Windows NT uses a layered driver architecture. This allows multiple SCSI Host
Bus Adapters (HBA) to be transparently used with multiple tape drives. The
general structure of how a Backup Application communicates with a physical tape
drive is shown below in a very simplified, diagrammatic format.

points to note

The main points to note are:

1. Windows NT tape drivers are effectively "plug-ins" to a generic tape class

driver.

2. Windows NT SCSI HBA drivers are effectively "plug-ins" to a generic SCSI

class driver.

3. Multiple tape drivers and SCSI HBA drivers can be plugged in at the same

time.

4. The class drivers provide the "environment" within which the plug-ins

operate. The class driver does most of the work that is common to the tape
drives and the HBA's (for example, read/write etc), and uses the plug-in to
provide device-specific processing (for example, reading/modifying
particular tape drive-specific settings)

5. This environment (known in programming terms as an "API") can change

slightly from one version of NT to another. (Although the environment is
"usually" backwards compatible, there is no guarantee of this). For this
reason, you should always use the tape drivers made for the version of
Windows NT that you are running.

6. A tape driver is required for each general type of tape drive, for example: a

DAT tape driver, a DLT tape driver, an Ultrium tape driver etc. The driver
will only load and operate if it recognises the SCSI Inquiry string of one or
more tape drives connected to the system.

next question

Go to the next question

"How do I know what drivers I am using at the moment,

and what drivers do I need for running tape backups?"

file:///C|/Documents%20and%20Settings/topher.COL-SPRINGS/Desktop/dltvs80%20manual/document/common/drivers_faqs/eng/nt_q1.htm [11/29/2001 8:35:45 AM]

This manual is related to the following products:

Surestore DLT VS80 Tape Drive