[comp.sys.amiga] 620x400 interlace vs

STU00@vx.acss.umn.edu (Stuart Stanley) (05/02/89)

Heres a question to the net that I think might clear things up some:

I was fiddling around opening screens and stuff the other day, and decided
to try changing the definition of the screen size to *MUCH* bigger than
the physical screen. I found that I could then draw shapes that would go
off the screen in that direction. (And not whomp on some poor unsuspectiong
memory list ;) It was even drawing points on the physical screen PAST
the normal 620.

So heres the question.  Suppose you had a RGB monitor that actaully was,
say 1048*400.  Could you open a screen 1048*400 and NOT be in interlace
mode?  If you could, I think this would lead to the following change
in 1.4:


	A change to prefenreces that defines the physical size of your 
		screen for non-interlace and interlace mode

	An easy way (defaults in OpenScreen?) to get to these values when
		you open a screen.


Then again, I could be totaly dead in the water!  Could someone fill me
in on this stuff.
					
					Thanks,.
					Stuart STanley
					STU00@UMNACVX

thomas@cbmvax.UUCP (Dave Thomas QA) (05/02/89)

In article <14423@louie.udel.EDU> STU00@vx.acss.umn.edu (Stuart Stanley) writes:
> 
> 
> Heres a question to the net that I think might clear things up some:
> 
    [background text deleted]
> 
> So heres the question.  Suppose you had a RGB monitor that actaully was,
> say 1048*400.  Could you open a screen 1048*400 and NOT be in interlace
> mode?  

This won't work.  Just because the monitor is capable of displaying an image
that's 1048x400 doesn't mean that the Amiga can generate one.  The limitation
on horizontal resolution is the speed at which pixels are displayed.  The
Amiga displays 70ns pixels in hires and 140ns pixels in lores.  This is
what determines the resolution of the displayed image and won't change unless
hardware in the Amiga changes (e.g. ECS).

           Dave
-- 
Dave Thomas, Commodore Amiga Test Engineering
UUCP  ...{allegra,rutgers}!cbmvax!thomas