concept demos

change sensor values and the classification rule, compare actual with expected output, and watch the test pass or fail.

send a symbol over a noisy link and let the same readings decide it three times: alone, averaged over five, averaged over ten. fewer wrong decisions, less speed.

find the secret face among sixteen: every answer shrinks the crowd, the shrinking is measured in bits, and the halving strategy shows why four questions are enough.

press copy and hang each generation on the wall: watch the analog picture fade copy by copy, then ask what a file would have done.

turn an analog photo into numbers: pick resolution and colour depth (down to the game boy's four greys), see the picture change, and watch the byte count grow.

the same two cuts for sound: choose sampling rate and bit depth, see the staircase on the wave, and hear what gets thrown away.

send symbols over a noisy channel, oscilloscope style: grow the alphabet, tune the window, inject a disturbance, and watch the error rate fight the throughput.

two clocks, slightly apart: watch the receiver’s sampling points wander out of the time slots until the message turns to garbage, then let a sync marker save it.

a receiver is already listening to a lit room: pick a preamble and a way to mark the end, then watch what it makes of your message. leave one out and see it miss, misfire or hang.

send a photo over a framed link: watch every symbol cross while headers, checks and retries consume time without growing the picture.

flip eight bits and watch the number appear: binary, decimal, hex, and the ascii character behind it.

write your own code words, send a word, and see every reading the receiver could pick. get the list down to one and you have built a code that works.

an 8×8 picture, one bit per pixel: paint and watch the bytes write themselves, edit the hex and paint with numbers, then break a byte and see the damage.

a real bitmap in a hex editor: header fields underlined, click a pixel to find its three bytes, then change a byte and watch the picture obey, or the viewer refuse.

make a photo brighter one addition at a time: step through a single pixel with its bits and carries, then let the machine do the other sixteen thousand in a blink.

switches in, lamps out: flip the inputs of a single gate, watch a half adder carry, chain eight full adders into a byte adder, and make two gates remember a bit.

a text, a key, and xor: the key flips the bits, the same key flips them back. give it a one-byte key and try all 256, or scramble the parrot with a short key and see what survives.

paste any text and watch it get packed as you type: repeats become pointers, frequent letters get short codes. one letter over and over squeezes to almost nothing; random letters grow.