Visualize
Simulators
16 simulators for operating systems, networks, digital logic, computer architecture, discrete mathematics and machine learning. Change the inputs and step through them; each one also sits inside the lesson that teaches it.
CPU scheduling simulator
Simulate CPU scheduling with your own processes: FCFS, SJF, SRTF, priority and round robin, with a Gantt chart, waiting and turnaround times, and a comparison.
Page replacement simulator
Simulate page replacement step by step: FIFO, LRU and Optimal on your own reference string and frame count, with every hit, fault and evicted page shown.
Banker's algorithm simulator
Run the banker's algorithm step by step: the Need table, each Need ≤ Work check, the safe sequence or why there is none, and resource requests.
Disk scheduling simulator
Simulate disk scheduling on your own request queue: FCFS, SSTF, SCAN, C-SCAN, LOOK and C-LOOK, with the arm's path, every move's distance and the total.
Race condition simulator
Cause a race condition yourself: two threads add 1 to a shared counter one machine instruction at a time, in the order you choose. Then turn on a lock.
Truth table maker
Type a logic formula and get its full truth table: a column for every part, and whether it is a tautology, a contradiction or neither. Supports and, or, not, xor, →, ↔.
Gradient descent simulator
Watch gradient descent fit a line to points step by step: the line moving, the loss falling or exploding, and why the learning rate matters. Change it yourself.
K-means clustering simulator
Step through k-means clustering half a step at a time: assign each point to its nearest centroid, then move each centroid. Try other starts and other k.
Subnet calculator
Enter an IPv4 address and prefix to see it in binary with the network and host parts marked: network and broadcast addresses, host range, and equal subnets.
Sliding window simulator
Simulate reliable delivery step by step: stop-and-wait, Go-Back-N and Selective Repeat, with packets and ACKs you choose to lose and both sides' windows shown.
TCP congestion control simulator
Plot TCP's congestion window round by round: slow start, congestion avoidance, and the reaction to a timeout or three duplicate ACKs, in Tahoe or Reno.
Karnaugh map solver
Click cells of a 2-, 3- or 4-variable Karnaugh map to set 1, 0 or don't care, and get the smallest sum of products with every group marked on the map.
Flip-flop simulator
Simulate D, T, JK and SR flip-flops clock by clock: type the inputs for each clock and watch Q change only on the clock edge, in a timing diagram and a table.
Ripple-carry adder
Add two binary numbers with a chain of full adders, bit by bit from the right, each passing its carry on. Shows unsigned and two's complement meaning and overflow.
Cache simulator
Simulate a CPU cache on your own address list: tag, set and offset bits, every hit and miss, and LRU replacement in direct-mapped and set-associative caches.
5-stage pipeline simulator
Fill in a 5-stage pipeline diagram cycle by cycle: one row per instruction, with the stalls a data hazard causes, with or without forwarding.