From cdubois@kth.se Thu May 23 16:27:19 1996 Path: ashpoly!cascade!brgate!saturno!kth!cdubois From: cdubois@kth.se (Camila Dubois) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May23.162719.4250@kth.se> Date: Thu, 23 May 1996 16:27:19 GMT Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. 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? -- Camila Dubois *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From mmacdonald@kiae.su Thu May 23 23:38:19 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!kiae!mmacdonald From: mmacdonald@kiae.su (Mikhail MacDonald) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May23.233819.8965@kiae.su> Date: Thu, 23 May 1996 23:38:19 GMT References: <1996May23.162719.4250@kth.se> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996May23.162719.4250@kth.se>, cdubois@kth.se (Camila Dubois) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > 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! -- Mikhail MacDonald -- Kurchatov Institute of Atomic Energy, Moscow "Marcus is not one man." From ilindqvist@hanse.de Sat May 25 05:09:19 1996 Path: ashpoly!cascade!transat!ukc!fennimore!hanse!ilindqvist From: ilindqvist@hanse.de (Ines Lindqvist) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May25.050919.2659@hanse.de> Date: Sat, 25 May 1996 05:09:19 GMT References: <1996May23.162719.4250@kth.se> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1996May23.162719.4250@kth.se>, cdubois@kth.se (Camila Dubois) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Ines Lindqvist Tape trading list upon request. SASE required for international mail. From ltakahashi@utexas.edu Mon May 27 05:02:19 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!utexas!ltakahashi From: ltakahashi@utexas.edu (Lisa Takahashi) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May27.050219.3850@utexas.edu> Date: Mon, 27 May 1996 05:02:19 GMT References: <1996May23.162719.4250@kth.se> <1996May25.050919.2659@hanse.de> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996May25.050919.2659@hanse.de>, ilindqvist@hanse.de (Ines Lindqvist) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. > Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Lisa Takahashi | ltakahashi@utexas.edu PGP Key fingerprint: 220C 8E93 4E6C B7F6 "Keep the channels open." From tsouza@cmu.edu Wed May 29 00:54:19 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cmu!tsouza From: tsouza@cmu.edu (Takeshi Souza) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996May29.005419.6938@cmu.edu> Date: Wed, 29 May 1996 00:54:19 GMT References: <1996May23.162719.4250@kth.se> <1996May23.233819.8965@kiae.su> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996May23.233819.8965@kiae.su>, mmacdonald@kiae.su (Mikhail MacDonald) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- === Takeshi Souza === Dept of Electrical Engineering, Carnegie Mellon University School of CS "In theory there is no difference between theory and practice."