tcl.chg-device Verb: Access/Tape Commands

tcl.chg-device

Command tcl.chg-device Verb: Access/Tape Commands
Applicable release versions: AP
Category Tape Commands (36)
Description changes a tape device.

Devices which can be used as tapes are listed by the "list-device" command. Some characteristics can be changed to either modify the behavior of a device or to replace a device by another one.

The changes made with this command are not permanent and are lost when the virtual machine is rebooted. If no option is specified, the current value is retained. The following options and values are recognized:

name=newname

This specifies a new device name. Since this is likely to completely change the device, all other options should be specified as well. Spaces are not allowed. The length of the new name cannot exceed 63 characters.

type=[floppy|halfinch|8mm|sct]

Specifies the type of device.

density=[360K|1.2M|1.44M|pseudo]

This specifies the density for a floppy. "pseudo" indicates an 'infinite' density device, such as pseudo floppy on hard disk.

density=[1600|3200|6250]

Specifies the density for a half inch device. This field is essentially for information purposes, since, on most Unix implementations, the density of the drive is encoded in the device name (as a suffix, for instance).

density=[low|standard|high]

Specifies the density for a SCT. This field is essentially for information purposes, since, on most Unix implementations, the density of the drive is encoded in the device name (as a suffix, for instance).

label=[80|512]

Specifies the label block size. Valid for 8mm tapes only. The Pick label is always 80 bytes long, but some Pick implementations write it in a 80 byte block, while AP writes it in a 512 byte block. To be able to exchange 8mm tapes between systems, it might be necessary to change this option.

blksize=default block size

Specifies the default block size. Usually, this is 16384 for Native systems, and 512 for hosted Unix systems.
Syntax chg-device device.number option=value { option=value ... }
chg-device ?
Options
Example
chg-device ?
USAGE: CHG-DEVICE devnum option=value {option=value ..}  {(option}
options:
name=newname
type=[ floppy | halfinch | 8mm | sct ]
density=[360K|1.2M|1.44M|pseudo] (floppy)
        [ 1600 | 3200 |6250 ]  (1/2 inch)
        [ low | standard | high ]   (sct)
label=[ 80 | 512 ]             (8mm only)
blksize=newblksize
 Displays the help.

chg-device 7 name=/tmp/pseudotp
Changes the name of the Unix file or pipe used as a pseudo tape.
Purpose
Related tcl.list-device
tcl.set-device
tcl.config.tape
tcl.t-select
tcl.t-stat
tcl.chg-device.link