From cpetrov@utexas.edu Fri Aug 18 05:14:55 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!utexas!cpetrov From: cpetrov@utexas.edu (Callum Petrov) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug18.051455.3839@utexas.edu> Date: Fri, 18 Aug 1995 05:14:55 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 11 Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. 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. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Callum Petrov Zyxel U-1496E @ 9600 Telebit bps "Hold for relay." From alee@earthlink.net Fri Aug 18 19:56:55 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!earthlink!alee From: alee@earthlink.net (Aiko Lee) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug18.195655.3766@earthlink.net> Date: Fri, 18 Aug 1995 19:56:55 GMT References: <1995Aug18.051455.3839@utexas.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Aug18.051455.3839@utexas.edu>, cpetrov@utexas.edu (Callum Petrov) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. > 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. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Aiko Lee Tape trading list upon request. SASE required for international mail.