From bnilsson@stanford.edu Sun Apr 07 03:19:14 1996 Path: ashpoly!cascade!mxgate!coyoacan!stanford!bnilsson From: bnilsson@stanford.edu (Bruno Nilsson) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Apr07.031914.6203@stanford.edu> Date: Sun, 07 Apr 1996 03:19:14 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: Netscape 1.1N Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. 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? -- === Bruno Nilsson === Dept of Electrical Engineering, Stanford University Computer Systems Lab "The carrier frequency does not drift by accident." From mrodriguez@kth.se Sun Apr 07 11:07:14 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!kth!mrodriguez From: mrodriguez@kth.se (Mei Rodríguez) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Apr07.110714.4887@kth.se> Date: Sun, 07 Apr 1996 11:07:14 GMT References: <1996Apr07.031914.6203@stanford.edu> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Apr07.031914.6203@stanford.edu>, bnilsson@stanford.edu (Bruno Nilsson) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Mei Rodríguez *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0 From kkarlsson@unam.mx Mon Apr 08 04:38:14 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!unam!kkarlsson From: kkarlsson@unam.mx (Karen Karlsson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Apr08.043814.2899@unam.mx> Date: Mon, 08 Apr 1996 04:38:14 GMT References: <1996Apr07.031914.6203@stanford.edu> <1996Apr07.110714.4887@kth.se> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Apr07.110714.4887@kth.se>, mrodriguez@kth.se (Mei Rodríguez) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- === Karen Karlsson === Dept of Electrical Engineering, Universidad Nacional Autónoma de México (DGSCA) "5 sigma is a discovery. 7 is a question."