User`s manual

IOT - I/O Configure Disk Controller
3-102
3
Only the $00, $01, $05, and $07 are supported by the I/O
controller drivers.
Attribute Parameters
The parameters and attributes that are associated with a particular
device are determined by a parameter and an attribute mask that is
a part of the device definition. The device that has been selected
may have any combination of the following parameters and
attributes:
Sector Size:
0- 128 1- 256 2- 512
3-1024 4-2048 5-4096 =01 (0-5)?
The number of data bytes per sector.
Block Size:
0- 128 1- 256 2- 512
3-1024 4-2048 5-4096 =01 (0-5)?
The units in which a transfer count is speciÞed when doing a
disk/tape block transfer. The block size can be smaller, equal to,
or greater than the physical sector size, as long as (Block Size) *
(Number of Blocks) / (Physical Sector Size) is an integer.
Sectors/Track =0020?
The number of data sectors per track, and is a function of the
device being accessed and the sector size speciÞed.
Starting Head =10?
The starting head number for the device. It is normally zero for
Winchester and ßoppy drives. It is nonzero for dual volume
SMD drives.
$09 Communications
$0A, $0B Graphic Arts Pre-Press
$0C-$1E Reserved
$0F Unknown or no device type