Re: 4DOS is now free - those who use Windows NT/2K/XP and dos based emulators

[samir.ribic@alemsistem.com.ba (Samir Ribic)]

"Brian Gaff" <Briang1@blueyonder.co.uk> wrote in message news:<LZi7d.950$xb.642@text.news.blueyonder.co.uk>...
> What someone needs to do is write a Dos that will run on xp!
> 
If you speak about 32 bit XP,  is not command prompt of XP already DOS
that runs on XP? You can start the most of DOS programs except:

1) Programs that directly access hardware (usualy LPT ports,  sound
cards, disks). However, direct access to video memory, keyboard, COM
ports and PC speaker is generally O.K.

2) Timing dependant programs. Preemtive multitasking has penalty  that
no such program can cope with. Try BEEP 10,0 on any Spectrum emulator
for DOS running under NT/2000/XP. The tone will be harsh.

3) Programs that use special memory extenders. Conventional memory is
well emulated, but extended memory often conflicts with XP.

For kind 1) there are some solutions, like VDMSOUND and similar
programs. Kind of problem 3) is solvable with different version of the
extender (which BTW, are not part of the DOS). And no DOS emulator can
solve problem 2) anyway.

But 64 bit XP can not start DOS programs at all.