Solution

The correct answer is A, B and D Only.

Key Points

• Programmed I/O: This is a technique where the CPU is in direct control of the I/O operations. It waits for the I/O operation to complete, which can make the CPU idle for a significant amount of time.
• Interrupt-driven I/O: In this method, the CPU can execute other instructions while an I/O operation is in progress. When the I/O operation is complete, an interrupt is generated to inform the CPU.
• Direct Memory Access (DMA): This technique allows certain hardware subsystems to access main system memory independently of the CPU. It is used to transfer data directly between I/O devices and memory without continuous CPU intervention.

Additional Information

• Rotational I/O: This term does not correspond to a recognized I/O technique in the context of computer architecture. It might be a confusion with rotational latency, which is a term related to the time it takes for the desired sector of a disk to rotate under the read-write head.
• Channelized I/O: This is an I/O technique used in mainframes where dedicated I/O channels handle the I/O operations. Although it is a valid I/O technique, it is less commonly discussed in the context of general computing compared to the other options.