Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!uniwa!andreww
From: andreww@uniwa.uwa.oz (Andrew John Williams)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Using the copper
Message-ID: <1991Apr3.011632.21694@uniwa.uwa.oz>
Date: 3 Apr 91 01:16:32 GMT
References: <9104011518.35.1541@SAARAG>
Distribution: comp
Organization: University of Western Australia
Lines: 31

m_gietzen@saarag.zer.sub.org writes:


>  
>Once a guy asked about the reason of using the copper.

>I program games and know sth. about this wonderfull customchip.
>The simplest effect is the use of different palettes and different 
>screens in different resolutions.
>You can mirror pictures without any processingtime, stretch pictures,
                                                     ^^^^^^^^^^^^^^^^
I know someone who has achieved this on the C64. No I didn't believe it
either. He's got a full-screen picture (80*200, any pixel any colour)
and puts sinusoidal waves through it. With a scrolly message below. And
a very little red bar in the border to show how much CPU time is left.
This sometimes vanishes completely.

>rotate them and so on.
>Another great ability of the copper is that it is able to leave 
>interrupts. So you can exactly start a routine at the same 
>rasterpositon. (see rasterirqs on the C64...)

>Ciao,

John West (stealing Andrew's account)
I'd rather have a box of fish than a son like that


>		    Markus Gietzen

>PS: Sorry for my bad english!