Adaptec AHA-2740-T Installation guide

3. Make sure the SCSI hard disk drive SCSI ID is
set to ID 0. The drive SCSI ID is normally set
with jumpers or switches on the drive. Each
SCSI devices should be set to a unique SCSI ID.
4. Make sure the SCSI termination is set correctly.
(See Section 5 , Connecting Peripherals for
information on SCSI termination.)
5. A low-level format of the SCSI hard disk may be
necessary. Be sure to backup first, then run the
Format utility accessible through the EISA
Configuration utility.
Multiple Host Adapters
Make sure that each host adapter is set to a separate BIOS address. Or, disable the BIOS on all but
one of the host adapters.
Adaptec Customer Support
The Adaptec electronic Bulletin Board Service
(BBS) provides information on software
upgrades, new releases, technical advice, and
more. The BBS can be reached 24 hours a day at
408-945-7727; 1200/2400/9600 baud, 8 data bits,
1 stop bit, no parity.
The Adaptec Technical Support Hot Line
can be reached at 800-959-SCSI (7274), or
408-945-2550; M-Th: 6:00 a.m. to 5:00 p.m.,
F: 6:00 a.m. to 3:00 p.m. PST.
The Adaptec Technical Support FAX can be
reached 24 hours a day at 408-945-6776.
10 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. However, there is no guarantee that
interference will not occur in a particular installation.
If this equipment does cause interference to radio or television
equipment reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct
the interference by one or more of the following measures:
Reorient or relocate the receiving antenna
Move the equipment away from the receiver
Plug the equipment into an outlet on a circuit different
from that to which the receiver is powered
If necessary, the user should consult the dealer or an
experienced radio/television technician for additional
EISA-to-Fast SCSI Host Adapters
Installation Guide
CAUTION: Only equipment certified to comply with Class B
(computer input/output devices, terminals, printers, etc.)
should be attached to this equipment, and must have shielded
interface cables.
Finally, any change or modifications to the equipment by the
user not expressly approved by the grantee or manufacturer
could void the user’s authority to operate such equipment.
This device complies with part 15 of the FCC rules. Operation
is subject to the following two conditions: (1) this device may
not cause harmful interference and (2) this device must accept
any interference received, including interference that may
cause undesired operation.
Adaptec software can be ordered by calling
800-442-7274; M-F: 5:00 a.m. to 6:00 p.m. PST.
Additional documentation for Adaptec products
can be requested by calling 800-934-2766;
M-F: 5:00 a.m. to 6:00 p.m. PST.
Adaptec, Inc.
691 South Milpitas Boulevard
Milpitas, CA 95035
Copyright  1993, Adaptec, Inc.
All rights reserved. Adaptec and the Adaptec logo are
registered trademarks, and AHA and TwinChannel are
trademarks of Adaptec, Inc.
Printed in Singapore
Stock No.: 510364-00 Rev. A RQ 1/93
Information subject to change without notice.
▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲
Table 1. Host Adapter Components
Getting Started
This guide provides the basic steps required for
installation of the AHA®-2740/2742 and the
AHA-2740-T/2742-T EISA-to-Fast SCSI Host
Adapters. Procedures for all adapters are the same
except when regarding the on-board floppy controller on the AHA-2742/2742-T. Installation of the
host adapter includes:
1. Installing the AHA (Adaptec Host Adapter) board
in an EISA system.
2. Installing the SCSI cable(s) and SCSI peripheral
External LED Connector
Floppy Connector (AHA-2742/2742-T only)
SCSI Channel A Internal Connector
Floppy Enable Jumper
(AHA-2742/2742-T only)
SCSI Channel B Internal Connector
(AHA-2740-T/2742-T only)
SCSI Channel A External Connector
Floppy Controller (AHA-2742/2742-T only)
Host Adapter BIOS
AIC-7770 Bus Master SCSI Chip
AIC-701 Configuration Chip
3. Terminating the SCSI bus.
4. Adjusting the host adapter configuration settings
if necessary.
Board Layout
Figure 1 shows the location of the major components on the host adapter; Table 1 provides a
description of each component.
