mu.4

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)mu.4	8.1	9/11/90
.TH mu 4 VAX
.SH Name
mu \- TM78/TU78/9 magnetic tape interface
.SH Syntax
.B master mt0 at mba? drive ?
.br
.B tape mu0 at mt0 slave 0
.SH Description
.NXR "TM78 magnetic tape interface"
.NXR "TU78 magnetic tape interface"
.NXS "mu interface" "TM78 magnetic tape interface"
.NXS "mu interface" "TU78 magnetic tape interface"
.NXS "mt file" "TM78 magnetic tape interface"
.NXS "mt file" "TU78 magnetic tape interface"
Prior to Version 2.0, this device was referenced by 
.MS mt 4 .
.PP
The TM78/TU78/9 combination provides a standard tape drive
interface as described in
.MS mtio 4 .
Only 1600 and 6250 bpi are supported; the
TU78/9 runs at 125 ips and autoloads tapes.
.SH Restrictions
Only the raw tape is supported.
.SH Diagnostics
\fBmu%d: no write ring\fR.
.br
An attempt was made to write on the tape drive when no write ring
was present.
.PP
\fBmu%d: not on line\fR.
.br
An attempt was made to access the tape while it
was off line.
.PP
\fBmu%d: hard error bn%d\fR.
.br
A tape error occurred at block \fIbn\fR.
When possible, the driver will have retried
the operation that failed several times before reporting the error.
Additional register information may be gathered from the system
error log file,
.PN /usr/adm/syserr/syserr.<hostname>.
.PP
\fBmu%d: blank tape\fP.
.br
An attempt was made to read a blank tape (a tape without even
end-of-file marks).
.PP
\fBmu%d: off line\fP.
.br
During an I/O operation, the device was set off line.
.SH Files
/dev/rmt???
.br
/dev/nrmt???
.SH See Also
mtio(4), nbuf(4), MAKEDEV(8), uerf(8)