RTC application VB

Some body knows how to use RTC using VB - C#??

I´doing the access using PhisicalAddressPointer function, but it doesn´t
work.

uint Rtc = 0x5700007b; //hour address
uint PortBDataSize = 0x1;

PhysicalAddressPointer RTC = new PhysicalAddressPointer(Rtc,
PortBDataSize);

uint rtc = (uint) RTC.ReadInt32();


thank´s..