1.\" $NetBSD: tu.4,v 1.16 2009/04/11 22:21:44 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. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)tu.4 8.1 (Berkeley) 6/5/93 31.\" 32.Dd June 5, 1993 33.Dt TU 4 vax 34.Os 35.Sh NAME 36.Nm tu 37.Nd 38.Tn VAX-11/750 39.Tn TU-58 40console cassette interface 41.Sh DESCRIPTION 42The 43.Nm tu 44interface provides access to the 45.Tn VAX-11/750 46.Tn TU-58 47console cassette drive. 48.Pp 49The interface supports only block 50.Tn I/O 51to the 52.Tn TU-58 53cassettes. 54The devices are normally manipulated with the 55.Xr dd 1 56program. 57.Pp 58The device driver is automatically included when a 59system is configured to run on an 11/750. 60.Pp 61The 62.Tn TU-58 63on an 11/750 uses the Radial Serial Protocol 64.Pq Tn RSP 65to communicate with the cpu over a serial line. 66This protocol is inherently unreliable as it has no flow 67control measures built in. 68.Sh FILES 69.Bl -tag -width /dev/tu0xx -compact 70.It Pa /dev/tu0 71.El 72.Sh DIAGNOSTICS 73.Bl -diag 74.It tu%d: lost recv interrupt. 75A timer watching the controller detected no interrupt for 76an extended period while an operation was outstanding. 77This usually indicates that one or more receiver interrupts 78were lost and the transfer is restarted. 79.El 80.Sh HISTORY 81The 82.Nm 83driver appeared in 84.Bx 4.1 . 85.br 86A new driver showed up in 87.Nx 1.2 . 88.Sh BUGS 89The 90.Tn VAX-11/750 91console interface is unusable 92while the system is multi-user, because interrupts 93occur at a very high priority level (spl7) and cannot be blocked with splbio. 94Use this driver only when the system is running single-user and, 95even then, with caution. 96