The
tu interface provides access to the VAX-11/750 TU-58 console cassette drive.
The interface supports only block I/O to the TU-58 cassettes. The devices are normally manipulated with the
dd(1) program.
The device driver is automatically included when a system is configured to run on an 11/750.
The TU-58 on an 11/750 uses the Radial Serial Protocol (RSP) to communicate with the cpu over a serial line. This protocol is inherently unreliable as it has no flow control measures built in.