Bring man page into closer correspondance with current reality. Tweaks by

jmc@.

ok beck@ jmc@

1 files changed, 41 insertions, 64 deletions

diff --git a/share/man/man4/st.4 b/share/man/man4/st.4
index 44051efbb42..9b019e5b265 100644
--- a/share/man/man4/st.4
+++ b/share/man/man4/st.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: st.4,v 1.11 2005/09/11 23:25:59 krw Exp $
+.\"	$OpenBSD: st.4,v 1.12 2006/06/01 05:55:32 krw Exp $
 .\"	$NetBSD: st.4,v 1.2 1996/10/20 23:15:24 explorer Exp $
 .\"
 .\" Copyright (c) 1996
@@ -70,7 +70,7 @@ adapter is probed during boot, the
 .Tn SCSI
 bus is scanned for devices.
 Any devices found which answer as
-.Sq Em Sequential
+.Em Sequential
 type devices will be attached to the
 .Nm
 driver.
@@ -78,9 +78,9 @@ driver.
 The
 .Nm
 driver is based around the concept of a
-.Dq Em mount session ,
+.Em mount session ,
 which is defined as the period between the time that a tape is
-mounted, and the time when it is unmounted.
+mounted and the time when it is unmounted.
 Any parameters set during a mount session remain in effect for the remainder
 of the session or until replaced.
 The tape can be unmounted, bringing the session to a close in several ways.
@@ -88,74 +88,49 @@ These include:
 .Bl -enum
 .It
 Closing an
-.Dq unmount device ,
-referred to as sub-mode 00 below.
-An example is
-.Pa /dev/rst0 .
+.Dq unmount device .
 .It
 Using the
 .Dv MTOFFL
 .Xr ioctl 2
 command, reachable through the
-.Sq Cm offline
+.Cm offline
 command of
 .Xr mt 1 .
-.It
-Opening a different mode will implicitly unmount the tape, thereby
-closing off the mode that was previously mounted.
-All parameters will be loaded freshly from the new mode.
-(See below for more on modes.)
 .El
-.Sh MODES AND SUB-MODES
-There are several different
-.Sq operation
-modes.
-These are controlled by bits 2 and 3 of the minor number
-and are designed to allow users to easily read and write different
-formats of tape on devices that allow multiple formats.
-The parameters for each mode can be set individually by hand with the
-.Xr mt 1
-command.
-When a device corresponding to a particular mode is first
-mounted, the operating parameters for that mount session are copied
-from that mode.
-Further changes to the parameters during the session will change those in
-effect for the session but not those set in the operation mode.
-To change the parameters for an operation mode, one must compile them into the
-.Dq Em quirk
-table in the driver's source code.
+.Sh EJECT and REWIND
+Bit 0 of the minor number specifies whether a rewind is attempted when the
+device is closed.
+When it is set, the device will not attempt a rewind on close
+and the device will have an
+.Sq n
+in its name.
+For example,
+.Pa /dev/rst0
+will rewind on close but
+.Pa /dev/nrst0
+will not.
 .Pp
-In addition to the operating modes mentioned above, bits 0 and 1
-of the minor number are interpreted as
-.Sq sub-modes .
-The sub-modes differ in the action taken when the device is closed:
-.Bl -tag -width XXXX
-.It 00
-A close will rewind the device; if the tape has been written, then
-a file mark will be written before the rewind is requested.
-The device is unmounted.
-.It 01
-A close will leave the tape mounted.
-If the tape was written to, a file mark will be written.
-No other head positioning takes place.
-Any further reads or writes will occur directly after the last
-read, or the written file mark.
-.It 10
-A close will rewind the device.
-If the tape has been written, then a file mark will be written before the
-rewind is requested.
-On completion of the rewind an unload command will be issued.
-The device is unmounted.
-.It 11
-Reserved.
-Currently unused.
-.El
+Bit 1 of the minor number specifies whether an eject is attempted when the
+device is closed.
+When it is set, the device will attempt to eject its media on close
+and the device will have an
+.Sq e
+in its name.
+For example,
+.Pa /dev/erst0
+will eject its media on close but
+.Pa /dev/rst0
+will not.
+.Pp
+There is no guarantee that the attempted eject or rewind will be supported
+by the actual hardware.
 .Sh BLOCKING MODES
 .Tn SCSI
 tapes may run in either
-.Sq Em variable
+.Em variable
 or
-.Sq Em fixed
+.Em fixed
 block-size modes.
 Most
 .Tn QIC Ns -type
@@ -226,7 +201,7 @@ to quickly and conveniently recognize and deal with brands and
 models of drive that have special requirements.
 .Pp
 There is a table (called the
-.Dq Em quirk table )
+.Em quirk table )
 in which the identification strings of known errant drives can be stored.
 Alongside each is a set of flags that allows the setting
 of densities and blocksizes for each of the modes, along with a
@@ -326,13 +301,15 @@ devices).
 .Sh FILES
 .Bl -tag -width /dev/[e][n][r]st[0-9] -compact
 .It Pa /dev/[e][n][r]st[0-9]
-general form
+General form.
 .It Pa /dev/rst0
-Mode 0, rewind on close
+No eject, rewind on close.
 .It Pa /dev/nrst0
-Mode 2, No rewind on close
+No eject, no rewind on close.
 .It Pa /dev/erst0
-Mode 3, Eject on close (if capable)
+Eject, rewind on close.
+.It Pa /dev/enrst0
+Eject, no rewind on close.
 .El
 .Sh SEE ALSO
 .Xr mt 1 ,