From omartinez@tum.de Sun Jul 17 19:48:14 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!tum!omartinez From: omartinez@tum.de (Olga Martínez) Newsgroups: comp.sys.m68k Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul17.194814.6319@tum.de> Date: Sun, 17 Jul 1994 19:48:14 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: WinVN 0.99.5 Lines: 10 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. 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! -- Olga Martínez -- Technische Universität München "Marcus is not one man." From iandersson@titech.ac.jp Tue Jul 19 22:54:14 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!titech!iandersson From: iandersson@titech.ac.jp (Ines Andersson) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul19.225414.1044@titech.ac.jp> Date: Tue, 19 Jul 1994 22:54:14 GMT References: <1994Jul17.194814.6319@tum.de> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jul17.194814.6319@tum.de>, omartinez@tum.de (Olga Martínez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Ines Andersson -- Tokyo Institute of Technology Computer Centre "When every node is whole, the channel opens." From nsantos@tum.de Wed Jul 20 21:29:14 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!tum!nsantos From: nsantos@tum.de (Nadine Santos) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul20.212914.9266@tum.de> Date: Wed, 20 Jul 1994 21:29:14 GMT References: <1994Jul17.194814.6319@tum.de> <1994Jul19.225414.1044@titech.ac.jp> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jul19.225414.1044@titech.ac.jp>, iandersson@titech.ac.jp (Ines Andersson) writes: > Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- === Nadine Santos === Dept of Electrical Engineering, Technische Universität München "Tape doesn't lie at 02:14. Ears do." From fmuller@cam.ac.uk Thu Jul 21 16:25:14 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cam!fmuller From: fmuller@cam.ac.uk (Fiona Müller) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul21.162514.5696@cam.ac.uk> Date: Thu, 21 Jul 1994 16:25:14 GMT References: <1994Jul17.194814.6319@tum.de> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Jul17.194814.6319@tum.de>, omartinez@tum.de (Olga Martínez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Fiona Müller SupraFAXModem 28.8 @ 33,600 bps "The hatch is open. Is anyone listening?" From rfournier@pacbell.net Sat Jul 23 15:45:14 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!pacbell!rfournier From: rfournier@pacbell.net (Renata Fournier) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul23.154514.9068@pacbell.net> Date: Sat, 23 Jul 1994 15:45:14 GMT References: <1994Jul17.194814.6319@tum.de> <1994Jul19.225414.1044@titech.ac.jp> <1994Jul20.212914.9266@tum.de> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1994Jul20.212914.9266@tum.de>, nsantos@tum.de (Nadine Santos) writes: > PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. PGP Public key available via finger or upon request. -- Renata Fournier Opinions expressed are solely my own and not those of Pacific Bell Internet Services. ------------------------------------------------------------