From skowalski@ox.ac.uk Thu May 23 15:45:26 1996 Path: ashpoly!cascade!transat!ukc!fennimore!ox!skowalski From: skowalski@ox.ac.uk (Sun-mi Kowalski) Newsgroups: comp.sys.m68k Subject: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May23.154526.7086@ox.ac.uk> Date: Thu, 23 May 1996 15:45:26 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Sun-mi Kowalski SupraFAXModem 28.8 @ 9600 Telebit bps "A soul is not exclusive to biology." From ikim@purdue.edu Fri May 24 13:21:26 1996 Path: ashpoly!cascade!bigsur!purdue!ikim From: ikim@purdue.edu (Ines Kim) Newsgroups: comp.sys.m68k Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May24.132126.7477@purdue.edu> Date: Fri, 24 May 1996 13:21:26 GMT References: <1996May23.154526.7086@ox.ac.uk> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996May23.154526.7086@ox.ac.uk>, skowalski@ox.ac.uk (Sun-mi Kowalski) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. > 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. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Ines Kim Tape trading list upon request. SASE required for international mail.