From tcampbell@stanford.edu Sun Sep 25 02:22:10 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!stanford!tcampbell From: tcampbell@stanford.edu (Takeshi Campbell) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Sep25.022210.7146@stanford.edu> Date: Sun, 25 Sep 1994 02:22:10 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu 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. 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. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Takeshi Campbell *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From tlee@kth.se Mon Sep 26 22:03:10 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!kth!tlee From: tlee@kth.se (Takeshi Lee) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Sep26.220310.5161@kth.se> Date: Mon, 26 Sep 1994 22:03:10 GMT References: <1994Sep25.022210.7146@stanford.edu> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Sep25.022210.7146@stanford.edu>, tcampbell@stanford.edu (Takeshi Campbell) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Takeshi Lee -- Royal Institute of Technology, Stockholm "5 sigma is a discovery. 7 is a question."