From slee@kiae.su Thu Jun 09 00:25:07 1994 Path: ashpoly!cascade!transat!ukc!fennimore!kiae!slee From: slee@kiae.su (Sun-mi Lee) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jun09.002507.6021@kiae.su> Date: Thu, 09 Jun 1994 00:25:07 GMT Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su 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. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Sun-mi Lee Practical Peripherals 14.4 @ ISDN 64k bps "5 sigma is a discovery. 7 is a question." From vmartinez@stanford.edu Fri Jun 10 17:25:07 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!stanford!vmartinez From: vmartinez@stanford.edu (Valeria Martínez) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jun10.172507.1955@stanford.edu> Date: Fri, 10 Jun 1994 17:25:07 GMT References: <1994Jun09.002507.6021@kiae.su> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jun09.002507.6021@kiae.su>, slee@kiae.su (Sun-mi Lee) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Valeria Martínez "The hatch is open. Is anyone listening?" Pentium 90 (OS/2 Warp) / TOS 4.04 From csmirnov@clari.net Sat Jun 11 11:15:07 1994 Path: ashpoly!cascade!mxgate!coyoacan!clari!csmirnov From: csmirnov@clari.net (Camila Smirnov) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jun11.111507.2292@clari.net> Date: Sat, 11 Jun 1994 11:15:07 GMT References: <1994Jun09.002507.6021@kiae.su> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1994Jun09.002507.6021@kiae.su>, slee@kiae.su (Sun-mi Lee) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! 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. -- Camila Smirnov Tape trading list upon request. SASE required for international mail.