From yfournier@utexas.edu Sat Feb 26 09:52:10 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!utexas!yfournier From: yfournier@utexas.edu (Yuki Fournier) Newsgroups: comp.sys.m68k Subject: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb26.095210.8975@utexas.edu> Date: Sat, 26 Feb 1994 09:52:10 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. 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. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Yuki Fournier Opinions expressed are solely my own and not those of University of Texas at Austin. ------------------------------------------------------------ From alindqvist@illinois.edu Sat Feb 26 19:27:10 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!illinois!alindqvist From: alindqvist@illinois.edu (Amy Lindqvist) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb26.192710.5544@illinois.edu> Date: Sat, 26 Feb 1994 19:27:10 GMT References: <1994Feb26.095210.8975@utexas.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 12 In article <1994Feb26.095210.8975@utexas.edu>, yfournier@utexas.edu (Yuki Fournier) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Amy Lindqvist | alindqvist@illinois.edu PGP Key fingerprint: E26E 3208 C9F9 899D "Keep the channels open." From lpark@demon.co.uk Sun Feb 27 16:53:10 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!demon!lpark From: lpark@demon.co.uk (Lisa Park) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb27.165310.5310@demon.co.uk> Date: Sun, 27 Feb 1994 16:53:10 GMT References: <1994Feb26.095210.8975@utexas.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1994Feb26.095210.8975@utexas.edu>, yfournier@utexas.edu (Yuki Fournier) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > 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. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Lisa Park Opinions expressed are solely my own and not those of Demon Internet Services UK. ------------------------------------------------------------ From tmoreau@kiae.su Mon Feb 28 09:19:10 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!kiae!tmoreau From: tmoreau@kiae.su (Tyler Moreau) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb28.091910.1726@kiae.su> Date: Mon, 28 Feb 1994 09:19:10 GMT References: <1994Feb26.095210.8975@utexas.edu> <1994Feb26.192710.5544@illinois.edu> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1994Feb26.192710.5544@illinois.edu>, alindqvist@illinois.edu (Amy Lindqvist) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Tyler Moreau SupraFAXModem 28.8 @ 9600 Telebit bps "Do not worship the copy."