SCSI Pass-Through Programmer's Guide

Document Summary
The aim of this document is two fold:
1) To educate an application programmer on how to use ioctl() calls on SCSI pass
through (SPT) device files to send SCSI commands directly to SCSI devices
2) Discuss the various recent enhancements in MPE/iX to make the SPT interface better
and convenient to use
We begin with a discussion of SPT (what is it?, why use it?) followed by a program setup for
using SPT to directly communicate with SCSI devices. We then discuss SYSGEN device
configuration for making SPT calls on SCSI devices.
A description of the recent enhancements to SPT on MPE/iX follows next. The
enhancements are:
• Facility in SCSI DMs to provide user notification of Bus Resets
• A user callable routine to convert a device's LDEV number to it's physical path.
• DUP capability on SPT device files to allow fork() calls in application programs
• Ability to use SPT device files across boots
A bug in the porting of the /sys/libIO.H header file has also been fixed.
Appendix-A includes a C program listing which shows how a SCSI Inquiry command can be
executed on a SPT device file. The appendix also provides a snapshot of the results of
executing the SCSI inquiry command on different types of devices.
Appendix-B has a listing of sample programs calling the new HPLDEVTOIOPATH user
callable routine and also has a snapshot of the output.
Appendix-C has a list of JAG numbers for each of the above enhancements and the patch IDs
in which they are available.
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