SCSI Miniport Driver Entries

The basic SCSI miniport driver entries in the Registry are found under subkeys in the following path:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services

Each subkey's name is the same as the driver's filename minus the .SYS filename extension; for example, FD8XX, which is the entry for all Future Domain 800-series SCSI adapter. The Registry includes entries for at least the following SCSI miniport device drivers:

The contents of a SCSI miniport subkey are standard for all SCSI miniport drivers, with these basic value entries:

For each SCSI miniport subkey, there can be one or more other subkeys named Parameters\Device or Parameters\DeviceN, where N = 0, 1, 2, and so on. The value of N corresponds to the SCSI host adapter number. If the subkey name is Device, the value is globally defined. If the subkey name is DeviceN, the value only pertains to the particular SCSI host adapter.

The SCSI miniport driver recognizes several optional value entries that can be defined under these subkeys, as described in this section.

InitiatorTargetId REG_DWORD Number

Sets the SCSI bus host adapter ID. It is used by host adapters that can set the initiator ID from software.

Default: Uninitialized

MaximumLogicalUnit REG_DWORD Number

Controls the number of logical units per target controller that are scanned for by the SCSI miniport driver. Most devices only support one logical unit, and some devices may fail if more than one logical unit is scanned for.

Default: 8

ScsiDebug REG_DWORD Number

This value is used to set the value of the ScsiDebug variable, which controls the verbosity of DebugPrint, with 0 being the least verbose. This is used for debugging.

Default: 0

The following value entries are used to fix problems such as device time-outs or controller detection errors but will reduce I/O performance. These value entries can be abbreviated. For example, a value entry of Disable will cause DisableSynchronousTransfers, DisableTaggedQueuing, DisableDisconnects, and DisableMultipleRequests to be set.

Note The system must be restarted before these options take effect.

BreakPointOnEntry REG_DWORD 0 or 1

A DbgBreakPoint() call is immediately made inside of SpParseDevice. This is used for debugging.

Default: 0 (disabled)

DisableDisconnects REG_DWORD 0 or 1

Disables disconnects on the SCSI bus. It causes all requests to be executed sequentially.

Default: 1 (enabled)

DisableMultipleRequests REG_DWORD 0 or 1

Prevents the SCSI miniport driver from sending more than one request at a time per SCSI device.

Default: 1 (enabled)

DisableSynchronousTransfers REG_DWORD 0 or 1

Disables synchronous data transfers on the SCSI bus.

Default: 1 (enabled)

DisableTaggedQueuing REG_DWORD 0 or 1

Disables SCSI-II tagged command queuing on the host adapter.

Default: 1 (enabled)

DriverParameter Data type is specific to driver A string

A pointer to this data is passed to the SCSI miniport driver in a miniportFindAdapter routine. It is the fourth parameter, ArgumentString. A miniport driver uses this data to define the IRQ number for the SCSI host adapter, but other applications for the data are possible.

The data type for this value is defined by the specific SCSI miniport driver developer. If the data type is REG_SZ, the Unicode string is converted to an ANSI string before transferring it to the SCSI miniport driver.

The following drivers currently use the DriverParameter value entry: