From rweber@mindspring.com Tue Feb 13 09:49:16 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!mindspring!rweber From: rweber@mindspring.com (Renata Weber) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Feb13.094916.6840@mindspring.com> Date: Tue, 13 Feb 1996 09:49:16 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.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. 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? -- Renata Weber "A soul is not exclusive to biology." Acorn RiscPC 600 / TOS 4.04 From lito@pacbell.net Wed Feb 14 14:20:16 1996 Path: ashpoly!cascade!transat!ukc!fennimore!pacbell!lito From: lito@pacbell.net (Lars Ito) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Feb14.142016.5174@pacbell.net> Date: Wed, 14 Feb 1996 14:20:16 GMT References: <1996Feb13.094916.6840@mindspring.com> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Feb13.094916.6840@mindspring.com>, rweber@mindspring.com (Renata Weber) 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. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- Lars Ito Tape trading list upon request. SASE required for international mail.