From mito@earthlink.net Tue Mar 15 22:05:24 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!mito From: mito@earthlink.net (Mikhail Ito) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Mar15.220524.4665@earthlink.net> Date: Tue, 15 Mar 1994 22:05:24 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] 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. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Mikhail Ito *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From kwatanabe@purdue.edu Wed Mar 16 00:47:24 1994 Path: ashpoly!cascade!brgate!saturno!purdue!kwatanabe From: kwatanabe@purdue.edu (Kenji Watanabe) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Mar16.004724.8203@purdue.edu> Date: Wed, 16 Mar 1994 00:47:24 GMT References: <1994Mar15.220524.4665@earthlink.net> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Mar15.220524.4665@earthlink.net>, mito@earthlink.net (Mikhail Ito) 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Kenji Watanabe -- Purdue University Engineering Computer Network "The hatch is open. Is anyone listening?" From mcampbell@purdue.edu Wed Mar 16 06:56:24 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!purdue!mcampbell From: mcampbell@purdue.edu (Mathieu Campbell) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Mar16.065624.1069@purdue.edu> Date: Wed, 16 Mar 1994 06:56:24 GMT References: <1994Mar15.220524.4665@earthlink.net> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1994Mar15.220524.4665@earthlink.net>, mito@earthlink.net (Mikhail Ito) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. 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. -- Mathieu Campbell Opinions expressed are solely my own and not those of Purdue University Engineering Computer Network. ------------------------------------------------------------