, 06 Dec 1995 07:03:27 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop. 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? -- Kirsty Santos *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From kperez@panix.com Wed Dec 06 11:12:27 1995 Path: ashpoly!cascade!brgate!saturno!panix!kperez From: kperez@panix.com (Kirsty Pérez) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec06.111227.8689@panix.com> Date: Wed, 06 Dec 1995 11:12:27 GMT References: <1995Dec06.070327.2276@berkeley.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Dec06.070327.2276@berkeley.edu>, ksantos@berkeley.edu (Kirsty Santos) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Kirsty Pérez Zyxel U-1496E @ 9600 Telebit bps "Tape doesn't lie at 02:14. Ears do." From glopez@mit.edu Wed Dec 06 22:49:27 1995 Path: ashpoly!cascade!transat!ukc!fennimore!mit!glopez From: glopez@mit.edu (Göran López) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec06.224927.7027@mit.edu> Date: Wed, 06 Dec 1995 22:49:27 GMT References: <1995Dec06.070327.2276@berkeley.edu> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Dec06.070327.2276@berkeley.edu>, ksantos@berkeley.edu (Kirsty Santos) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Göran López *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From rpopov@cam.ac.uk Thu Dec 07 18:15:27 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cam!rpopov From: rpopov@cam.ac.uk (Rodrigo Popov) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec07.181527.7390@cam.ac.uk> Date: Thu, 07 Dec 1995 18:15:27 GMT References: <1995Dec06.070327.2276@berkeley.edu> <1995Dec06.224927.7027@mit.edu> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Dec06.224927.7027@mit.edu>, glopez@mit.edu (Göran López) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Rodrigo Popov Opinions expressed are solely my own and not those of University of Cambridge Computer Laboratory. ------------------------------------------------------------ From dlindqvist@uu.net Fri Dec 08 09:15:27 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!uu!dlindqvist From: dlindqvist@uu.net (Dmitri Lindqvist) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec08.091527.4875@uu.net> Date: Fri, 08 Dec 1995 09:15:27 GMT References: <1995Dec06.070327.2276@berkeley.edu> <1995Dec06.111227.8689@panix.com> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Dec06.111227.8689@panix.com>, kperez@panix.com (Kirsty Pérez) 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. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Dmitri Lindqvist -- UUNET Technologies, Falls Church VA "Row 14. No joke."