User Guide

Ampex 1308911-02 iii
DST/DIS Tape Drive UNIX Programmer’s Guide Addendum
Addendum
Introduction
This addendum provides supplementary information applicable to using the libdd2 API
version 6.0 with SGI Irix 6.5 tpsc magnetic tape (mt) and devscsi passthru (pt) devices, or Irix
6.4 TDR tpsc devices. The information covers only those features that are unique to the IRIX
TDR5 configuration. See the remainder of the document for information on other features that
are common to all supported UNIX platforms.
API Functions
In the IRIX TDR5 environment, the libdd2 API uses the SGI tpsc or devscsi driver rather than
the Ampex DST tape device driver. Those functions that could not be implemented through
the mt interface to the tpsc driver were replaced by SCSI passthru versions that use the pt
interface to the devscsi driver.
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The following functions, identified by the suffix _pt, use the passthru interface to the
devscsi driver. They behave the same as the standard functions that are available on other
platforms. See the manual pages in Section 5 for details.
P
assthru Functions Standard Functions
dst_clrlog_pt() dst_clrlog()
dst_format_pt() dst_format()
dst_getdrive_pt() dst_getdrive()
dst_getdrive_ex_pt() dst_getdrive_ex()
dst_getlog_pt() dst_getlog()
dst_gettrace_pt() dst_gettrace()
dst_setdrive_pt() dst_setdrive()
dst_setpart_pt() dst_setpos()
dst_status_pt() dst_status()
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The following functions use the mt interface to the tpsc device driver but behave
differently than on other supported platforms. When referring to the manual pages in
Section 5, note the following:
– dst_getparam() reports only those attributes that are available under IRIX TDR5
(see “Device Special Files” on page iv).
– dst_setparam() is not capable of setting the device driver debug level. In addition
it can set the data block size only when the drive is positioned to BOT or
immediately after a filemark.