Installation Guide AHA-2740A Series EISA-to-Fast SCSI Host Adapters The AHA-2740A Series: AHA-2740A AHA-2742A AHA-2740A-Twin AHA-2742A-Twin R AA AAAA AA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAA AA AA AA AHA-2740A Series Installation Guide AA AA AA AA AA AA Part Number: 511053-00, Rev.
1 Getting Started This document provides the basic information needed to quickly install and configure the AHA®-2740A Series of EISA-to-Fast SCSI Host Adapters. The host adapters in the series are differentiated by the presence of an additional SCSI channel (SCSI Channel B) on the two TwinChannel models: AHA-2740A-Twin and AHA-2742A-Twin. Furthermore, the AHA-2742A and AHA-2742A-Twin include an onboard floppy controller and connector.
Location Description J1 External LED Connector J2 Floppy Connector (AHA-2742A and AHA-2742A-Twin only) J3 SCSI Channel A Internal Connector J4 Floppy Enable Jumper (AHA-2742A and AHA-2742A-Twin only) J5 SCSI Channel B Internal Connector (AHA-2740A/2742A-Twin only) J6 SCSI Channel A External Connector U1 Floppy Controller (AHA-2742A and AHA-2742A-Twin only) U2 RAM U5 Host Adapter BIOS U9 AIC-7770 Bus Master SCSI Chip U10 AIC-701 Configuration Chip Default Settings Your host adapter i
The Onboard Floppy Controller (AHA-2742A and AHA-2742A-Twin only) ■ If your floppy diskette drives are already running under another controller, disable the onboard floppy controller by removing the jumper shunt on jumper J4. ■ To use the onboard floppy controller, leave the jumper shunt installed on jumper J4 and then disable your existing floppy controller; refer to your computer or floppy controller documentation.
Note: Only single-ended (non-differential) SCSI devices are supported by the AHA-2740A Series. Consult your SCSI device user documentation. Internal SCSI Cables The internal connectors for SCSI Channel A and SCSI Channel B (AHA-2740A/2742A-Twin only) use a 50-pin SCSI flat ribbon cable with a 50-pin header internal connector. Note: When connecting the 50-pin internal SCSI ribbon cable to both the host adapter and internal SCSI device(s), be sure to maintain pin-1 orientation throughout the bus.
Terminating the Host Adapter The factory installed bus terminators on the host adapter are enabled by default. Host adapter termination should be disabled if you attach SCSI devices to both internal and external connectors, since the host adapter would then be in the middle of the SCSI bus. The following table describes the three possible SCSI device and host adapter (AHA) configurations.
supplied with your computer, host adapter configuration will vary. This section describes the basic steps involved in running the ECU. Running the ECU Place the configuration diskette in your floppy boot drive and reset the computer to boot from this diskette. Run the ECU as instructed by your EISA computer vendor. Copying Files The ECU typically allows you to select among a number of options, including copying new configuration files. Select this option to install the !adp7771.cfg and adp7770.
■ Data FIFO Threshold– Defines the percentage used by the host adapter to manage its internal data FIFO. The default is 100%. ■ Host Adapter BIOS Base Address– Defines the base BIOS address, or disables the host adapter BIOS. The default is D8000h. When choosing the base address, verify that there is no conflict with other devices using the same address. Note: The BIOS must be enabled if you want the computer to boot from a SCSI hard drive attached to the host adapter.
■ SCSI Bus Termination–Enables or disables SCSI termination on the SCSI bus. The default is Enabled. Disable this parameter only if you attach SCSI devices to both internal and external connectors. ■ Primary Channel Selection (AHA-2740A/2742ATwin only)– Allows you to select which SCSI channel (A or B) the host adapter boots from. BIOS Configuration This option allows you to change the configuration of the host adapter BIOS.
■ Support for Bootable CD-ROM– allows you to boot up from a bootable CD-ROM. ■ Support for Int 13h Extensions– provides a mechanism to support disks with more than 1024 cylinders, and to add support for software control of drive locking for removable media. SCSI Device Configuration This option allows you to change certain parameters for each SCSI device connected to the host adapter. Select values for each setting as instructed on the screen's menu.
Utilities The following SCSI utility is available with your host adapter: ■ Format Disk– accesses the Adaptec SCSI LowLevel Format utility. Most SCSI disk drives are preformatted, and do not need reformatting. Select Utilities from the ECU to access Format Disk. 7 Operating System Support DOS/Windows Under MS-DOS 5.0 or higher, up to eight SCSI hard disk drives can be connected to the host adapter without additional software. (Older versions of DOS support up to two hard disk drives.
8 Troubleshooting Computer Will Not Boot From a SCSI Disk Drive If both SCSI and non-SCSI disk drives (e.g., IDE drives) are installed, then the non-SCSI disk drive is always the boot device. If there is no non-SCSI disk drive 1 Make sure your computer's CMOS Setup is set to No Drives Installed, as is required for SCSI host adapters. 2 Try enabling the BIOS Support Option as described in SCSI Device Configuration on page 9. 3 Make sure the SCSI hard disk drive SCSI ID is set to 0.
9 Adaptec Customer Support Services If you have questions about installing or using your Adaptec product, check this document first—you will find answers to most of your questions here. If you need further assistance, please contact us.
FCC Compliance Statement NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference in residential installations. This equipment generates, uses, and can radiate radio frequency energy, and if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.
