From mlindqvist@cmu.edu Thu Feb 10 08:53:49 1994 Path: ashpoly!cascade!brgate!saturno!cmu!mlindqvist From: mlindqvist@cmu.edu (Marta Lindqvist) Newsgroups: comp.sys.m68k Subject: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb10.085349.2832@cmu.edu> Date: Thu, 10 Feb 1994 08:53:49 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: Netscape 1.1N Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Marta Lindqvist | mlindqvist@cmu.edu PGP Key fingerprint: 52F5 BEFF 53DE 0ECB "Keep the channels open." From ltakahashi@purdue.edu Sat Feb 12 11:42:49 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!ltakahashi From: ltakahashi@purdue.edu (Lisa Takahashi) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb12.114249.5675@purdue.edu> Date: Sat, 12 Feb 1994 11:42:49 GMT References: <1994Feb10.085349.2832@cmu.edu> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 11 In article <1994Feb10.085349.2832@cmu.edu>, mlindqvist@cmu.edu (Marta Lindqvist) 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. PGP Public key available via finger or upon request. -- Lisa Takahashi "Hardware is temporary. The signal survives." Atari TT030 / SunOS 4.1.4 From ljohansson@unam.mx Sun Feb 13 23:36:49 1994 Path: ashpoly!cascade!bigsur!unam!ljohansson From: ljohansson@unam.mx (Lars Johansson) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb13.233649.9707@unam.mx> Date: Sun, 13 Feb 1994 23:36:49 GMT References: <1994Feb10.085349.2832@cmu.edu> <1994Feb12.114249.5675@purdue.edu> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994Feb12.114249.5675@purdue.edu>, ltakahashi@purdue.edu (Lisa Takahashi) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. > PGP Public key available via finger or upon request. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- Lars Johansson "In theory there is no difference between theory and practice." PC-9821Ap2 (NEC) / System 7.5.1 From areyes@ox.ac.uk Tue Feb 15 06:45:49 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!ox!areyes From: areyes@ox.ac.uk (Aiko Reyes) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Feb15.064549.1212@ox.ac.uk> Date: Tue, 15 Feb 1994 06:45:49 GMT References: <1994Feb10.085349.2832@cmu.edu> <1994Feb12.114249.5675@purdue.edu> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Feb12.114249.5675@purdue.edu>, ltakahashi@purdue.edu (Lisa Takahashi) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. > PGP Public key available via finger or upon request. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Aiko Reyes | areyes@ox.ac.uk PGP Key fingerprint: C562 F2E4 DCC7 ABDF "Keep the channels open."