Re: [AD] [DOS] Win2k mouse bug

[Javier Gonzalez <xaviergonz@xxxxxxxxxx>]

I would say right now there are more chances to see an allegro user using
Win2K than WinNT (and in general, games). So i would go with Win2K
support...
My two cents

> I may look a little maniac about Win2k ;-) but some time ago Vincent and I
> came across the following problem: the mouse doesn't work under Win2k.
>
> There are three mouse drivers in the DOS port:
> - the 'mickeys' driver that uses relative position data supplied by int33h
> (default),
> - the 'int33' driver that uses absolute position data supplied by int33h,
> - the 'polling' driver that periodically polls (!) the mouse via int33h.
>
> The two first drivers uses a real-mode callback (RMCB) function registered
> through int33h, whereas the third driver doesn't.
> Now it's a well known fact that RMCBs are broken under Windows NT4.
> Therefore, if Windows NT is detected, Allegro simply refuses to use the
two
> first drivers and switches to the third one. But Vincent found that this
> third driver doesn't work on his Win2k box. And as Win2k is reported as
> Windows NT by Allegro, we are deadlocked.
>
> But hope can sometimes come from unexpected place ;-) since the RMCB bug
is
> fixed in Win2k; so the first driver does work under Win2k.
>
> Therefore the solution would be to use the 'mickeys' driver under Win2k
and
> the 'polling' driver under WinNT4. Unfortunately, although the guys from
> comp.os.msdos.djgpp have been trying to find it for more than one year,
> there is currently *no* way of telling Win2k from WinNT4 in a DOS program.
>
> So we're apparently stuck.
> Any suggestion ?
>
> --
> Eric Botcazou
> ebotcazou@xxxxxxxxxx
>
>