1.\" $NetBSD: tu.4,v 1.13 2003/04/06 19:44:01 wiz Exp $ 2.\" 3.\" Copyright (c) 1980, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" from: @(#)tu.4 8.1 (Berkeley) 6/5/93 35.\" 36.Dd June 5, 1993 37.Dt TU 4 vax 38.Os 39.Sh NAME 40.Nm tu 41.Nd 42.Tn VAX-11/750 43.Tn TU-58 44console cassette interface 45.Sh DESCRIPTION 46The 47.Nm tu 48interface provides access to the 49.Tn VAX-11/750 50.Tn TU-58 51console cassette drive. 52.Pp 53The interface supports only block 54.Tn I/O 55to the 56.Tn TU-58 57cassettes. 58The devices are normally manipulated with the 59.Xr dd 1 60program. 61.Pp 62The device driver is automatically included when a 63system is configured to run on an 11/750. 64.Pp 65The 66.Tn TU-58 67on an 11/750 uses the Radial Serial Protocol 68.Pq Tn RSP 69to communicate with the cpu over a serial line. This 70protocol is inherently unreliable as it has no flow 71control measures built in. 72.Sh FILES 73.Bl -tag -width /dev/tu0xx -compact 74.It Pa /dev/tu0 75.El 76.Sh DIAGNOSTICS 77.Bl -diag 78.It tu%d: lost recv interrupt. 79.br 80A timer watching the controller detected no interrupt for 81an extended period while an operation was outstanding. 82This usually indicates that one or more receiver interrupts 83were lost and the transfer is restarted. 84.El 85.Sh HISTORY 86The 87.Nm 88driver appeared in 89.Bx 4.1 . 90.br 91A new driver showed up in 92.Nx 1.2 . 93.Sh BUGS 94The 95.Tn VAX-11/750 96console interface is unusable 97while the system is multi-user, because interrupts 98occur at a very high priority level (spl7) and cannot be blocked with splbio. 99Use this driver only when the system is running single-user and, 100even then, with caution. 101