User`s guide

ASSIGN

Physical device references are in the form of ddn or dd or, in the case of the extended-

device units, d or dnn.

Use of the Catch-All Device

The device you assign as the catch-all device should be an initialized device that

contains no data you want to preserve, such as a logical disk.

The catch-all device is useful in preventing command-ﬁle failure when:

• An unmounted output device has been associated with a logical name, and the

logical name is required by the command ﬁle. For example, if you reference LD3

and LD3 is not mounted, it will not go to the catch-all device.

• A device has not been assigned the proper logical name.

Catch-All Restrictions

• You must have generated support for extended device-units, to be able to use the

catch-all device.

• If you make a reference to a d or a dd unit that does not exist when d or dd is a

valid physical device, you will get an error, even if you have assigned the catch-

all device. A reference to a physical-device name with an invalid unit always

gives you an error. For example, if you have a DU device and you reference DU3

and there is no DU3, you will get an error.

Warning

Digital recommends you use as a catch-all device, one whose only purpose is to be

the catch-all device. You should not specify the DK or SY as the catch-all device. A

mistyped command could unexpectedly alter or delete data residing on DK or SY.

Examples

1. RT–11 uses the LS handler for serial-interface printers and the LP handler

for parallel-interface printers. However, by default RT–11 utilities send print

jobs to a device named LP. So, if your printer is a serial-interface printer,

you must logically associate the name LP with the LS handler by issuing the

following ASSIGN command before you use the PRINT command for the ﬁrst

time. Otherwise, the output to LP will be sent through the parallel-interface

handler:

.ASSIGN LS: LP:

The colons following the device names are optional.

2. The next command redeﬁnes the default storage device.

.ASSIGN DU1: DK:

If after executing this command you supply a ﬁle speciﬁcation in a command and

omit the device name, it now defaults to DU1. This does not affect the default

system device, SY.

4 RT–11 Command Descriptions