Byte code are bytes which represent instructions for the virtual machine to carry out. If you wanted the value 0x01 to tell the virtual machine to quit then you would likely have something like
Code:
if (Byte==0x01)
Quit();
To create the Byte code you might do something like this
Code:
if (!strcmpi(Command, "Quit"))
Byte=0x01;
The virtual machine would be an emulator if it was designed to do the job of a system which allready exists such as game console emulators which read in ROMs and try to proecess them in the same way the console dose.