From achoi@netcom.com Wed Mar 27 03:11:05 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!netcom!achoi From: achoi@netcom.com (Astrid Choi) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Mar27.031105.1639@netcom.com> Date: Wed, 27 Mar 1996 03:11:05 GMT Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com 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. 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! -- Astrid Choi *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From fsato@panix.com Thu Mar 28 00:42:05 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!panix!fsato From: fsato@panix.com (Freya Sato) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Mar28.004205.2996@panix.com> Date: Thu, 28 Mar 1996 00:42:05 GMT References: <1996Mar27.031105.1639@netcom.com> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Mar27.031105.1639@netcom.com>, achoi@netcom.com (Astrid Choi) 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. -- === Freya Sato === Dept of Electrical Engineering, Public Access Unix of New York "They will send a copy in my place." From ktanaka@tum.de Thu Mar 28 16:24:05 1996 Path: ashpoly!cascade!transat!ukc!fennimore!tum!ktanaka From: ktanaka@tum.de (Kenji Tanaka) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Mar28.162405.4665@tum.de> Date: Thu, 28 Mar 1996 16:24:05 GMT References: <1996Mar27.031105.1639@netcom.com> <1996Mar28.004205.2996@panix.com> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1996Mar28.004205.2996@panix.com>, fsato@panix.com (Freya Sato) 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. -- Kenji Tanaka -- Technische Universität München "We don't sign stars. We build them." From jchoi@stanford.edu Fri Mar 29 07:26:05 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!stanford!jchoi From: jchoi@stanford.edu (Jens Choi) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Mar29.072605.5585@stanford.edu> Date: Fri, 29 Mar 1996 07:26:05 GMT References: <1996Mar27.031105.1639@netcom.com> <1996Mar28.004205.2996@panix.com> <1996Mar28.162405.4665@tum.de> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Mar28.162405.4665@tum.de>, ktanaka@tum.de (Kenji Tanaka) 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. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Jens Choi Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab. ------------------------------------------------------------