SCSI Pass-Through Direct

Not to be confused with SCSI Pass Through Interface.

SCSI Pass Through Direct (SPTD)

Stable release	1.90 / January 19, 2018 (2018-01-19)
Operating system	Windows 2000; Windows XP; Windows Vista; Windows 7; Windows 8; Windows 10
Platform	IA-32 and x64
Size	1 MB
Type	Device driver; Application programming interface
License	Proprietary Device driver: Freeware API: Commercial software
Website	www.duplexsecure.com/en/home

SCSI Pass Through Direct (SPTD) is a proprietary device driver and application programming interface (API) that provides a method of access to SCSI storage devices. Originally developed in 2004 by Duplex Secure Ltd., it is now owned and maintained by Disc Soft Ltd., the developer of Daemon Tools.

Uses

SPTD is used by Daemon Tools and Alcohol 120%. It is also utilized in PowerArchiver Pro 2010 (v11.60+); however, a configurable option is available to disable it. It is known to be incompatible with kernel-mode debugging including WinDbg and Microsoft's other command line debuggers as well as SoftICE. Further, certain versions of the freeware optical media burning software ImgBurn will issue a warning, "SPTD can have a detrimental effect on drive performance", if the application detects that SPTD is active or installed.

ConeXware, Inc. (the maker of PowerArchiver) claims that in their internal testing, SPTD improved optical drive performance by up to 20 percent in comparison to the "old school" SCSI Pass Through Interface.

See also

• SCSI
• Advanced SCSI Programming Interface (ASPI)
• SCSI Pass Through Interface (SPTI)

Further reading

1. "SCSI Port I/O Control Codes". Microsoft Developer Network. Microsoft Corporation. 3 May 2011. Archived from the original on 22 October 2012. Retrieved 30 May 2011.
2. "SCSI Pass Through Interface". Microsoft Developer Network. Microsoft Corporation. 3 May 2011. Archived from the original on 22 October 2012. Retrieved 30 May 2011.