Emil Post's tag system as a demand rate ugen - Buffer version.
Full arguments description and more explanations, see Dtag
a 1-channel buffer - when its size is reached, the process ends (dependent on mode). Theoretically, tag systems have an infinite tape size - practically, one may want to try different finite sizes. Any number of tag processes may run concurrently on a single buffer, overwriting each other's output. While not very expressive, this may have interesting results.