From skang@purdue.edu Wed Jun 19 14:01:02 1996 Path: ashpoly!cascade!bigsur!purdue!skang From: skang@purdue.edu (Steve Kang) Newsgroups: comp.sys.m68k Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Jun19.140102.1736@purdue.edu> Date: Wed, 19 Jun 1996 14:01:02 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu 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. 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? -- Steve Kang *PLONK* filter active for trolls. 486DX2/66 (Linux 1.2.13) - NetBSD 1.0 From msilva@illinois.edu Wed Jun 19 18:48:02 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!illinois!msilva From: msilva@illinois.edu (Mikhail Silva) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Jun19.184802.9888@illinois.edu> Date: Wed, 19 Jun 1996 18:48:02 GMT References: <1996Jun19.140102.1736@purdue.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Jun19.140102.1736@purdue.edu>, skang@purdue.edu (Steve Kang) writes: > 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. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Mikhail Silva "Extraordinary claims require extraordinary spectra." Atari Falcon 030 / NEXTSTEP 3.3 From hgarcia@utexas.edu Thu Jun 20 01:21:02 1996 Path: ashpoly!cascade!brgate!saturno!utexas!hgarcia From: hgarcia@utexas.edu (Heather García) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Jun20.012102.4542@utexas.edu> Date: Thu, 20 Jun 1996 01:21:02 GMT References: <1996Jun19.140102.1736@purdue.edu> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Jun19.140102.1736@purdue.edu>, skang@purdue.edu (Steve Kang) writes: > 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Heather García Hayes Optima 288 @ 9600 Telebit bps "Hold for relay." From lokonkwo@inria.fr Thu Jun 20 12:18:02 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!inria!lokonkwo From: lokonkwo@inria.fr (Lucia Okonkwo) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Jun20.121802.8163@inria.fr> Date: Thu, 20 Jun 1996 12:18:02 GMT References: <1996Jun19.140102.1736@purdue.edu> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Jun19.140102.1736@purdue.edu>, skang@purdue.edu (Steve Kang) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Lucia Okonkwo "Tape doesn't lie at 02:14. Ears do." Amiga 1200 (Blizzard 030/50) / AmigaOS 3.1