#include <stdio.h>

int main(void) {
    printf("=== Simulating Canonical I/O Protocol ===\n");
    printf("Step 1: OS polls STATUS register until not BUSY\n");
    printf("  (in reality this loop wastes CPU)\n");
    printf("Step 2: OS writes data to DATA register (PIO)\n");
    printf("Step 3: OS writes command to COMMAND register\n");
    printf("Step 4: OS polls STATUS until complete\n");
    printf("I/O done. Using interrupts would overlap this wait with other computation.\n");
    return 0;
}