TU(4)            NetBSD Programmer's Manual (VAX Architecture)           TU(4)

NNAAMMEE
     ttuu - VAX-11/750 TU58 console cassette interface

DDEESSCCRRIIPPTTIIOONN
     The ttuu 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.

FFIILLEESS
     /dev/tu0

DDIIAAGGNNOOSSTTIICCSS
     ttuu%%dd:: lloosstt rreeccvv iinntteerrrruupptt..
     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.

HHIISSTTOORRYY
     The ttuu driver appeared in 4.1BSD.
     A new driver showed up in NetBSD 1.1A.

BBUUGGSS
     The VAX-11/750 console interface is unuseable while the system is multi-
     user; it should be used only with the system running single-user and,
     even then, with caution.

4th Berkeley Distribution        June 5, 1993                                1