From ymuller@illinois.edu Sun Jul 17 11:39:46 1994 Path: ashpoly!cascade!transat!ukc!fennimore!illinois!ymuller From: ymuller@illinois.edu (Yuki Müller) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul17.113946.6267@illinois.edu> Date: Sun, 17 Jul 1994 11:39:46 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. 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. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Yuki Müller Opinions expressed are solely my own and not those of University of Illinois Urbana-Champaign. ------------------------------------------------------------ From hlarsson@pacbell.net Sun Jul 17 22:27:46 1994 Path: ashpoly!cascade!bigsur!pacbell!hlarsson From: hlarsson@pacbell.net (Hana Larsson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul17.222746.9816@pacbell.net> Date: Sun, 17 Jul 1994 22:27:46 GMT References: <1994Jul17.113946.6267@illinois.edu> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jul17.113946.6267@illinois.edu>, ymuller@illinois.edu (Yuki Müller) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Hana Larsson "The carrier frequency does not drift by accident." Sun SparcStation 20 / NEXTSTEP 3.3 From mpopov@u-tokyo.ac.jp Tue Jul 19 06:02:46 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!u-tokyo!mpopov From: mpopov@u-tokyo.ac.jp (Mateo Popov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul19.060246.2541@u-tokyo.ac.jp> Date: Tue, 19 Jul 1994 06:02:46 GMT References: <1994Jul17.113946.6267@illinois.edu> <1994Jul17.222746.9816@pacbell.net> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Jul17.222746.9816@pacbell.net>, hlarsson@pacbell.net (Hana Larsson) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Mateo Popov US Robotics Courier V.34 @ 14,400 bps "Marcus is not one man."