Disk Scheduling: FCFS, SSTF, SCAN & C-SCAN (2D)

Every operating system keeps a queue of pending disk I/O requests, and the order it services them in is governed by a disk-scheduling algorithm — one of the classic mechanisms an OS kernel uses to turn "what the programs asked for" into "what the hardware actually does." This 2D simulator draws a real cylinder track as a number line: a read/write head sweeps toward a queue of pending requests under First-Come-First-Served, Shortest-Seek-Time-First, SCAN or C-SCAN, servicing each request in the algorithm's genuinely computed order. Switch algorithms on the same request queue to see how total head movement — and therefore total seek time — changes, watch requests turn from pending amber to serviced green as the head reaches them, read live total and average seek-length numbers as the sweep runs, and use Compare mode to see all four algorithms' real total-distance results on the same queue, side by side in a bar chart.