From mstewart@mit.edu Sat May 20 18:35:05 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!mit!mstewart From: mstewart@mit.edu (Min-jun Stewart) Newsgroups: comp.sys.m68k Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May20.183505.7828@mit.edu> Date: Sat, 20 May 1995 18:35:05 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 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. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Min-jun Stewart | mstewart@mit.edu PGP Key fingerprint: BC96 A2D5 70C4 141A "Keep the channels open." From rnakamura@cmu.edu Sun May 21 17:35:05 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cmu!rnakamura From: rnakamura@cmu.edu (Renata Nakamura) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May21.173505.9010@cmu.edu> Date: Sun, 21 May 1995 17:35:05 GMT References: <1995May20.183505.7828@mit.edu> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995May20.183505.7828@mit.edu>, mstewart@mit.edu (Min-jun Stewart) 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. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Renata Nakamura "In theory there is no difference between theory and practice." Sun SparcStation 20 / FreeBSD 2.1 From kgirard@tum.de Mon May 22 10:07:05 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!tum!kgirard From: kgirard@tum.de (Kenji Girard) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May22.100705.9284@tum.de> Date: Mon, 22 May 1995 10:07:05 GMT References: <1995May20.183505.7828@mit.edu> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1995May20.183505.7828@mit.edu>, mstewart@mit.edu (Min-jun Stewart) 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Kenji Girard Zyxel U-1496E @ 28,800 bps "Marcus is not one man." From odubois@purdue.edu Wed May 24 05:13:05 1995 Path: ashpoly!cascade!mxgate!coyoacan!purdue!odubois From: odubois@purdue.edu (Olga Dubois) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May24.051305.7645@purdue.edu> Date: Wed, 24 May 1995 05:13:05 GMT References: <1995May20.183505.7828@mit.edu> <1995May22.100705.9284@tum.de> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995May22.100705.9284@tum.de>, kgirard@tum.de (Kenji Girard) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Olga Dubois US Robotics Courier V.34 @ 28,800 bps "Measuring a record you own is listening, not piracy." From jsokolov@inria.fr Fri May 26 02:37:05 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!inria!jsokolov From: jsokolov@inria.fr (Julien Sokolov) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May26.023705.1601@inria.fr> Date: Fri, 26 May 1995 02:37:05 GMT References: <1995May20.183505.7828@mit.edu> <1995May22.100705.9284@tum.de> <1995May24.051305.7645@purdue.edu> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995May24.051305.7645@purdue.edu>, odubois@purdue.edu (Olga Dubois) writes: > PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- === Julien Sokolov === Dept of Electrical Engineering, INRIA Rocquencourt "Extraordinary claims require extraordinary spectra."