Christopher Kovacs writes:
>
> On Tue, Sep 28, 1999 at 10:22:00AM +0100, Alistair Riddoch wrote:
> > Thomas Stewart writes:
> > > Or is there a better way to use the two cards together? DOS does not do this
> > > very well (appart from a few utills that switch the screen, and a few apps
> > > that support it (tcc).)
> >
> > There is no current support for this in the ELKS code, but it does appeal
> > to me. Any idea how it can be done at a low level anyone? If there is
> > source code available for the DOS software, then it could be ported.
>
> There is no need for any trick - as far as I can recall, the only thing
> one has to is to address the vga's buffer at 0xb8000 and the herc's at
> 0xb0000. It can be done from any program.
>
> mov ax, 0b000h
> push ax
> pop es
> mov es:[0], 030h
> mov ax, 0b800h
> push ax
> pop es
> mov es:[0], 031h
> ret
>
> writes a '0' to the herc and a '1' to the vga.
>
> Sorry if this was obivious to everyone.
Is it as simple as having a VGA card and a herc, and just writing to them
both separatly? I would have thought there would be problems with
initialising the hardware, and detecting which was present.
If it is this simple, then adding dual monitor as an option to the dircon.c
driver should be quite easy. The only sticking point is that I don't have a
herc card, or a mono monitor.
Al
