From oweber@pacbell.net Fri Nov 03 06:47:41 1995 Path: ashpoly!cascade!bigsur!pacbell!oweber From: oweber@pacbell.net (Olga Weber) Newsgroups: comp.sys.m68k Subject: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov03.064741.4851@pacbell.net> Date: Fri, 03 Nov 1995 06:47:41 GMT Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: NewsWatcher 2.0b24 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. -- Olga Weber | oweber@pacbell.net PGP Key fingerprint: 2730 66EA FE52 B683 "Keep the channels open." From ksouza@cam.ac.uk Fri Nov 03 15:31:41 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!cam!ksouza From: ksouza@cam.ac.uk (Kenji Souza) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov03.153141.1274@cam.ac.uk> Date: Fri, 03 Nov 1995 15:31:41 GMT References: <1995Nov03.064741.4851@pacbell.net> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Nov03.064741.4851@pacbell.net>, oweber@pacbell.net (Olga Weber) 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. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Kenji Souza "We don't sign stars. We build them." NeXTstation Turbo Color / AmigaOS 3.1 From creyes@utexas.edu Sat Nov 04 08:34:41 1995 Path: ashpoly!cascade!mxgate!coyoacan!utexas!creyes From: creyes@utexas.edu (Camila Reyes) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov04.083441.1651@utexas.edu> Date: Sat, 04 Nov 1995 08:34:41 GMT References: <1995Nov03.064741.4851@pacbell.net> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Nov03.064741.4851@pacbell.net>, oweber@pacbell.net (Olga Weber) 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. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Camila Reyes *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From glopez@tum.de Sat Nov 04 19:45:41 1995 Path: ashpoly!cascade!bigsur!tum!glopez From: glopez@tum.de (Graham López) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov04.194541.2145@tum.de> Date: Sat, 04 Nov 1995 19:45:41 GMT References: <1995Nov03.064741.4851@pacbell.net> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Nov03.064741.4851@pacbell.net>, oweber@pacbell.net (Olga Weber) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Graham López Hayes Optima 288 @ 19,200 bps "Measuring a record you own is listening, not piracy."