What is the primary drawback of Programmed I/O data transfer mode?

Subject: Computer Architecture and Organization

Topic: Input-Output (I/O) Organization & DMA

Options:

1. Option A: CPU wastes significant processing cycles constantly polling I/O status flags in a busy-wait loop
2. Option B: Requires high cost DMA controllers
3. Option C: Only works with optical storage
4. Option D: Causes hard drive corruptions

Correct Answer:

Option A: CPU wastes significant processing cycles constantly polling I/O status flags in a busy-wait loop

Explanation:

In Programmed I/O, the CPU remains trapped in a tight status-check loop (busy waiting) until the peripheral is ready, wasting CPU processing bandwidth.