The night watch who stopped rewinding the tape
In a little booth by the harbour, a guard watches one camera feed in the cold. Boats slide into view, then fog wipes them out. The guard keeps a notepad log so the night still makes sense. DNA is the footage, and the notepad is the small memory a computer carries forward.
A common DNA reader works like a guard who keeps rewinding. Each new bit gets checked by scanning back and comparing with loads of earlier bits. It can be sharp on short clips, but it gets slow and hungry for memory when the clip runs far longer than it was built for.
Caduceus and Hawk act more like the notepad guard. They move forward and keep updating a fixed-size summary, instead of replaying the whole tape. Ships are DNA letters, the log is the summary, and carrying it on keeps the reader oriented. Takeaway, a steady log helps on long runs.
On the usual clip length, the notepad style didn’t turn soft. Caduceus often matched or beat the rewind-style reader on several DNA jobs, like guessing activity signals and some control markers. Hawk was weaker on some tasks about the effect of tiny changes.
Then they stretched the clip far past what the rewind-style reader was used to, without special tuning. Caduceus stayed close to its earlier quality across tasks, and Hawk kept its scores steady on the tiny-change jobs. The rewind-style reader tended to slip badly once it left its comfort zone.
For a coastline-length shift, they chopped the DNA into chunks and passed the final notepad state into the next chunk, like handing the same logbook to the next guard. With that handoff, Hawk could handle about a million letters on one high-end chip and stay roughly steady. The odd bit was that more distance didn’t automatically mean better answers.