Maxtor VL 17 manual Subsystem Configuration, Jumper Location/Configuration, Cylinder Limitation

PRODUCTDESCRIPTION

Subsystem Configuration

Dual Drive Support

Two drives may be accessed via a common interface cable, using the same range of I/O addresses. The drives are jumpered as device 0 or 1 (Master/Slave), and are selected by the drive select bit in the

Device/Head register of the task file.

All Task File registers are written in parallel to both drives. The interface processor on each drive decides whether a command written to it should be executed; this depends on the type of command and which drive is selected. Only the drive selected executes the command and activates the data bus in response to host I/O reads; the drive not selected remains inactive.

A master/slave relationship exists between the two drives: device 0 is the master and device 1 the slave. When J50 is closed (factory default, figure 2-1), the drive assumes the role of master; when open, the drive acts as a slave. In single drive configurations, J50 must be closed.

Cable Select Option

CSEL (cable select) is an optional feature per ANSI ATA specification. Drives configured in a multiple drive system are identified by CSEL’s value:

–If CSEL is grounded, then the drive address is 0.

–If CSEL is open, then the drive address is 1.

Jumper Location/Configuration

Darkened jumper pins indicate factory-installed (default) shunts.

JUMPER CONFIGURATION	J50	J48	J46	J44	J42
Master/Slave
Only drive in single drive system*	C
Master drive in dual drive system*	C
Slave drive in dual drive system	O
Cable Select
Disabled*		O
Enabled		C
4092 Cylinder Limitation
Disabled*			O
Enabled			C
Factory Reserved				O
Factory Reserved					O
Key * = Default C = Closed (jumper installed) O = Open (no jumper installed)

Figure 2-1

PCBA Jumper Location and Configuration

4092 Cylinder Limitation

On some older BIOS', primarily those that auto-configure the disk drive, a hang may occur when the drive cylinder value exceeds 4096. The 4092 Cylinder Limitation jumper reduces the capacity in the Identify Drive to 4092 allowing large capacity drives to work with older BIOS'. A software driver is required to access the full capacity of the drive.

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