DISCRPS
DISCRPS
Enables or disables the rotational position sensing (RPS)
feature on a specified logical device. It requires special
firmware upgrade CS-80 disk drives. (CM)
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 works only in conjunction with
ENABLE.
(micro seconds)
---------------
Default time-to target 90 (9000 )
window size 30 (3000 )
CAUTION
Do not vary from the default values for time-to-target and window size
unless you have a clear understanding of their meaning and the
consequences of using different values.
OPERATION
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.
This command may be issued from a session, job, in BREAK, or
from a program. Pressing [Break] has no effect on this
command. It may be executed only from the console unless
it has been distributed to users with the ALLOW or ASSOCIATE
command.
EXAMPLE(S)
To enable the RPS feature on logical device 1 and display
the drive's status, 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, enter
DISCRPS ldev,ENABLE,90,30
ADDITIONAL INFORMATION
Commands: SHOWDEV
Manuals : CS/80 Instruction Set Programmers Manual(5955-3442)