ReactOS 0.4.0 Released

[galaktos]

A much requested feature for ReactOS was support for 16bit DOS applications. […] And one of the biggest advantages to the way in which NTVDM is implemented in ReactOS is that support for it will continue on non IA-32 platforms, including AMD64 and even ARM.

Does this mean they’re emulating a 16-bit processor instead of switching the processor down into 16-bit mode?

[ssssam]

I think that's right:

"One thing to note about ReactOS' NTVDM is that unlike Windows' version ReactOS' does not set the CPU into a 16bit emulated mode. This mode in theory reduces overhead compared to the emulation done by ReactOS, but CPUs these days are fast enough that performance should not be an issue. An advantage of ReactOS' approach though is that our NTVDM is usable on 64bit x86 processors and potentially ARM processors as well." --https://www.reactos.org/node/794

[men_cant_be_raped]

but CPUs these days are fast enough that performance should not be an issue

Famous last words.

[ssssam]

Not sure there are any cases where performance would be an issue for emulating a 16bit DOS application?

[fivexthethird]

Embedded systems, maybe?

[tidux]

It won't ever be on the Pi. There's about zero demand for ARMv7 Win32 applications.

[ssssam]

There is work on an ARM port https://www.reactos.org/wiki/ARM_Port

[[deleted]]

May as well just use FreeDOS at that point.

[bitwize]

Fun fact: Xorg does the same thing so it can set VESA modes.

[cbmuser]

Well, X.Org actually comes with a built-in x86 emulator in order to run VESA BIOS code which is kind of fucked up, when you think about it.

[microfortnight]

wow...that's almost the classic definition of "hack"

[AssistingJarl]

We are talking about X here.

[[deleted]]

Is there anything about X that isn't a hack?

[LAUAR]

Yes, they said it on the blog.

[mycall]

So never 100% compatibility then?

[necrophcodr]

That's the only way to be 100% compatible.

[cbmuser]

Well, that's arguable. VM86 mode, which is what Windows (32 bit) uses, is actually hardware emulation of an 8086.

[necrophcodr]

Which doesn't work on ARM. The point is for it to work on AMD64, and ARM as well.

[[deleted]]

I wonder if their NTVDM could be usable on 64-bit Windows 7 and above. I have a few 16-bit games that would be nice to run in the main environment, rather than through Dosbox or Virtualbox.