How to Build Latches and Memory with Project Red

RS Latch and Toggle Latch

An RS Latch has set and reset inputs and holds its output until the opposite input is pulsed. Pulse set to turn it on; it stays on until reset is pulsed. A Toggle Latch flips its state each time its single input is pulsed, so one button press turns it on and the next turns it off. Both are essential for turning a momentary signal into a lasting one, like a button that keeps a door open.

Transparent Latches

Transparent Latches work like a normal latch but let you see the internal state through the block, which helps when debugging. The Transparent Latch Cell is the cell-based version, useful inside compact cell circuits. Use these when you need to inspect state without opening an interface. Wire the set and reset inputs to your control signals and the output to whatever the latch should control.

Cells vs Gates

Project Red offers both gate versions and cell versions of many logic blocks. Cells are designed to sit in tight arrays and connect to bundled wiring, while gates are standalone blocks. For memory, a State Cell or RS Latch works well on its own; for dense builds, use the cell variants and route them with bus components. Always test a latch by pulsing set and reset separately and watching a lamp on the output before integrating it into a larger machine.