Adaptec 1742A, AHA-1740A, 1744 user manual Scsi Terminators, Scsi Device Termination

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EISA-to-Fast SCSI Host Adapter	Hardware Installation

SCSI Terminators

The SCSI bus must be terminated correctly to ensure proper op- eration. Only the first and last device on the SCSI bus (cable) should have the terminating resistors installed. All other SCSI devices should have the terminating resistors removed. The fol- lowing figure shows two examples of SCSI device connections to the AHA-1740A/1742A/1744 Host Adapter.

Figure 2-1. SCSI Device Termination

The AHA-1740A/1742A/1744 is a SCSI device, and has socketed on-board terminators that should be removed if both the internal and external host adapter connectors are used. These can be rein- stalled at a later time, if desired. On the AHA-1740A/1742A re- move the RN5, RN6 and RN7 terminators. On the AHA-1744 remove the RN2, RN4 and RN5 terminators.

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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 SpecificationsAssociated Documentation ∙ Installation Guide∙ Technical Reference Manual Unpacking and Inspection Hardware InstallationPreparation Scsi Device Termination Scsi TerminatorsScsi ID Scsi ParityPhysical Installation in the System Adaptec Enhanced Mode Standard 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 Disk Drives Over 1 Gigabyte Extended Translation Using DOSDOS 1 Gigabyte Limit Using Extended Translation When to Use Extended Translation With DOS Version 5 OnlyDrives With Mixed Partitions Questions and Answers About Extended Translation Using FdiskLoad ASW-1410 v3.0a Adaptec DOS/Windows Loading the I/O Operating Environment SoftwareOS/2 Novell NetWareUnix Glossary Command Control Block Bus Device ResetCommand Descriptor Block Asynchronous Event NotificationConfiguration Common Command SetDirect Memory Access Control MicroprocessorFirmware Enhanced ModeHost IBM PC-AT Compatible Host AdapterIndustry Standard Architecture InitiatorMailbox Out MailboxManager Multi-tasking OperationScsi Device Scatter/GatherSingle-Ended Single-Threaded OperationSynchronous Data Transfer Standard ModeSynchronous Data Transfer Negotiation Tagged QueuingIndex AHA-1740A/1742A/1744 Index-2 Index-3 AHA-1740A/1742A/1744 Index-4