From gschneider@pacbell.net Tue Jul 19 16:09:10 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!pacbell!gschneider From: gschneider@pacbell.net (Graham Schneider) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul19.160910.3303@pacbell.net> Date: Tue, 19 Jul 1994 16:09:10 GMT Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 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. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Graham Schneider *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0 From yokonkwo@ox.ac.uk Thu Jul 21 17:29:10 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!ox!yokonkwo From: yokonkwo@ox.ac.uk (Yuki Okonkwo) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul21.172910.2645@ox.ac.uk> Date: Thu, 21 Jul 1994 17:29:10 GMT References: <1994Jul19.160910.3303@pacbell.net> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Jul19.160910.3303@pacbell.net>, gschneider@pacbell.net (Graham Schneider) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Yuki Okonkwo Practical Peripherals 14.4 @ 9600 Telebit bps "The carrier frequency does not drift by accident." From astewart@demon.co.uk Fri Jul 22 15:28:10 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!demon!astewart From: astewart@demon.co.uk (Anton Stewart) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul22.152810.4780@demon.co.uk> Date: Fri, 22 Jul 1994 15:28:10 GMT References: <1994Jul19.160910.3303@pacbell.net> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: Netscape 1.1N Lines: 12 In article <1994Jul19.160910.3303@pacbell.net>, gschneider@pacbell.net (Graham Schneider) 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. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Anton Stewart Zyxel U-1496E @ 14,400 bps "5 sigma is a discovery. 7 is a question." From nstewart@ox.ac.uk Sun Jul 24 03:19:10 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!ox!nstewart From: nstewart@ox.ac.uk (Natalia Stewart) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul24.031910.6553@ox.ac.uk> Date: Sun, 24 Jul 1994 03:19:10 GMT References: <1994Jul19.160910.3303@pacbell.net> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1994Jul19.160910.3303@pacbell.net>, gschneider@pacbell.net (Graham Schneider) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Natalia Stewart Tape trading list upon request. SASE required for international mail.