On Mon, 8 May 2000, David Pinson wrote:
> Good news,
> This is to announce an implementation of Mode 12h support
> for dosemu under X11 using instruction emulation.
> The hack was done by David Hindman, who adapted the methods
> of bochs for use in dosemu.
>
> At this stage it would be good if people interested in
> mode 12h X11 support downloaded the files and tested it
> with thier configurations.
>
> http://www.io.com/~dhindman/VGAMode12h/index.html
Good news indeed! It should not be too difficult to adapt this to support
other planar modes 0Dh to 11h as well.
A few things I wondered about:
1. the README says:
Borland's BGI requires the old IBM 8x8 ASCII font table to be present
at memory address F000:FA6E. This hack loads a 8x8 font table at the
expected addresses when VGA mode 12h is entered. (I sure hope nothing
important lives there.) The font I used is ugly but free.
I wonder whether this is necessary (it is not for me). It used to be in
0.98.*, but was fixed somewhere in the 0.99 series, and now copies this
font from the real BIOS. Or are there some BIOSes which don't include this
font any more?
2. Isn't there some double work going on here w.r.t. the cpuemu code,
which is present in 0.99.x but not in 1.0.0?
> Depending on the type of application, performance is
> not too bad. (I have been using protel easytrax with
> a 466MHz celeron quite acceptably - Yes I know that
> the original application ran fast on a 386....)
It could well be possible to speed-optimize the emulation by throwing in
some assembly language.
Bart
