TU(4)                  OpenBSD Programmer's Manual (VAX)                 TU(4)

NAME
     tu - VAX-11/750 TU58 console cassette interface

DESCRIPTION
     The tu interface provides access to the VAX 11/750 TU58 console cassette
     drive.

     The interface supports only block I/O to the TU58 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 TU58 on an 11/750 uses the Radial Serial Protocol (RSP) to communi-
     cate with the cpu over a serial line.  This protocol is inherently unre-
     liable as it has no flow control measures built in.

FILES
     /dev/tu0

DIAGNOSTICS
     tu%d: lost recv interrupt.
     A timer watching the controller detected no interrupt for an extended pe-
     riod while an operation was outstanding.  This usually indicates that one
     or more receiver interrupts were lost and the transfer is restarted.

HISTORY
     The tu driver appeared in 4.1BSD.
     A new driver showed up in NetBSD 1.1a.

BUGS
     The VAX-11/750 console interface is unusable while the system is multi-
     user; it should be used only with the system running single-user and,
     even then, with caution.

OpenBSD 3.0                     March 27, 1991                               1
