User`s manual

.DSKCFIG
5-25
5
Table 5-8. CFGA Fields
Parameter Description
IOSREC Record (Block) size Number of bytes per record (block). Must be an
integer multiple of the physical sector size.
IOSSPT Sectors per track Number of sectors per track.
IOSHDS Number of heads Number of recording surfaces for the speciÞed
device.
IOSTRK Number of cylinders Number of cylinders on the media.
IOSILV Interleave factor This Þeld speciÞes how the sectors are formatted on
a track. Normally, consecutive sectors in a track are
numbered sequentially in increments of 1
(interleave factor of 1). The interleave factor controls
the physical separation of logically sequential
sectors. This physical separation gives the host time
to prepare to read the next logical sector without
requiring the loss of an entire disk revolution.
IOSPSM Physical sector size Actual number of bytes per sector on media.
IOSSOF Spiral offset Used to displace the logical start of a track from the
physical start of a track. The displacement is equal
to the spiral offset times the head number, assuming
that the Þrst head is 0. This displacement is used to
give the controller time for a head switch when
crossing tracks.
IOSSHD Starting head number The Þrst head number for the device.
IOSPCOM Precompensation
cylinder
The cylinder on which precompensation begins.
IOSSR Step The rate at which the read/write heads can be
moved when seeking a track on the disk. The
encoding is as follows:
3-1/2 Inch/
Step Rate Winchester 5-1/4 Inch 8-Inch
Code Hard Disks Floppy Floppy
$00 0 msec 12 msec 6 msec
$01 6 msec 6 msec 3 msec
$02 10 msec 12 msec 6 msec
$03 15 msec 20 msec 10 msec
$04 20 msec 30 msec 15 msec