Chapter 3
How the Drive Operates
Page 14
ST3636A/ST31082A/ST31276A
Universal Translate Mode
Seagate has established a Universal Translate Mode which enables you to
configure the drive in an AT environment to any cylinder, head, and sector
configuration desired. The translate configuration is limited by the maximum
capacity of the drive and host system parameters. Upon initial power-up of the
drive, it will default to the configuration shown below:
Drive:
No. of
Cylinders:
No. of Heads
No. of
Sectors:
ST3636A
1241
16
63
ST31082A
2097
16
63
ST31276A
2482
16
63
After the drive is ready, the host system may issue an Initialize Device
Parameters command (command code 91
hex) to alter the translate
configuration (number of heads and number of sectors per track). The drive will
then calculate the total number of available logical cylinders based upon the
values contained in the Sector Count and Drive/Head registers.
Master/Slave Configuration
When two drives are daisy-chained on the host interface, one must be
designated as the master drive (drive 0) and one as the slave drive (drive 1).
Commands from the host are written in parallel to both drives.
When the D0 jumper on the drive is closed, the drive will assume the role of a
master. When D0 is open, the drive will act as a slave. In single-drive
configurations, D0 must remain in the closed (master) position. For more
information on setting the D0 jumper, refer to chapter 4.
For each command sent from the host, the DRV bit in the Device/Head register
selects the master or the slave drive. When the DRV bit is reset (0), the master
drive is selected, and when the DRV bit is set (1), the slave drive is selected.
Once the drives receive the command, only the drive with jumper D0 set to the
appropriate position will execute the command. For example, if the DRV bit is
set, only the slave drive (jumper D0 open) will execute the command.
☞
☞
Note: If the command is a diagnostic command, both drives will execute the command and the slave
will report its status to the master via the Host PDIAG signal.
Throughout this manual, drive selection always refers to the state of the DRV
bit and the position of the D0 jumper.
Содержание Medalist ST31082A
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Страница 12: ...Table of Contents ST3636A ST1082A ST31276A Page iv ST3636A ST31082A ST31276A...
Страница 24: ...Chapter 2 Specifications Page 12 ST3636A ST31082A ST31276A...
Страница 28: ...Chapter 3 How the Drive Operates Page 16 ST3636A ST31082A ST31276A...
Страница 42: ...Chapter 5 Host Interface Page 30 ST3636A ST31082A ST31276A...
Страница 88: ...Chapter 7 Command Set Page 76 ST3636A ST31082A ST31276A...