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Adaptec 1744, AHA-1740A, 1742A user manual System Caching Description, adaptec

Models: AHA-1740A 1742A 1744

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System Caching Description

adaptec	AHA-1740A/1742A/1744

System Caching Description

The AHA-1740A/1742A/1744 fully supports operating systems caching to maximize overall system performance. Having RAM on the host adapter can actually decrease overall system perform- ance while adding cost. Operating systems such as Novell® Net- Ware, OS/2®, UNIX, XENIX, DOS and Windows™ have built-in cache and caching the same data in the operating system and on the host adapter can bog down system performance.

Overall system performance is increased by increasing the size of the operating system cache (i.e. add more RAM to the system motherboard), and by utilizing the advanced multithreading fea- tures of SCSI to minimize the mechanical limitations of SCSI peripherals (such as disk seek times by using zero latency reads).

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Adaptec 1744, AHA-1740A, 1742A user manual System Caching Description, adaptec

Contents

AHA-1740A/1742A/1744 EISA-to-Fast SCSI Host Adapter User’s ManualPage AHA-1740A/1742A/1744 EISA-to-Fast SCSI Host Adapter User’s ManualCopyright TrademarksChanges LiteratureTechnical Support Page Table of Contents Chapter Two Hardware InstallationChapter Three Using the Configuration Utility Chapter One OverviewChapter Six Host Adapter BIOS Operation adaptecChapter Four Multiple Host Adapter Support Chapter Five Adaptec Download UtilityChapter Seven Troubleshooting Table of Contents EISA-to-Fast SCSI Host AdapterAppendix A Disk Drives Over 1 Gigabyte Appendix B Loading the I/O Operating Environment Softwareadaptec List of FiguresList of Tables Preface Helvetica Italics Conventionsbold Page Printed in Singapore 691 south milpitas blvd. ∙ milpitas, ca 95035 ∙408945-8600STOCK NO Rev BGeneral Product Information OverviewChapter One The AHA-1740A/1742A/1744 supports asynchronous, synchro- nous, and Fast SCSI data transfers on the SCSI bus. Asynchro- nous data transfers support up to 2 MBytes/sec, synchronous transfers support up to 5 MBytes/sec, and Fast synchronous trans- fers support up to 10 MBytes/sec. Devices using different trans- fer rates can all be used on the same SCSI cable. The AHA-1740A/1742A/1744 is both SCSI-1 and SCSI-2 compatible, and supports both SCSI-1 and SCSI-2 devices adaptecEISA-to-Fast SCSI Host Adapter Overviewadaptec Installation SoftwareTable 1-1. AHA 1740A/1742A/1744 Program Files BIOS Operation Modes Table 1-2. AHA 1740A/1742A/1744 Operation ModesSystem Caching Description adaptecProduct Specifications Table 1-3. AHA-1740A/1742A/1744 Product SpecificationsPhysical Dimensions Power Requirements∙ Installation Guide Associated Documentation∙ Technical Reference Manual adaptecUnpacking and Inspection Hardware InstallationChapter Two Preparation adaptecSCSI Terminators Figure 2-1. SCSI Device Terminationadaptec SCSI ParitySCSI ID Physical Installation in the System 7. Carefully reinstall the cover of the computer adaptecMultiple Host Adapter Support Chapter FourStandard Mode Enhanced ModeStandard and Enhanced Modes adaptecAdaptec Download Utility Chapter FiveRunning the ADL Program ∙ ∙ ∙ ∙Figure 5-1. Host Adapter Listing adaptec∙ ∙ ∙ Figure 5-2. ADL Main Menuadaptec Download FirmwareFigure 5-3. Download Firmware Screen Figure 5-4. Download Warning Message Screen adaptec Firmware InformationFigure 5-5. Enhanced Mode Firmware Information Low-Level Format Figure 5-6. Low-Level Format Device Selection ScreenEISA-to-Fast SCSI Host Adapter Adaptec Download Utilityadaptec The Low-Level Format Options screen displaysFigure 5-7. Low-Level Format Option Selection Screen Exiting the ADL Program Figure 5-8. Exiting the ADL ProgramEISA-to-Fast SCSI Host Adapter Adaptec Download UtilityPage Host Adapter BIOS Operation Figure 6-1. Standard BIOS Boot MessageChapter Six Standard Mode OperationThe BIOS version and operation mode of the AHA- 1740A/1742A/1744 appear at the top of the message, followed by a list of the identified SCSI devices adaptecFigure 6-2. Enhanced BIOS Boot Message Enhanced Mode OperationP40S 940-40-94XX - Drive C 80h Figure 6-3. Boot Message With Error Detection Enabledadaptec Chapter Seven TroubleshootingDetermining Problems Using the LED adaptec Problems Detected During InstallationTable 7-1. AHA 1740A/1742A/1744 LED Flash Codes If the following message displays adaptec Problems Booting the System from a SCSI DriveProblems Using a SCSI and a Standard Disk Drive EISA-to-Fast SCSI Host Adapter Problems Using Two SCSI DrivesTroubleshooting adaptec AHA-1740A/1742A/1744Extended Translation Using DOS Disk Drives Over 1 GigabyteAppendix A The DOS 1 Gigabyte LimitWhen to Use Extended Translation With DOS Version 5 Only Using Extended TranslationDrives With Mixed Partitions adaptecLoad ASW-1410 v3.0a Using FdiskQuestions and Answers About Extended Translation adaptec DOS/Windows Loading the I/O Operating Environment SoftwareAppendix B Novell NetWare OS/2Unix adaptecAdapter Command GlossaryAHA-1540 AHA-1540BBus Device Reset Command Control BlockCommand Descriptor Block Asynchronous Event NotificationCommon Command Set ConfigurationDirect Memory Access Control MicroprocessorEEPROM EISAEnhanced Mode EPROMHost Adapter IBM PC-AT CompatibleIndustry Standard Architecture InitiatorMailbox In Mailbox OutManager Multi-tasking OperationScatter/Gather SCSISCSI ASC SCSI DeviceStandard Mode Synchronous Data TransferSynchronous Data Transfer Negotiation Tagged QueuingIndex AHA-1740A/1742A/1744 Index-2adaptec EISA-to-Fast SCSI Host Adapter IndexIndex-3 AHA-1740A/1742A/1744 adaptec RIndex-4