Adaptec 1742A Glossary, Adapter Command, AHA-1540B, AHA-1542B, AHA-1740A/42A/44, Aspi

Glossary

Adapter Command

A command transmitted to the host adapter using the Command Data Out Port and the Data In Port. The commands are sequenced using the Control Port, the Status Port, and the Inter- rupt Flag Port. Abbreviated as IOCP command.

AEN

See Asynchronous Event Notification

AHA-1540

Adaptec host adapter for connecting SCSI devices to the PC-AT®backplane bus. The AHA-1740A/42A/44 is an enhanced version of the AHA-1540.

AHA-1540B

The enhanced high-performance Adaptec host adapter for connect- ing SCSI devices to the PC-AT backplane bus.

AHA-1542B

The enhanced high-performance Adaptec host adapter for connect- ing SCSI devices and standard IBM-compatible floppy disk devices to the PC-AT backplane bus.

AHA-1740A/42A/44

Either the AHA-1740A, 1742A or the AHA-1744.

ASPI

Advanced SCSI Programming Interface. A software architecture which permits device modules to migrate across different hard- ware by communicating with the hardware through a pass- through interface to a manager written to the specific hardware.

Asynchronous Data Transfer

Data transfer performed by the SCSI interface involving the inter- locking of a signal to the initiator (REQ) and a signal to the target (ACK) such that each step of the data transfer protocol must occur before the next step can begin. Characterized by a low data

GL-1