Adaptec AHA-1740A, 1742A Scatter/Gather, Scsi Device, Single-Ended, Single-Threaded Operation

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EISA-to-Fast SCSI Host Adapter

Glossary

RAM

Random Access Memory. Memory of which any byte can be accessed directly in a single memory cycle. Information can be read from and written to the memory.

Scatter/Gather

A device driver feature that allows the host adapter to modify the transfer data pointer so that a single host adapter transfer can transfer to many segments of memory in a single transfer, mini- mizing interrupts and overhead.

SCB

SCSI Control Block. The mechanism used in emulation mode to transfer control information to and from the board. This is equiva- lent to the mailbox in/out system used in standard mode.

SCSI

Small Computer System Interface.

SCSI ASC

SCSI Additional Sense Code. Byte 12 of the extended sense infor- mation. Provides a standardized description of the condition described by the sense information.

SCSI Device

A device attached to a Small Computer System Interface bus cable. The device may be an initiator, a target, or capable of both types of operation. The device may be a peripheral device, a host device, or a device mixing both roles.

Single-Ended

A term referring to the electrical characteristics of the signals used on the SCSI bus interface. Single-ended signals occupy a sin- gle conductor and are references to a common ground carried on the cable between the SCSI components attached.

Single-Threaded Operation

Operation of the computing system such that only one program can be operating or active at a time. The computing system must wait until all resources are available before starting an operation and cannot start another operation until the first one is com- pleted. No overlapping of latencies or program operation occurs.

GL-7

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Contents User’s Manual Page User’s Manual Copyright Iii Page Table of Contents Adaptec Glossary Index List of Tables List of FiguresPreface Bold ConventionsPage South milpitas blvd. ∙ milpitas, ca 95035 ∙408945-8600 General Product Information OverviewAdaptec EISA-to-Fast Scsi Host Adapter Overview AHA 1740A/1742A/1744 Program Files Installation SoftwareAHA 1740A/1742A/1744 Operation Modes Bios Operation ModesSystem Caching Description AHA-1740A/1742A/1744 Product Specifications Product Specifications∙ Installation Guide Associated Documentation∙ Technical Reference Manual Unpacking and Inspection Hardware InstallationPreparation Scsi Device Termination Scsi TerminatorsScsi ID Scsi ParityPhysical Installation in the System Adaptec Standard Mode Enhanced ModeMultiple Host Adapter Support Standard and Enhanced Modes Running the ADL Program Adaptec Download UtilityHost Adapter Listing ADL Main Menu Download Firmware Screen Download FirmwareDownload Warning Message Screen Firmware Information Enhanced Mode Firmware InformationLow-Level Format Device Selection Screen Low-Level FormatLow-Level Format Option Selection Screen Low-Level Format Options screen displaysExiting the ADL Program Exiting the ADL ProgramPage Standard Mode Operation Host Adapter Bios OperationAdaptec Enhanced Bios Boot Message Enhanced Mode OperationBoot Message With Error Detection Enabled Determining Problems Using the LED TroubleshootingAHA 1740A/1742A/1744 LED Flash Codes Problems Detected During InstallationEISA-to-Fast Scsi Host Adapter Troubleshooting Problems Using a Scsi and a Standard Disk Drive Problems Booting the System from a Scsi DriveProblems Using Two Scsi Drives Adaptec Extended Translation Using DOS Disk Drives Over 1 GigabyteDOS 1 Gigabyte Limit When to Use Extended Translation With DOS Version 5 Only Using Extended TranslationDrives With Mixed Partitions Using Fdisk Questions and Answers About Extended TranslationLoad ASW-1410 v3.0a Adaptec DOS/Windows Loading the I/O Operating Environment SoftwareNovell NetWare OS/2Unix Glossary Asynchronous Event Notification Bus Device ResetCommand Control Block Command Descriptor BlockControl Microprocessor Common Command SetConfiguration Direct Memory AccessEnhanced Mode FirmwareHost Initiator Host AdapterIBM PC-AT Compatible Industry Standard ArchitectureMulti-tasking Operation MailboxMailbox Out ManagerSingle-Threaded Operation Scatter/GatherScsi Device Single-EndedTagged Queuing Standard ModeSynchronous Data Transfer Synchronous Data Transfer NegotiationIndex AHA-1740A/1742A/1744 Index-2 Index-3 AHA-1740A/1742A/1744 Index-4