Adaptec 1742A User Manual

Contents

RAMRandom Access Memory. Memory of which any byte can beaccessed directly in a single memory cycle. Information can beread from and written to the memory.Scatter/GatherA device driver feature that allows the host adapter to modify thetransfer data pointer so that a single host adapter transfer cantransfer to many segments of memory in a single transfer, mini-mizing interrupts and overhead.SCBSCSI Control Block. The mechanism used in emulation mode totransfer control information to and from the board. This is equiva-lent to the mailbox in/out system used in standard mode.SCSISmall Computer System Interface.SCSI ASCSCSI Additional Sense Code. Byte 12 of the extended sense infor-mation. Provides a standardized description of the conditiondescribed by the sense information.SCSI DeviceA device attached to a Small Computer System Interface buscable. The device may be an initiator, a target, or capable of bothtypes of operation. The device may be a peripheral device, a hostdevice, or a device mixing both roles.Single-EndedA term referring to the electrical characteristics of the signalsused on the SCSI bus interface. Single-ended signals occupy a sin-gle conductor and are references to a common ground carried onthe cable between the SCSI components attached.Single-Threaded OperationOperation of the computing system such that only one programcan be operating or active at a time. The computing system mustwait until all resources are available before starting an operationand cannot start another operation until the first one is com-pleted. No overlapping of latencies or program operation occurs.EISA-to-Fast SCSI Host Adapter GlossaryGL-7