Why DOS doesn't support protected-mode programming ?

[HypnotiC]

please, can any one tell me , Why DOS doesn't support protected-mode programming ?

Thanks

[Thingol]

Why DOS doesn't support protected-mode programming ?

You're saying good old MS-DOS (and the similar things like DR-DOS, FreeDOS etc)? MS-DOS supports anything because it does almost anything (MS-DOS is not a true operating system at all...). If you simply don't load any driver like EMM386 you can do anything that you want, including starting to program in protected-mode. It's the thing that the DOS Extenders (like Phar-Lap) do everyday.

[indiocolifa]

yes, don't your remember ...

DOS4GW Protected Mode RunTime v.xxx
(c) 1995 ... blahblah

running DOOM II ?