Re: speed up the apple

[dempson@actrix.gen.nz (David Empson)]

Guillaume Tello <houten.van@wanadoo.fr> wrote:

> "David Empson" <dempson@actrix.gen.nz> a �crit dans le message de news:
> 1huhxaf.utwqqj15iozj3N%dempson@actrix.gen.nz...
> > Guillaume Tello <houten.van@wanadoo.fr> wrote:
> >
> >> just a thought, I have a graphic card in my IIe, so I don't use the
> >> standard
> >> video output of the console.
> >
> > Further details, please? What is this card?
> >
> > If your "graphic card" is just generating RGB output then it is
> > accessing exactly the same memory areas in the Apple II as the built-in
> > video generator does to get the video data to be displayed.
> 
>     The graphic card is "Le chat mauve" with SCART output.

My six months learning French (before I started using an Apple II) is a
bit limited. Does that translate as "The purple cat?" Not one I've heard
of.

My understanding is that SCART supports several video output methods
using the same connector: at least composite and some derivatives with
separate luminance and chrominance, possibly also RGB. That doesn't
narrow it down much.

If the card displays the standard Apple II video modes (text, lo-res
graphics, hi-res graphics) and works with all software without requiring
special drivers, then it is using the standard Apple II video display
buffers and just mirroring the built-in video generator. It might even
be hooked into the output side of the built-in video to get some signals
and avoid having to duplicate some parts.

An example of a video card that doesn't use the built-in display
hardware is an old Apple II 80-column card. These have their own
character generator and require the use of character I/O through the
slot to write data to the screen, with embedded control characters. They
can be compatible with a wide range of programs that use the standard
output calls, but not with any which write directly to the screen memory
or use the low level monitor calls to manipulate the display.

-- 
David Empson
dempson@actrix.gen.nz