Re: Double lowres graphics?

[Mike Pfaiffer <pfaiffer@mts.net>]

Dennis Jenkins wrote:
> 
> Is it possible to manipulate any Apple II system into generating double
> resolution low resolution graphics?  (ie, 80x40 or 80x48)?  I assume
> that I'd have to write my own code to plot the pixels instead of calling
> the routines built into Applesoft.
> 
> If it is possible, which models will it work on?  I'm primarily
> interested in getting this to work on a IIe, IIgs and the IIe card in my
> Mac LC-II.
> 
> If it is possible, then how would I access the AUX memory for
> read/writes to 0x400-0x7ff.  I seem to remember reading about how to do
> this from the book that came with the 80 column card.
> 
> If double low-res graphics are possible, I will write a library for the
> CC65 compiler to do the normal graphics primitives that one would expect
> (plot, peek (or SCRN() for the purists out there!), set color, cls, set
> mode, etc...)

	Oddly enough, for the machines you mentioned, double lores is
implemented in Applesoft. The only catch is you have to switch to the
mode to access it. I think there are only three settings which need to
be changed. This can be done through Applesoft as well. I think they are
the same settings needed for double hires except the lores setting is
selected instead of hires.

				Later
				Mike




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