From fsanchez@netcom.com Tue Jul 04 10:09:32 1995 Path: ashpoly!cascade!mxgate!coyoacan!netcom!fsanchez From: fsanchez@netcom.com (Freya Sánchez) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul04.100932.7906@netcom.com> Date: Tue, 04 Jul 1995 10:09:32 GMT Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Freya Sánchez *PLONK* filter active for trolls. Atari TT030 - NetBSD 1.0 From tkarlsson@cmu.edu Wed Jul 05 11:39:32 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!cmu!tkarlsson From: tkarlsson@cmu.edu (Tyler Karlsson) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul05.113932.3743@cmu.edu> Date: Wed, 05 Jul 1995 11:39:32 GMT References: <1995Jul04.100932.7906@netcom.com> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Jul04.100932.7906@netcom.com>, fsanchez@netcom.com (Freya Sánchez) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? PGP Public key available via finger or upon request. -- Tyler Karlsson Tape trading list upon request. SASE required for international mail. From ncampbell@stanford.edu Fri Jul 07 02:57:32 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!stanford!ncampbell From: ncampbell@stanford.edu (Natalia Campbell) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul07.025732.4163@stanford.edu> Date: Fri, 07 Jul 1995 02:57:32 GMT References: <1995Jul04.100932.7906@netcom.com> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1995Jul04.100932.7906@netcom.com>, fsanchez@netcom.com (Freya Sánchez) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. If you are posting from AOL, please read RFC 1036 before posting again. -- Natalia Campbell Zyxel U-1496E @ 14,400 bps "In theory there is no difference between theory and practice."