From dsanchez@tum.de Fri Feb 25 05:17:12 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!tum!dsanchez From: dsanchez@tum.de (Diego Sánchez) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb25.051712.6336@tum.de> Date: Fri, 25 Feb 1994 05:17:12 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de 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. 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! -- Diego Sánchez *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0 From agirard@hanse.de Fri Feb 25 15:30:12 1994 Path: ashpoly!cascade!mxgate!coyoacan!hanse!agirard From: agirard@hanse.de (Amy Girard) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb25.153012.5820@hanse.de> Date: Fri, 25 Feb 1994 15:30:12 GMT References: <1994Feb25.051712.6336@tum.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Feb25.051712.6336@tum.de>, dsanchez@tum.de (Diego Sánchez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- Amy Girard Hayes Optima 288 @ 14,400 bps "In theory there is no difference between theory and practice." From ecampbell@mit.edu Fri Feb 25 21:19:12 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!mit!ecampbell From: ecampbell@mit.edu (Elaine Campbell) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb25.211912.9962@mit.edu> Date: Fri, 25 Feb 1994 21:19:12 GMT References: <1994Feb25.051712.6336@tum.de> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994Feb25.051712.6336@tum.de>, dsanchez@tum.de (Diego Sánchez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. If you are posting from AOL, please read RFC 1036 before posting again. -- Elaine Campbell Tape trading list upon request. SASE required for international mail. From asouza@stanford.edu Sat Feb 26 19:10:12 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!stanford!asouza From: asouza@stanford.edu (Amy Souza) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb26.191012.7850@stanford.edu> Date: Sat, 26 Feb 1994 19:10:12 GMT References: <1994Feb25.051712.6336@tum.de> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Feb25.051712.6336@tum.de>, dsanchez@tum.de (Diego Sánchez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > 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. -- Amy Souza *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0 From mdubois@u-tokyo.ac.jp Mon Feb 28 09:59:12 1994 Path: ashpoly!cascade!brgate!saturno!u-tokyo!mdubois From: mdubois@u-tokyo.ac.jp (Mateo Dubois) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb28.095912.5870@u-tokyo.ac.jp> Date: Mon, 28 Feb 1994 09:59:12 GMT References: <1994Feb25.051712.6336@tum.de> <1994Feb25.153012.5820@hanse.de> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1994Feb25.153012.5820@hanse.de>, agirard@hanse.de (Amy Girard) writes: > Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Mateo Dubois -- University of Tokyo Department of Information Science "We don't sign stars. We build them."