DIYbanter - View Single Post - disablement and enablement of a computer serial port.

M Philbrook

In article ,
says...

Can anyone explain how a computer serial port is disabled and enabled? Many Web pages cover the software topics but I've found nothing explaining how a BIOS disables a port. Is is done by clearing any interrupt assignment to the port? Is the power to the UART shut off? Other ways? Probably more than one technique has been used but not a large number.

Can anyone cite a Web page which answers this?

Thanks, ... Peter E.

if Bios has control of it, it simply flips a bit
in a device manager chip on the board..

From that point, the OS does not see that serial port.

Which also means, there is no IRQ assigned to it or
port addresses etc.. in otherwords, no resources assigned
to it.

USB serial ports are a different story..

Jamie