Moon Joker

Moon Joker — Digital Logic Workbench Wire real circuits. Watch real signals move through them. Find out exactly how fast your design can run. Moon Joker is a hands-on workbench for digital logic. Place gates, flip-flops and small blocks on a board, wire them up, and press play — then watch values propagate with honest delays, one event at a time or at full speed. Every number here is computed from the circuit you built. Nothing is a stored answer. BUILD AND SIMULATE Drop parts from a picker grouped by family — sources, gates, blocks, flip-flops and probes — and feed one output to as many inputs as you like. While a run is going, each wire carries the colour of its value: green for 1, dim violet for 0, hatched amber for unknown, red where two outputs fight over one net. Tap a switch mid-run and watch the change ripple outward. Step one event at a time to see the smallest move the simulation can make, or step one clock edge at a time to walk a clocked circuit cycle by cycle and watch every flip-flop take its sample. READ THE WAVEFORM Every run records a trace you can read like a scope. Value bands for 0 and 1, hatched bands for unknown, markers where a narrow pulse appeared, and pins on the axis wherever a setup or hold time was broken — each with the margin it missed by. Two draggable cursors measure the time between any two points. Zoom, pan, and jump straight to the next recorded change. MEASURE THE TIMING Run the analysis and get the numbers that matter: the highest frequency every register-to-register path can still meet, the slack on every endpoint, a hold check that uses the fastest path rather than the slowest, and the worst paths ranked tightest to loosest. Open any one for a full waterfall — every element in order, its delay, the running total — plus a plain sentence naming the part family eating most of the path. DERIVE THE TRUTH TABLE For a combinational circuit, the app enumerates every input combination, settles each one, and builds the exhaustive truth table. Then it reduces each output to its minimal sum-of-products expression and prices that against the circuit you actually built, so you can see what your design costs versus what it could. TAKE ON FIFTEEN TRIALS Three chapters of timed design challenges — gates, arithmetic and decode, memory — each with fixed pins, allowed parts, and a cost and delay budget. Build something that hits the specified behaviour, then verify it: every input vector is checked, or every cycle of a clocked sequence. Pass and you earn a score with bronze, silver or gold, itemised so you can see exactly what your area and your delay each contributed. Fail and you get the precise vector that broke, expected beside actual. RUN PROGRAMS THROUGH A PIPELINE Write a small assembly program, choose the microarchitecture — forwarding, branch prediction, where branches resolve, memory ports, register timing — and run it. You get a cycle-by-cycle stage diagram with every bubble and every flushed instruction drawn in place, a hazard log naming the producer, the consumer, the register and the cycles lost, and the honest summary: cycles per instruction. Then compare all twenty-four configurations at once and see which single change buys you the most. MADE FOR LEARNING IT PROPERLY Choose datasheet delays, where every part carries its own per-pin number, or unit delays, where the shape of the path is the whole story. Switch between absorbing narrow pulses the way a real gate does and showing every spike unequal paths produce. A built-in handbook explains how to work the bench and what each number means — slack, fmax, how trials are scored, where pipeline cycles go. Attach a photo of a whiteboard sketch to any circuit for reference, and export a card of your finished design straight to your gallery. Studying computer architecture, teaching it, brushing up before an interview, or just curious what happens between a clock edge and an answer? Build it and see for yourself.