From sstewart@unam.mx Thu Dec 21 04:59:00 1995 Path: ashpoly!cascade!brgate!saturno!unam!sstewart From: sstewart@unam.mx (Steve Stewart) Newsgroups: comp.sys.m68k Subject: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec21.045900.6101@unam.mx> Date: Thu, 21 Dec 1995 04:59:00 GMT Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. 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. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Steve Stewart Hayes Optima 288 @ 14,400 bps "Row 14. No joke." From kschneider@kiae.su Fri Dec 22 03:01:00 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!kiae!kschneider From: kschneider@kiae.su (Kirsty Schneider) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec22.030100.5894@kiae.su> Date: Fri, 22 Dec 1995 03:01:00 GMT References: <1995Dec21.045900.6101@unam.mx> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Dec21.045900.6101@unam.mx>, sstewart@unam.mx (Steve Stewart) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > 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. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- === Kirsty Schneider === Dept of Electrical Engineering, Kurchatov Institute of Atomic Energy, Moscow "Hardware is temporary. The signal survives."