From iokonkwo@demon.co.uk Mon Dec 11 00:31:40 1995 Path: ashpoly!cascade!mxgate!coyoacan!demon!iokonkwo From: iokonkwo@demon.co.uk (Ines Okonkwo) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec11.003140.4220@demon.co.uk> Date: Mon, 11 Dec 1995 00:31:40 GMT Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk 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. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Ines Okonkwo Practical Peripherals 14.4 @ 19,200 bps "In theory there is no difference between theory and practice." From cpopov@pipeline.com Mon Dec 11 01:43:40 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!pipeline!cpopov From: cpopov@pipeline.com (Callum Popov) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec11.014340.2066@pipeline.com> Date: Mon, 11 Dec 1995 01:43:40 GMT References: <1995Dec11.003140.4220@demon.co.uk> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Dec11.003140.4220@demon.co.uk>, iokonkwo@demon.co.uk (Ines Okonkwo) 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Callum Popov "Do not worship the copy." Pentium 90 (OS/2 Warp) / AmigaOS 3.1 From moliveira@clari.net Tue Dec 12 01:05:40 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!clari!moliveira From: moliveira@clari.net (Matthias Oliveira) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec12.010540.4017@clari.net> Date: Tue, 12 Dec 1995 01:05:40 GMT References: <1995Dec11.003140.4220@demon.co.uk> <1995Dec11.014340.2066@pipeline.com> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Dec11.014340.2066@pipeline.com>, cpopov@pipeline.com (Callum Popov) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Matthias Oliveira Opinions expressed are solely my own and not those of ClariNet Communications Corp. ------------------------------------------------------------ From tsouza@unam.mx Tue Dec 12 21:12:40 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!unam!tsouza From: tsouza@unam.mx (Tomas Souza) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec12.211240.2998@unam.mx> Date: Tue, 12 Dec 1995 21:12:40 GMT References: <1995Dec11.003140.4220@demon.co.uk> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Dec11.003140.4220@demon.co.uk>, iokonkwo@demon.co.uk (Ines Okonkwo) 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. -- Tomas Souza | tsouza@unam.mx PGP Key fingerprint: F095 A6D1 9E57 9A3D "Keep the channels open."