1.\" Copyright (c) 1980, 1991 Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)tu.4 6.2 (Berkeley) 03/27/91 7.\" 8.Dd 9.Dt TU 4 vax 10.Os BSD 4 11.Sh NAME 12.Nm tu 13.Nd 14.Tn VAX-11/730 15and 16.Tn VAX-11/750 17.Tn TU58 18console cassette interface 19.Sh SYNOPSIS 20.Cd "options MRSP" 21(for 22.Tn VAX-11/750 Ns 's 23with an 24.Tn MRSP 25prom) 26.Sh DESCRIPTION 27The 28.Nm tu 29interface provides access to the 30.Tn VAX 3111/730 and 11/750 32.Tn TU58 33console 34cassette drive(s). 35.Pp 36The interface supports only block 37.Tn I/O 38to the 39.Tn TU58 40cassettes. 41The devices are normally manipulated with the 42.Xr arff 8 43program using the ``f'' and ``m'' options. 44.Pp 45The device driver is automatically included when a 46system is configured to run on an 11/730 or 11/750. 47.Pp 48The 49.Tn TU58 50on an 11/750 uses the Radial Serial Protocol 51.Pq Tn RSP 52to communicate with the cpu over a serial line. This 53protocol is inherently unreliable as it has no flow 54control measures built in. On an 11/730 the Modified 55Radial Serial Protocol is used. This protocol incorporates 56flow control measures which insure reliable data transfer 57between the cpu and the device. Certain 11/750's have 58been modified to use the 59.Tn MRSP 60prom used in the 11/730. 61To reliably use the console 62.Tn TU58 63on an 11/750 under 64.Tn UNIX , 65the 66.Tn MRSP 67prom is required. For those 11/750's without 68an 69.Tn MRSP 70prom, an unreliable but often 71useable interface has been developed. 72This interface uses an assembly language ``pseudo-dma'' routine 73to minimize the receiver interrupt service latency. 74To include this code in 75the system, the configuration must 76.Em not 77specify the 78system will run on an 11/730 or use an 79.Tn MRSP 80prom. 81This unfortunately makes it impossible to configure a 82single system which will properly handle 83.Tn TU58 Ns 's 84on both an 11/750 85and an 11/730 (unless both machines have 86.Tn MRSP 87proms). 88.Sh FILES 89.Bl -tag -width /dev/tu0xx -compact 90.It Pa /dev/tu0 91.It Pa /dev/tu1 92(only on a 93.Tn VAX Ns \-11/730) 94.El 95.Sh DIAGNOSTICS 96.Bl -diag 97.It tu%d: no bp, active %d. 98A transmission complete interrupt was received with no outstanding 99.Tn I/O 100request. This indicates a hardware problem. 101.Pp 102.It "tu%d protocol error, state=%s, op=%x, cnt=%d, block=%d." 103The driver entered an illegal state. The information printed 104indicates the illegal state, operation currently being executed, 105the 106.Tn I/O 107count, and the block number on the cassette. 108.Pp 109.It "tu%d receive state error, state=%s, byte=%x." 110The driver entered an illegal state in the receiver finite 111state machine. The state is shown along with the control 112byte of the received packet. 113.Pp 114.It tu%d: read stalled. 115A timer watching the controller detected no interrupt for 116an extended period while an operation was outstanding. 117This usually indicates that one or more receiver interrupts 118were lost and the transfer is restarted (11/750 only). 119.Pp 120.It tu%d: hard error bn%d, pk_mod %o. 121The device returned a status code indicating a hard error. The 122actual error code is shown in octal. No retries are attempted 123by the driver. 124.El 125.Sh SEE ALSO 126.Xr arff 8 127.Sh HISTORY 128The 129.Nm 130driver appeared in 131.Bx 4.1 . 132.Sh BUGS 133The 134.Tn VAX Ns \-11/750 135console interface without 136.Tn MRSP 137prom is unuseable 138while the system is multi-user; it should be used only with 139the system running single-user and, even then, with caution. 140