From mtanaka@clari.net Sun Dec 04 16:38:14 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!clari!mtanaka From: mtanaka@clari.net (Mateo Tanaka) Newsgroups: comp.sys.m68k Subject: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec04.163814.7128@clari.net> Date: Sun, 04 Dec 1994 16:38:14 GMT Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 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. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Mateo Tanaka | mtanaka@clari.net PGP Key fingerprint: A7F6 2480 E867 51E5 "Keep the channels open." From hsokolov@kth.se Tue Dec 06 19:38:14 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!kth!hsokolov From: hsokolov@kth.se (Heather Sokolov) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec06.193814.1561@kth.se> Date: Tue, 06 Dec 1994 19:38:14 GMT References: <1994Dec04.163814.7128@clari.net> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Dec04.163814.7128@clari.net>, mtanaka@clari.net (Mateo Tanaka) 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. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- === Heather Sokolov === Dept of Electrical Engineering, Royal Institute of Technology, Stockholm "Row 14. No joke." From tandersson@tum.de Wed Dec 07 11:19:14 1994 Path: ashpoly!cascade!mxgate!coyoacan!tum!tandersson From: tandersson@tum.de (Thiago Andersson) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec07.111914.3623@tum.de> Date: Wed, 07 Dec 1994 11:19:14 GMT References: <1994Dec04.163814.7128@clari.net> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Dec04.163814.7128@clari.net>, mtanaka@clari.net (Mateo Tanaka) 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. -- === Thiago Andersson === Dept of Electrical Engineering, Technische Universität München "The carrier frequency does not drift by accident." From hgonzalez@purdue.edu Thu Dec 08 06:56:14 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!hgonzalez From: hgonzalez@purdue.edu (Heather González) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec08.065614.5935@purdue.edu> Date: Thu, 08 Dec 1994 06:56:14 GMT References: <1994Dec04.163814.7128@clari.net> <1994Dec06.193814.1561@kth.se> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Dec06.193814.1561@kth.se>, hsokolov@kth.se (Heather Sokolov) 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. -- Heather González SupraFAXModem 28.8 @ 33,600 bps "We don't sign stars. We build them."