Question

How many output ports are there in peripheral I/O ?
1. 256
2. 512
3. 264
4. 24

Answer 1

Correct Answer - Option 1 : 256

The correct answer is 256.

• The input/output ports are addressed using special instructions such as IN for input and OUT for output.
• An 8-bit port address should be followed by the IN or OUT instruction mnemonic.
• An 8-bit address is assigned to each I/O device to identify it.
• There will be 2⁸ =256 input ports and 256 output ports are possible in an 8085-based microcomputer.
• The port number usually followed from 0–255.
• The device that receives data for processing is called an input device.
• The keyboard is the most frequent input device.
• Any hardware device that sends data from a computer to another device is referred to as an output device.
• The monitor is the most frequent output device.​