Adaptec 1742A User Manual

Contents

Common Command SetA de facto standard SCSI command set for communication withfixed disk drives. The Common Command Set (CCS) is the basisfor the SCSI-2 command set for all types of peripheral devices.ConfigurationThe operation of configuring a device on the EISA bus throughaccess of registers in the device by the host. It replaces themethod of using jumpers common on ISA bus devices.Control MicroprocessorAn integrated circuit computer used to execute the software thatcontrols the host adapter’s operation.Device DriverA program that is linked with, or attached to, an operating sys-tem to map the software interface of the operating system to therequirements of attached peripheral devices and host adapters.Under ASPI, the main component associated with the board isknown as a Manager.DMASee Direct Memory AccessDifferentialA term referring to the electrical characteristics of the signalsused on the SCSI bus interface. Differential signals occupy twoconductors with a positive (+) and negative (-) polarity componentof the signal. This minimizes the effect of common mode signalnoise and allows the SCSI bus to operate reliably over greater dis-tances at a higher speed.Direct Memory AccessA mechanism that allows hardware control of the transfer ofstreams of data to or from the main memory of a computing sys-tem. The mechanism may require setup by the host software.After initialization, it automatically sequences the required datatransfer and provides the necessary address information.Disconnect/ReconnectDisconnect is the function that occurs when a target releases con-trol of the SCSI bus, allowing the bus to go to the Bus Free phase.EISA-to-Fast SCSI Host Adapter GlossaryGL-3