From bkang@inria.fr Sun Jul 23 16:41:20 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!inria!bkang From: bkang@inria.fr (Brian Kang) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul23.164120.1096@inria.fr> Date: Sun, 23 Jul 1995 16:41:20 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] 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. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Brian Kang *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From ahughes@mindspring.com Tue Jul 25 16:06:20 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!mindspring!ahughes From: ahughes@mindspring.com (Amy Hughes) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul25.160620.6995@mindspring.com> Date: Tue, 25 Jul 1995 16:06:20 GMT References: <1995Jul23.164120.1096@inria.fr> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Jul23.164120.1096@inria.fr>, bkang@inria.fr (Brian Kang) writes: > 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. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Amy Hughes Opinions expressed are solely my own and not those of MindSpring Enterprises. ------------------------------------------------------------ From mhughes@mindspring.com Thu Jul 27 04:07:20 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!mindspring!mhughes From: mhughes@mindspring.com (Min-jun Hughes) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul27.040720.4561@mindspring.com> Date: Thu, 27 Jul 1995 04:07:20 GMT References: <1995Jul23.164120.1096@inria.fr> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Jul23.164120.1096@inria.fr>, bkang@inria.fr (Brian Kang) writes: > 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. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. PGP Public key available via finger or upon request. -- Min-jun Hughes -- MindSpring Enterprises "Row 14. No joke." From mivanov@cam.ac.uk Fri Jul 28 01:12:20 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cam!mivanov From: mivanov@cam.ac.uk (Min-jun Ivanov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul28.011220.4923@cam.ac.uk> Date: Fri, 28 Jul 1995 01:12:20 GMT References: <1995Jul23.164120.1096@inria.fr> <1995Jul27.040720.4561@mindspring.com> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Jul27.040720.4561@mindspring.com>, mhughes@mindspring.com (Min-jun Hughes) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. > PGP Public key available via finger or upon request. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- === Min-jun Ivanov === Dept of Electrical Engineering, University of Cambridge Computer Laboratory "In theory there is no difference between theory and practice." From iramirez@pipeline.com Sun Jul 30 03:56:20 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!pipeline!iramirez From: iramirez@pipeline.com (Ines Ramírez) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul30.035620.3577@pipeline.com> Date: Sun, 30 Jul 1995 03:56:20 GMT References: <1995Jul23.164120.1096@inria.fr> <1995Jul27.040720.4561@mindspring.com> <1995Jul28.011220.4923@cam.ac.uk> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Jul28.011220.4923@cam.ac.uk>, mivanov@cam.ac.uk (Min-jun Ivanov) writes: > Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Ines Ramírez Tape trading list upon request. SASE required for international mail.