On Sunday, July 26, 2015 at 11:42:59 AM UTC-4, Peter Easthope wrote:
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.

What exactly are you tring to do? If you are using Windows, you should be able to disable it using the device manager.