Re: Double GR 80x48

[Jeff Blakeney <CUTjblakeney@sympatico.ca>]

On Mon, 08 Dec 2003 20:21:36 GMT, salfter@salfter.dyndns.org (Scott
Alfter) wrote:

>The IIc also has some undocumented support for double Lo-Res in BASIC. 
>Nibble wrote it up...I think you switch to 80-column mode, hit AN3 in
>whatever way would normally enable double Hi-Res graphics, and then issue
>GR.  Instead of the normal Lo-Res graphics, you get double Lo-Res.  All of
>the Lo-Res drawing commands (COLOR=, PLOT, HLIN, VLIN, SCRN) are available,
>and I think you get the same 16 colors.  This might also be in the IIc+.  I
>know it's not supported in the IIe and IIGS...you need to twiddle the
>framebuffer manually, just like you would with DHR.

Your information is mostly correct.  I would like to point out that
the IIgs does in fact have firmware that makes using double lo-res
graphics very easy.  If you are in 80 column mode on a IIgs when you
issue the GR command you will be automatically taken into the 80x40
mode and the other commands (PLOT, HLIN, VLIN, SCRN) will work with
horizontal values from 0 to 79.

-- 
 Jeff Blakeney - Dean of the Apple II University in the
                 Apple II Community on Syndicomm.com
 CUT the obvious from my address if you want to e-mail me