From dstewart@tum.de Fri May 26 17:43:45 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!tum!dstewart From: dstewart@tum.de (Dmitri Stewart) Newsgroups: comp.sys.m68k Subject: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May26.174345.6412@tum.de> Date: Fri, 26 May 1995 17:43:45 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de 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. 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. -- Dmitri Stewart | dstewart@tum.de PGP Key fingerprint: 4E7D 3490 2621 1005 "Keep the channels open." From nhughes@utexas.edu Sun May 28 13:41:45 1995 Path: ashpoly!cascade!transat!ukc!fennimore!utexas!nhughes From: nhughes@utexas.edu (Nadia Hughes) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May28.134145.4219@utexas.edu> Date: Sun, 28 May 1995 13:41:45 GMT References: <1995May26.174345.6412@tum.de> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995May26.174345.6412@tum.de>, dstewart@tum.de (Dmitri Stewart) 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. -- Nadia Hughes *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0