From jkowalski@kiae.su Sat May 25 18:29:23 1996 Path: ashpoly!cascade!brgate!saturno!kiae!jkowalski From: jkowalski@kiae.su (Joachim Kowalski) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May25.182923.9084@kiae.su> Date: Sat, 25 May 1996 18:29:23 GMT Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: WinVN 0.99.5 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. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Joachim Kowalski | jkowalski@kiae.su PGP Key fingerprint: B8E2 AC08 A090 356E "Keep the channels open." From fpark@cam.ac.uk Sun May 26 06:00:23 1996 Path: ashpoly!cascade!bigsur!cam!fpark From: fpark@cam.ac.uk (Fiona Park) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May26.060023.6753@cam.ac.uk> Date: Sun, 26 May 1996 06:00:23 GMT References: <1996May25.182923.9084@kiae.su> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1996May25.182923.9084@kiae.su>, jkowalski@kiae.su (Joachim Kowalski) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Fiona Park "The carrier frequency does not drift by accident." 486DX4/100 (FreeBSD 2.0.5) / SunOS 4.1.4 From mkarlsson@cam.ac.uk Mon May 27 02:05:23 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!mkarlsson From: mkarlsson@cam.ac.uk (Marta Karlsson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May27.020523.3417@cam.ac.uk> Date: Mon, 27 May 1996 02:05:23 GMT References: <1996May25.182923.9084@kiae.su> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996May25.182923.9084@kiae.su>, jkowalski@kiae.su (Joachim Kowalski) 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! -- Marta Karlsson Practical Peripherals 14.4 @ 9600 Telebit bps "In theory there is no difference between theory and practice."