web analytics

Define port? Differentiate fixed port addressing and variable port addressing.

          Port : A port is an adapter which enables a system to communicate with its input/output devices. Using port user can connect I/O devices and use them. There various types of port such as parallel port, serial port etc.
            Differences Between Fixed Port and Variable Port Addressing


Fixed Port Addressing
Variable Port Addressing
Fixed port addressing is of 8-bit.
Variable port addressing is of 16-bit.
In this case, only the lower AX, that is, AL is used.
In this case, AX is used.
In personal computer we can not use fixed port addressing as all 16-bits must be used.
We use variable port addressing in personal computer.