The PET Transfer Protocol (PTP), more commonly known as Punter or Old Punter, is a protocol for file transfer developed ca. 1980 by Steve Punter for use with his PETBBS and BBS64 bulletin board system (BBS) software. The "PET" in the name comes from the Commodore PET computer.

Compared to other contemporary protocols PTP was quite slow and unreliable; it supported only 7-bit transfers and had an weak checksum algorithm. Nevertheless, it was widely used on Commodore PET and C64 based bulletin boards up until the release of its vastly superior successor, C1, in 1984.

See also

• C1
• Punter protocol (disambiguation)