1.\" $NetBSD: tu.4,v 1.11 2001/09/11 22:52:57 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 TU58 44console cassette interface 45.Sh DESCRIPTION 46The 47.Nm tu 48interface provides access to the 49.Tn VAX 5011/750 51.Tn TU58 52console cassette drive. 53.Pp 54The interface supports only block 55.Tn I/O 56to the 57.Tn TU58 58cassettes. 59The devices are normally manipulated with the 60.Xr dd 1 61program. 62.Pp 63The device driver is automatically included when a 64system is configured to run on an 11/750. 65.Pp 66The 67.Tn TU58 68on an 11/750 uses the Radial Serial Protocol 69.Pq Tn RSP 70to communicate with the cpu over a serial line. This 71protocol is inherently unreliable as it has no flow 72control measures built in. 73.Sh FILES 74.Bl -tag -width /dev/tu0xx -compact 75.It Pa /dev/tu0 76.El 77.Sh DIAGNOSTICS 78.Bl -diag 79.It tu%d: lost recv interrupt. 80.br 81A timer watching the controller detected no interrupt for 82an extended period while an operation was outstanding. 83This usually indicates that one or more receiver interrupts 84were lost and the transfer is restarted. 85.El 86.Sh HISTORY 87The 88.Nm 89driver appeared in 90.Bx 4.1 . 91.br 92A new driver showed up in 93.Nx 1.2 . 94.Sh BUGS 95The 96.Tn VAX Ns \-11/750 97console interface is unuseable 98while the system is multi-user, because interrupts 99occur at a very high priority level (spl7) and cannot be blocked with splbio. 100Use this driver only when the system is running single-user and, 101even then, with caution. 102