User Guide

Ampex 1308911-02 2-1
Software Overview Introduction
Section 2
Software Overview
2.1 Introduction
This section provides a general overview of the host system tape device driver interface, tape
drive behavior, the libdd2 API functions, and the DD-2 Tape Management Utilities. Table 2-1.
lists the operations performed by the libdd2 functions and the Tape Management Utilities.
With the Ampex or IRIX tpsc tape device driver installed, the standard UNIX open, close,
read, write, read_v, and write_v system calls access the DST drive.
Ampex provides the libdd2 programming interface described in this manual and recommends
this interface for all new application development.
The following programming interfaces are available but are not documented in this manual:
• mtio/sto – For compatibility with existing UNIX tape handling programs, the Ampex and
IRIX tpsc drivers provide an mtio/stio interface conforming to mtio/sto conventions for
UNIX host platforms.
• ioctl () – The Ampex and IRIX tpsc drivers support this standard UNIX function for
device control.
• DSTIOCPASSTHRU – This ioctl code interface provides full SCSI protocol-specific
access to the Ampex tape drives.
2.2 Tape Device Driver
Ampex DST and DIS tape drives are compatible with the Ampex DST/DIS tape device driver
and the IRIX tpsc tape device driver. Both drivers are implemented as standard UNIX raw
character I/O devices with fixed block interfaces. They support multiple Ampex tape drives on
a single UNIX host but not multiple users per tape drive; only one process can have the tape
device driver open at any one time. Table 2-2 lists the interfaces through which a DST or DIS
tape drive can be operated by an application program or from the UNIX command line.
The Ampex DST/DIS tape device driver is used on the following platforms:
• Digital Equipment Corporation Digital UNIX (formerly DEC OS/F 1)
• Hewlett Packard HP-UX
• IBM AIX
• Sun Microsystems Solaris