t-select command

The t-select command attaches a tape device to the current process, but we recommend using the set-device TCL command.


 t-select {device.num} {,device.num}|{keyword}{(options}


device.num Can be expressed as a numeric literal. The device number must be a numeric integer between 0 and 15 and correspond to a predefined tape device.
3 3.5-inch floppy disk.
5 5.25-inch floppy disk.
9 9-track, 1/2-inch tape.
keyword Can be any combination of characters (except numeric integers between 0 and 15) displaying in the Type, Density, or Device Name columns of the t-stat command.

These keywords are used to pinpoint the preferred device from a captured list. On some systems there might be more than one of a particular device (two 5.25-inch floppy disks, for example). If there is not sufficient uniqueness in the parameters, the process always finds the first device.

options a 3.5-inch floppy disk.
b 5.25-inch floppy disk.
c For UNIX: Changes the 8mm tape block size. The current tape block size displays and the operator is prompted for the new block size (0 or 512). The default block size is set at 0 at install time. Zero means variable length.

For Windows: Changes the 8mm tape block size. The current tape block size displays and the operator is prompted for the new block size (0 or 512).

f Floppy disk (3.5-inch or 5.25-inch as default).
h High density (1.44 MB for 3.5-inch floppy disk, 1.2 MB for 5.5-inch floppy disk, 6250 bpi for 9-track tapes, 150 MB for 1/4-inch tapes).
i Suppresses display of devices after the command is complete (used in macros).
k Hard disk pseudo tapes are removable or fixed hard disks or regular host files. Their size is fixed and determined by the device or by the maximum file size for a user. The main usage for these devices is for small, fast t-dump/save, transaction logging, or incremental saves.
l Low density (720 KB for 3.5-inch floppy disk, 1600 bpi for 9-track tapes).
m Medium density (720 KB for 5.25-inch floppy disk, 3600 bpi for 9-track tapes).
n Network pseudo tape has an infinite size. It is assumed another system is reading the data at the other end of the network.
q 1/4-inch tape.
s Standard density (360 for 5.5-inch floppy disk, 60 MB or 120 MB for SCTs.
w Prevents an automatic rewind on the device. This option must be used to set the device to a floppy disk with an unformatted floppy disk in the drive.
x Default block size.


Tape devices include floppy disks, SCT, 1/2-inch, 2mm cartridge tape, 4mm DAT devices, and pseudo floppy disks, such as communication ports and intervirtual machine files.

The t-select command is the root command from which the set-floppy, set-sct, set-half, and set-device commands operate. If no options or parameters are specified, the t-select command displays all devices defined for the system and prompts for a selection.

For UNIX: If there is more than one floppy disk drive, and one of them is a 5.25-inch floppy disk, the 5.25-inch floppy disk is always designated as drive A. If no other parameters but Floppy are given, the command assumes drive A, 5.25-inch high density floppy disk. These devices are defined in the system configuration file. If a comma separates more than one device number, then they are linked together.

If the pseudo floppy does not exist, the t-select will prompt the user with "Device does not exist, create it?"


Assume the following device list for all examples:

 Tape Status
 # Type           Density          Device Name
 0 floppy         3-1/2" 1.44m     /dev/rfd0h
 1 floppy         3-1/2" 720k      /dev/rfd0l
 2 floppy         5-1/4" 1.2m      /dev/rfd1.15
 3 floppy         5-1/4" 360k      /dev/rfd1.9
 4 quarter inch   high (350m)      /dev/rmt2.1
 5 quarter inch   standard (120m)  /dev/rmt2.5
 6 floppy         infinite         /tmp/floppy

Example 1

Attaches the 3.5-inch low density floppy disk.

 t-select 1
 t-select floppy (b
 t-select 720k

Example 2

Attaches the pseudo floppy disk file called /tmp/floppy on a UNIX-based system.

 t-select 6
 t-select floppy infinite
 t-select /tmp/floppy