Minecraft wiki entry for Redstone_computers, associated text: The RAM in the first case is utilizing the locking redstone repeaters with the correct timing. This requires a bit of a plan but is very space-efficient. The conversion of a bus to the lines in order to lock the redstone repeaters also requires setting timings. This is time-consuming, much more than the registers, however, it is very compact and efficient. The address bus (green) would turn in binary to unlock a certain byte, either to be read or set by the control bus (second line, on the left).