SCSI Pass Through Direct application (SPTD) is an Application Programming Interface (API) and a device driver created by Duplex Secure Ltd. This application offers a way of accessing SCSI storage devices. SCSI, or Small Computer System Interface, is a group of standards used in physically linking and transferring data between peripheral devices and computers. Since the SCSI Pass Through Direct (SPTD) application is a proprietary application, it is not available to the public. This program is mainly used by Alcohol 120% and Daemon Tools. The PowerArchiver Pro 2010 also uses this program but has an option to disable it.
The SCSI Pass Through Direct program works like other SCSI Pass Through Interfaces, such as Microsoft standard SPTI and Adaptec’s ASPI. The only difference is that the SPTD application gives users the ability to control the devices without compromising them with malicious third party rootkit applications or filter drivers.
Most products or applications that use the SCSI Pass Through Direct program will not work unless the SPTD application is installed. When using products bundled with SPTD program, the SPTD application will not automatically uninstall together with the product. A separate uninstallation process is required in order to remove the SPTD program from the computer system.