Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!munnari.oz.au!uniwa!peter From: peter@cutmcvax.cs.curtin.edu.au (Peter Wemm) Newsgroups: comp.sys.amiga.programmer Subject: Re: Copper SKIP does not skip WAIT!!!! Message-ID: Date: 4 Mar 91 09:13:26 GMT References: <1991Mar4.095014.7896@vax1.tcd.ie> Sender: usenet@uniwa.uwa.oz (USENET News System) Distribution: comp Organization: Curtin University of Technology, Computing Science Lines: 19 smcgerty@vax1.tcd.ie writes: [....] >Now that I think of it, I remember someone telling me that it was _quite_ >likely that the Copper _did_ read in the next instruction while waiting for a >raster position to arrive. This is so that a CWAIT&CMOVE combination will have >the CMOVE precalculated and 'ready to go' the _instant_ the CWAIT position >arrives. I am fairly sure you are right. I understand the next instruction is prefetched and decoded. When they say a cwait takes 6 clocks (or is that pixels??) I assume that includes getting the next unstruction ready. My guess is that a CWAIT 'breaks' the CSKIP instruction by accessing some of the components of the copper what are used during the wait. -- Peter Wemm ------------------------------------------------------------------------------ peter@cutmcvax.cs.curtin.edu.au (if fails, try peter@cutmcvax.oz.au)