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Memory & Registers

A plain gate forgets the instant the input changes. But loop its output back into its own input and it holds — it remembers the last thing you told it. That loop is a latch, and a register is just a row of them.

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Set / Reset

Press Set and let go — the bit stays 1. The feedback loop keeps holding it until you Reset. That memory of 0 survives with no button held down.

A 4-bit register

Four latches side by side hold any value: 1011 = 11. Tap a bit to flip the latch under it.

SR latch — two cross-coupled NOR gates

Each NOR gate feeds the other. That loop is what holds the bit — no clock, no power switch held down.

Register strip

= 11

Memory isn't a new kind of part — it's gates wired in a loop so they hold their own answer. A register is just a row of them.