From lsuzuki@purdue.edu Thu Jan 26 11:53:51 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!lsuzuki From: lsuzuki@purdue.edu (Lisa Suzuki) Newsgroups: comp.sys.m68k Subject: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan26.115351.6478@purdue.edu> Date: Thu, 26 Jan 1995 11:53:51 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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? -- Lisa Suzuki -- Purdue University Engineering Computer Network "5 sigma is a discovery. 7 is a question." From tsanchez@cmu.edu Sat Jan 28 12:41:51 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cmu!tsanchez From: tsanchez@cmu.edu (Tyler Sánchez) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan28.124151.5148@cmu.edu> Date: Sat, 28 Jan 1995 12:41:51 GMT References: <1995Jan26.115351.6478@purdue.edu> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Jan26.115351.6478@purdue.edu>, lsuzuki@purdue.edu (Lisa Suzuki) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Tyler Sánchez Zyxel U-1496E @ 9600 Telebit bps "A soul is not exclusive to biology." From snakamura@tum.de Mon Jan 30 01:27:51 1995 Path: ashpoly!cascade!brgate!saturno!tum!snakamura From: snakamura@tum.de (Steve Nakamura) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan30.012751.6706@tum.de> Date: Mon, 30 Jan 1995 01:27:51 GMT References: <1995Jan26.115351.6478@purdue.edu> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Jan26.115351.6478@purdue.edu>, lsuzuki@purdue.edu (Lisa Suzuki) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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. -- Steve Nakamura Tape trading list upon request. SASE required for international mail. From ksokolov@utexas.edu Mon Jan 30 21:31:51 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!utexas!ksokolov From: ksokolov@utexas.edu (Karen Sokolov) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan30.213151.6342@utexas.edu> Date: Mon, 30 Jan 1995 21:31:51 GMT References: <1995Jan26.115351.6478@purdue.edu> <1995Jan28.124151.5148@cmu.edu> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Jan28.124151.5148@cmu.edu>, tsanchez@cmu.edu (Tyler Sánchez) 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. > Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Karen Sokolov SupraFAXModem 28.8 @ ISDN 64k bps "We don't sign stars. We build them."