Article View: comp.sys.amiga.tech
Article #4672a little programming help please
From: Jesse S. Lackey
Date: Fri, 03 Aug 1990 01:39
Date: Fri, 03 Aug 1990 01:39
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1414 bytes
hi. I'm just getting started w/amiga programming, and I want to make a dirt cheap digitizer as a simple digital 'scope. On page 331 in the Amiga Hardware Reference Manual there is a sample program which shuts off all interrupts, then blinks the LED at 3ms intervals using one of the 8520 timers. I wrote a (hopefully) equivalent program in C (lattice 5.0) but it doesn't do anything at all. If I use another timer (timer A on CIAB) and don't shut off interrupts, it will work - but is very erratic due to the task switching going on. questions: 1. Does the c.o lattice C startup file require interrupts to operate? I looked at the code out of LC and it seemed to be straightforward. 2. When interrupts are shut off by move.w #$7fff,dmacon(a3) with a3= addr of custom chips, does any task switching occur? Any and all help is appreciated. jslackey@grissom.jpl.nasa.gov
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!mailrus!wuarchive!zaphod.mps.ohio-state.edu!sdd.hp.com!decwrl!elroy.jpl.nasa.gov!jpl-devvax!jslackey From: jslackey@kilroy.Jpl.Nasa.Gov (Jesse S. Lackey) Newsgroups: comp.sys.amiga.tech Subject: a little programming help please Summary: interrupts, timer Keywords: timer, interrupts Message-ID: <8983@jpl-devvax.JPL.NASA.GOV> Date: 3 Aug 90 01:39:11 GMT Sender: news@jpl-devvax.JPL.NASA.GOV Organization: Jet Propulsion Laboratory, Pasadena, CA Lines: 24