ASPI (Advanced SCSI Programming Interface) specifies how an application program can communicate with a SCSI (Small Computer System Interface) device through a common SCSI device driver. ASPI provides a set of functions that are common to any SCSI device.
Developed by Adaptec, ASPI has become the industry standard for controlling SCSI devices. The ASPI device driver is the program that actually interacts with the SCSI device. The layering looks something like this: application/utility, ASPI, ASPI driver, SCSI card.