Owner`s manual

Page 6-4 Chapter 6

6.4DEFINING DEVICES (DEVTBL)

Following the TRMDEF command lines is the DEVTBL command. It defines the

devices your computer can access. You must always have at least one DEVTBL

command line in the system initialization command file.

The computer already knows the System Disk, DSK0:, is present, so don’t put DSK0: in

the DEVTBL command line. If your computer has no devices other than DSK0:, enter

DEVTBL alone on a line, and do not follow it with any arguments.

You can list sharable and non-sharable devices on separate DEVTBL lines, or you can

list them together on the same DEVTBL line. A sharable device is one that all users can

access simultaneously, such as a disk drive. A non-sharable device is one that only one

user at a time can access, such as a magnetic tape unit. You MUST, however, separate

the sharable devices from the non-sharable devices by inserting a slash (/) after the

sharable devices, and before any non-sharable devices. For example, either of the

following formats is correct:

DEVTBL SUB0,SUB1,SUB2

DEVTBL /STR0,MTU0

DEVTBL SUB0,SUB1,SUB2,/STR0,MTU0

If your computer has more devices than will fit on one DEVTBL command line, you can

have as many DEVTBL command lines as you want, as long as they are not separated

by other commands.

If you have a single physical disk divided into a large number of logical devices, you

have two options to make your DEVTBL statements shorter. You can specify just the

name of a single device with no unit number, and DEVTBL will read the hidden sector of

the disk to determine the number of logical units to allocate. For example:

DEVTBL DSK

This format works only with SCSI drives.

Or, you can specify a range of logical unit numbers in a DEVTBL statement. For

example:

DEVTBL DSK1-54

Be aware however, that if your system contains multiple disks of the same type, and

they are all defined with the same device name, then you

must

use the dashed method

of defining each drive’s logical units. AMOS will not search for additional drives with

the same name unless they are defined with a DEVTBL statement. For example:

System Operator’s Guide to the System Initialization Command File, Rev. 03