So MS-DOS on XP is like Java...
Not exaclty.
"Virtual Machine" has another meaning in this context. In the context of OSs, a Virtual Machine is some kind of systems that let the hosted application run in the processor directly, but traps every OS call. That means that when you run a MSDOS executable in Windows XP it runs directly on the processor, but whenever it does a "DOS call" (changing graphics mode, reserve memory, open a file, communicate to a port, etcetera) this call gets trapped by the Virtual Machine and the request is fulfilled by it.
Windows doesn't allow direct access to devices 'cause that's a security flaw. That's why old viruses could rip your hard disk off or burn your videocard, for example. When a MSDOS program attempts to access a device directly, the NTVDM traps the attemp and handles it consequently, many times thru' device emulation. That's why Future.lib had so many problems in Windows 2000, for example, 'cause the NTVDM handled the Vesa BIOS calls very faulty. The XP NTVDM performs somewhat better, and using VDMSound you get even better device emulation.
You shouldn't need to shut anything down unless you're making a malicious program (tsk, tsk), or you're adding in hardware device connections.
Aga: You forgot all those "OS"-es people are making, that are actually GUIs
Quote:Aga: You forgot all those "OS"-es people are making, that are actually GUIs
lol - i remember the good old days...
Oz~
They're still being made by a lot of people.. But most people finally realize it's GUI, not OS.
