[BRLTTY] BRLTTY under real Dos

[Samuel Thibault]

Nicolas Pitre, le Wed 03 May 2006 12:28:58 -0400, a écrit :
> On Wed, 3 May 2006, Samuel Thibault wrote:
> > Nicolas Pitre, le Wed 03 May 2006 12:08:01 -0400, a écrit :
> > > I hope no one sane is ever to consider trying to port BRLTTY to the x86 
> > > 16-bit real mode.
> > 
> > Why not? Brltty is just C code.
> 
> There are probably plenty of occurences all around where an int is 
> assumed to be 32 bits wide.

Ah, forgot that indeed...

> > A protected-mode TSR application is not particularly easy to write...
> > 16-bit TSRs are.
> > 
> > > And even then it might simply not be practical.  Better run your DOS 
> > > applications under dosemu and use standard BRLTTY.
> > 
> > I don't know what use the question was for, but one potential use is for
> > using DOS+brltty+loadlin as an accessible boot loader.
> 
> Well... for such a use I'd probably investigate linking BRLTTY directly 
> with grub instead.

That's quite another story, since grub doesn't provide all the features
that an OS provides.  It doesn't handle interrupts, for instance.
Porting brltty to DOS would probably be much easier.

I already did some work on grub1: I added the VisioBraille driver
to grub and added basic grub reading, and this already works quite
fine.  But grub people don't accept any new features in grub1.  Such
development would have to wait for grub2.

> That'd be much more powerful and wouldn't require 
> DOS at all.

More than that, it would be useful that brltty (and/or other screen
readers) be able to provide basic drivers + basic screen reading engine
as small independant objects.  That would even permit integration in
BIOSes (even in proprietary BIOSes if the object licence permits it (BSD
for instance, not GPL/LGPL))

Samuel