Does 16 bit work yet on a 64 bit windows 10 OS?

Petey7 said:

Technically, when its in 32-bit mode (which is the same thing as "legacy mode" which I mentioned before) its not natively running 16-bit code either. Its being run through NTDVM.

You are confusing the term "virtual machine" with "emulation". NTVDM does not "emulate" 16 bit applications, in that it is not interpreting code programmatically. It is running the code "natively", but doing so in a 'virtualized' environment.

When running software such as DOSbox, IIRC, then the code is actually interpreted and completely emulated. This is not "native" because the CPU is not executing the instructions natively.

groze said:

Can you explain something Mystere in a little more detail. I do know some of the answer or at least I think do. How come you can install a Windows 32 bit operating system on a 64 bit machine and run both 32 bit and 16 bit applications if the processor doesn't support it?

You're not really listening. I said quite clearly above "incapable of natively running 16 bit applications when running 64 bit operating systems". That part is important. The CPU is very capable of running 32 bit and 16 bit applications, but NOT when running in 64 bit mode (which is what happens when you have a 64 bit OS).

Mystere said:

You're not really listening. I said quite clearly above "incapable of natively running 16 bit applications when running 64 bit operating systems". That part is important.

The CPU is very capable of running 32 bit and 16 bit applications, but NOT when running in 64 bit mode (which is what happens when you have a 64 bit OS).

I assume you mean it is the operating system that tells the cpu what mode to use. Otherwise, you wouldn't be able to run 32 bit operating systems on a 64 bit machine.

groze said:

I assume you mean it is the operating system that tells the cpu what mode to use. Otherwise, you wouldn't be able to run 32 bit operating systems on a 64 bit machine.

Not exactly, it's the bootstrapper that initializes the CPU in either 64 bit or 32 bit mode on startup, once in that mode it must either load a 64 bit OS or 32/16 bit OS respectively (a 32 bit OS cannot run in 64 bit mode, and a 64 bit OS cannot run in 32 bit mode). Once the 64 bit OS is running, it can run 32 bit applications in the SysWOW64 layer (Wow stands for Windows on Windows, a sort of virtualized Windows running within Windows using the x86-64 ability to virtualize 32 bit applications in 64 bit mode). But it cannot run 16 bit applications. Once a 32 bit OS is running, it can virtualize 16 bit applications, but not 64 bit apps.

So think of it as the OS can only run the "bitness" of one level lower than it, and that's how the CPU itself works.