[GEM Development] Reconstructed GEM/4.0 driver source

[John Elliott]

A couple of days ago, I wrote:
>   The machine-specific bits of a GEM/4.0 driver appear to be pretty much
> identical to the corresponding files in GEM/3.1, so it should be possible to
> backport the Genoa 800x600 driver (if anyone's got a Genoa SVGA card) or
> forward-port earlier drivers like CGA.

  I have now done so. The FreeGEM driver page
<http://www.seasip.info/Gem/drivers.html> now includes a separate pack of
GEM/4 (ie, Artline II) drivers with FreeGEM enhancements - codepage
support and high-resolution timer support.

  The pack contains FreeGEM updates of the original seven drivers (VGA,
MCGA, EGA, Hercules, AT&T 6300, Genius, Genoa SVGA) plus forward ports of
the two 800x600x16 drivers (VESA and non-VESA).

  I've also included a port of the 1024x768x256-colour driver for fun, but
Artline doesn't really work with it. The colour gradient support doesn't
work properly on a display with more than four planes, and it has the usual
distressing tendency to run out of memory.

  I don't currently plan to forward-port any of the other FreeGEM drivers to
GEM 4.0, unless someone asks me to. About the only other ones which might be
useful would be EGA mono and the two ViewMAX multiple-resolution drivers.
Likewise, unless I ever come across a Genoa SVGA card, I don't plan to 
backport its driver to FreeGEM.

-- 
John Elliott