HP 3000 Manuals HP 3000 Manuals
DISCRPS
Enables or disables the rotational position sensing (RPS) feature on a
specified logical device. It requires a special firmware upgrade CS-80
disk drives.
Syntax
DISCRPS ldev {,ENABLE [{,value,value}]}
{,DISABLE }
Parameters
ldev The logical device number of the specified CS-80
disk drive.
ENABLE Enables rotational position sensing on the device.
DISABLE Disables rotational position sensing on the device.
value Allows the time-to-target and window size to be
tuned, in hundreds of micro seconds. If you
specify one value you must specify both values.
The first is interpreted as the time-to-target
value; the second is interpreted as the window size
value. This parameter only works in conjunction
with ENABLE.
(micro seconds)
Default time-to-target 90 (9000 )
window size 30 (3000 )
ONLY use this parameter if you have a clear understanding of its meaning
and implications.
Operation Notes
The DISCRPS command allows you to enable or disable the rotational
position sensing feature for CS-80 disk drives. With RPS enabled, the
disk drive signals its availability to do an I/O only when it is a small
rotational distance away from the target data. This improves system
performance when more than one drive is connected to the same HP-IB
channel.
Use
This command may be issued from a session, job, program, or in BREAK.
Pressing Break has no effect on this command. It may be executed only
from the console unless distributed to users with the ALLOW or ASSOCIATE
commands.
Example
To enable the RPS feature on logical device 1 and display the status of
the disk drive, enter:
DISCRPS 1,ENABLE
SHOWDEV 1
LDEV AVAIL OWNERSHIP VOID DEN ASSOCIATION
1 DISC (RPS) 50 FILES
To use the value parameter with ENABLE to set time-to-target and window
size to the default values, enter:
DISCRPS ldev,ENABLE,90,30
Related Information
Commands SHOWDEV
Manuals CS/80 Instruction Set Programmers Manual (5955-3442)