Adaptec 1742A User Manual

Contents

Host AdapterA hardware printed circuit board that installs in a standardmicrocomputer backplane and provides a SCSI bus connection sothat SCSI devices can be connected to the microcomputer. A hostadapter is intelligent if it has a simple high-level software inter-face to the microcomputer. A host adapter is dumb if the micro-computer must directly manage the SCSI protocol using themicrocomputer processor.IBM PC-AT CompatibleAny computer system that emulates exactly the IBM PC-AT andthat uses an ISA backplane bus.Industry Standard ArchitectureThe IBM PC-AT functions have been duplicated by a number ofmanufacturers. All the IBM PC-AT compatible machines use abackplane bus that very closely emulates the function of the back-plane bus of the PC-AT. Because of the broad usage of this busstructure, it has become known as the Industry Standard Archi-tecture bus, even though there is no presently accepted standardfor the bus.InitiatorA SCSI device that requests an operation to be performed byanother SCSI device (the target). The initiator provides all thecommand information and parameters required to perform theoperation, but the details of the operation are actually sequencedby the target.ISASee Industry Standard ArchitectureLogical UnitA physical or virtual device addressed through a target.Logical Unit NumberAn encoded three-bit identifier for a logical unit.LUSee Logical UnitLUNSee Logical Unit NumberEISA-to-Fast SCSI Host Adapter GlossaryGL-5