why 64-bit OS cannot run 16bit application?

[Jun Wei Goh]

why 64bit os cant run 16 bit application. Shouldn't it work ? Is like having 64 pencils and all you need is 16 pencil right? i hope someone can explain

[vanished]

tbh I'm not sure either... it feels like laziness more than a technical limitation.  I don't see why they couldn't layer WOW64 and WOW16, or just build in an emulator, etc.  Surely any thing that's 16 bit could be emulated sufficiently fast in this day and age on modern hardware.

[Master Disaster]

14 minutes ago, Ryan_Vickers said:

tbh I'm not sure either... it feels like laziness more than a technical limitation.  I don't see why they couldn't layer WOW64 and WOW16, or just build in an emulator, etc.  Surely any thing that's 16 bit could be emulated sufficiently fast in this day and age on modern hardware.

Still wouldn't work, PCs have changed so much over this time period and old apps and games expect certain things to exist inside the architecture that simply don't exist anymore. Emulation is great but it's not a magic solution that can fix any issues.

[vanished]

Just now, Master Disaster said:

Still wouldn't work, PCs have changed so much over this time period and old apps and games expect certain things to exist inside the architecture that simply don't exist anymore. Emulation is great but it's not a magic solution that can fix any issues.

I think it could... I mean that's literally the whole point of emulation.  You simulate exactly what they're expecting, so you can fix any issues.

[BlueChinchillaEatingDorito]

If I were to give you my best guess, it's so developers don't have to waste time fixing compatibility issues that arise from running such outdated software on a updated OS. Even moving between x64 OSes like Windows Vista, to 7, to 8, to 8.1, and to 10 (which are pretty similar underneath, not completely) would require some applications to be patched to get working correctly. So you could imagine if we keep supporting 16-bit, and 32-bit applications, the overhead is enormous to keep these outdated applications alive. It's only a matter of time support for 32-bit is also out the door. 

 

It could also be deprecation of older instruction sets that 16-bit applications need, but I could be wrong as that is way before my time and it was just a wild guess that may not be too far off. You see things like this in Java where some things in Java 7 have been deprecated and are no longer supported in Java 8. 

[Master Disaster]

Just now, Ryan_Vickers said:

I think it could... I mean that's literally the whole point of emulation.  You simulate exactly what they're expecting, so you can fix any issues.

I guess your right, the answer is probably more to do with do they want to rather than can they.

[asus killer]

i saw a video once about this, i think there are changes to the libraries (dll and stuff) and actual physical changes to the CPU that prevent this.

[rentaspoon]

1 hour ago, Jun Wei Goh said:

why 64bit os cant run 16 bit application. Shouldn't it work ? Is like having 64 pencils and all you need is 16 pencil right? i hope someone can explain

Technically cheating but you can ww.groovypost.com/howto/enable-16-bit-application-support-windows-10/amp/

 

Tldr: they don't have the 16bit sub system so you have to run either a 32bit system or virtual machine a 64bit