Advanced SCSI Programming Interface

ASPI ( Advanced SCSI Programming Interface , mutatis mutandis Advanced SCSI Programming Interface ) is a programming interface for the uniform control of CD-ROM - or DVD - drives , especially burners under the operating systems MS-DOS , Windows , OS / 2 and Netware . Contrary to what the name suggests, ASPI is not only used for actual SCSI devices, but also for devices with ATAPI , USB and FireWire connections, since these also use the SCSI communication protocol.

functionality

An ASPI manager said software provides an interface between the so-called ASPI modules (device drivers and applications with direct SCSI support), a SCSI host adapter (ugs. SCSI controller), and thereto attached SCSI devices. This software is written specifically for a host adapter and an operating system; Its main purpose is to abstract the peculiarities of the host adapter and to provide a uniform access method.

Under DOS, this interface is finally used by an ASPI-compatible drive driver, which provides the drive content to the operating system.

Under Windows 9x and Windows NT, however , the ASPI manager is universal and relies on the device drivers already provided by the operating system. Therefore, the capabilities of the ASPI manager concentrate less on a possibly already established SCSI connection, but on sending standardized SCSI commands to e.g. B. also ATAPI devices (SCSI pass-through functionality), as they mainly require burning programs, and the detection of devices capable of doing so.

history

ASPI was developed around 1990 by Adaptec , then a leading manufacturer of SCSI host adapters . The model was the driver model for SCSI devices on Ampro computers invented by Douglas Goodall in 1983 , which was adopted by an in-depth Ampro employee when he switched to Adaptec. Initially the operating systems DOS, Windows 3.x, OS / 2 and Netware were supported. Originally only SCSI devices could be addressed; With the increasing spread of CD burners in the mid-1990s, support for ATAPI devices followed, since the interface used up to now did not allow write access to CDs. The manufacturers of SCSI host adapters (for example BusLogic, DPT, AMI, Future Domain, DTC) delivered their own ASPI managers together with their hardware, which established a software standard.

Adaptec also supplied universal DOS drivers for SCSI hard drives (ASPIDISK.SYS) and CD-ROM drives (ASPICD.SYS). For read access to CD / DVD-ROM drives under Windows 3.x, a drive installed under DOS is sufficient; the Windows 3.x driver (WNASPI.DLL) is only required for Windows burning programs.

Microsoft licensed the ASPI drivers from Adaptec and shipped them with its Windows 9x operating systems. Meanwhile, Microsoft developed SPTI (SCSI Pass-Through Interface), an in-house replacement for ASPI for use with Windows NT . Therefore, in 2000 , XP and Windows Server 2003, a built-in ASPI driver was dispensed with in favor of SPTI. However, since the standard was already widespread, manufacturers of hardware and burner software continued to deliver ASPI managers in order to maintain existing compatibility. SPTI, however, cannot be installed on other systems.

To support USB drives under DOS, Panasonic developed a universally applicable ASPI driver (USBASPI.SYS), which at the same time bypasses the lack of native USB support by DOS.

At Adaptec, development of the official ASPI driver ended in November 2003 with version number 4.71.2.

driver

ASPI is primarily provided by the following drivers.

operating system	Driver file (s)	Supplied
DOS	ASPI4DOS.SYS or USBASPI.SYS (for USB drives)	No
Windows 3.1x	WINASPI.DLL	No
Windows 95, 98 and ME	WNASPI32.DLL, WINASPI.DLL, APIX.VXD, ASPIENUM.VXD	Yes
Windows NT, 2000, XP and 2003	WNASPI32.DLL, ASPI32.SYS	No

Web links

documentation

Adaptec: ASPI for Win32 Technical Reference , November 6, 2001.

driver

Adaptec ASPI driver for DOS (16 bit) , as of February 25, 2000.

Adaptec ASPI driver for Windows (32 bit) , as of November 23, 2003, last published version 4.71.2.

ForceASPI ( Memento from June 6, 2003 in the Internet Archive ), installation help for ASPI drivers under Windows.

Individual evidence

↑ Douglas W. Goodall - Ampro Computers : "I worked briefly at Ampro in order to modify the. CP / M-80 BIOS for the Little Board Z80 to support SCSI hard disk operations. […] I suggested my skills would be better used working with a 16-bit card such as an 80186 . [...] I wrote the SCSI support for that board as well. [...] I taught a staff employee the principles of my driver architecture. He then left Ampro and went to work for Adaptec , where he reproduced my driver architecture and it ended up being called ASPI. "
↑ Ben Myers: More on ASPI .

[1] Douglas W. Goodall - Ampro Computers : "I worked briefly at Ampro in order to modify the. CP / M-80 BIOS for the Little Board Z80 to support SCSI hard disk operations. […] I suggested my skills would be better used working with a 16-bit card such as an 80186 . [...] I wrote the SCSI support for that board as well. [...] I taught a staff employee the principles of my driver architecture. He then left Ampro and went to work for Adaptec , where he reproduced my driver architecture and it ended up being called ASPI. "

[2] Ben Myers: More on ASPI .