The tape in the read bridge: the work being done nowPeg rack: the clipped tape ends are the stored statesA paper-tape telegraph relay desk. The read bridge cranks a tape through its sprocket hole by hole; the brass pegs hold the clipped end of every tape it has already read. When a new tape arrives, the comparator shuttle sweeps the pegs and the read pin resumes from the peg whose tape matches the new one longest — only the new tail ever sees the sprocket. Every token's state is 80 KB of tape, so a 15,000-token tape is 1.2 GB and the 2 GB rack holds about 25,000 tokens at most for a single tape. The sprocket cranks new tokens at 500 tok/s, while a resume off the pegs takes 0.3 s however long the match is; in the measured agent run 74% of prompt tokens came off the pegs.