J1 U1
U2 J4
Default Settings
Your host adapter is already configured for the
majority of EISA class computers. Table 2 lists the
default settings of your host adapter. Refer to
Section 6 , Configuring the Host Adapter for
information on changing any of these settings:
5. Loading software if necessary.
Table 2. Host Adapter Default Settings
Interrupt Level
Bus Release Time
Data FIFO Threshold
Host Adapter BIOS Address
Host Adapter SCSI ID
SCSI Bus Parity
SCSI Selection Timeout
SCSI Bus Reset at Power-on
SCSI Bus Termination
Greater Than 1 GByte Support
More Than Two Drive Support
Removable Drive Support
Default Setting
IRQ 11
Device ID 7
256 ms
Support removable
drive as boot device
The On-board Floppy Controller
(AHA-2742/2742-T only)
Figure 1. Host Adapter Board Layout
If your floppy diskette drives are already running under another controller, disable the
on-board floppy controller by removing the
jumper shunt on jumper J4.
To use the on-board floppy controller, leave the
jumper shunt installed on jumper J4 and then
disable your existing floppy controller; refer to
your computer or floppy controller user
Installing the Host Adapter
Board Installation
Turn OFF and disconnect power to the system and
external equipment. Always refer to your system’s
documentation for instructions on removing the
system cover and adding option boards.
1. Remove the cover of your EISA personal
computer to expose the EISA bus slots on the
2. Locate an unused EISA slot in your system which
supports bus master operations (refer to the
host system documentation for details) and
remove the corresponding slot cover.
3. Align and insert the host adapter in the EISA
slot. Secure the host adapter in your system.
Connecting Peripherals
Connecting Cables
SCSI devices are cabled together in a single
continuous daisy-chain of devices, called the
SCSI bus. SCSI Channel A and SCSI Channel B
(AHA-2740-T/2742-T only) can each accommodate
a SCSI bus with up to seven SCSI devices connected. SCSI Channel A is comprised of both an
internal and external connector.
Only Single-Ended SCSI devices are supported by the
AHA-2740/2742/2740-T/2742-T host adapters. Consult
your SCSI device user documentation.
Internal SCSI Cables
When connecting the 50-pin internal SCSI ribbon
cables to both the host adapter and internal SCSI
peripheral device(s), make sure that Pin 1
orientation is maintained throughout the bus.
Pin 1 of the SCSI cable is designated by a colored
stripe on one edge of the flat ribbon cable. Pin 1 of
the host adapter or SCSI device connector is
usually designated by a delta or arrow symbol (▲)
on the connector.
The internal connectors for SCSI Channel A and
SCSI Channel B (AHA-2740-T/2742-T only) use a
50-pin SCSI flat ribbon cable with a 50-pin header
internal connector.
External SCSI Cables
The external connector for SCSI Channel A uses a
50-pin shielded cable with a high-density external
connector. External cable connectors are keyed and
can only be plugged in one way; Pin 1 orientation is
Floppy Cables (AHA-2742/2742-T only)
The floppy connector uses a 34-pin floppy ribbon
cable with a 34-pin header connector. Make sure to
maintain Pin 1 orientation as previously described
in Internal SCSI Cables.
Enabling or disabling host adapter termination is
software selectable only. To disable termination on
the host adapter, refer to Section 6 , Configuring
the Host Adapter for instructions.
Select the Host Adapter
Terminating Other SCSI Peripheral Devices
Check the manufacturer’s documentation to
determine how to enable or disable SCSI bus
termination on your SCSI peripheral device(s).
SCSI ID Setting
For each device located on the SCSI bus, a unique
SCSI ID (0-7) must be reserved. The default value
for your host adapter is SCSI ID 7. Refer to Section
6 , Configuring the Host Adapter for instructions on
changing the SCSI ID for the host adapter. Refer to
the SCSI device documentation for information on
changing the SCSI ID on other SCSI devices.
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. Table 3 describes the three
possible SCSI device and host adapter (AHA)
Table 3. SCSI Device and AHA Configuration
Devices Connected To Host Adapter
AHA Termination
Internal devices only (AHA at end of cable)
External devices only (AHA at end of cable)
Internal and External devices (AHA in between)
Once the files have been copied, run the option in
the Configuration utility that allows you to
configure the EISA slot in which the host adapter
is installed. A screen listing the host adapter
parameters is displayed.
If your host adapter is an AHA-2740-T/2742-T, a set of
parameters for SCSI Channel B is displayed and can be
Configure the Host Adapter Parameters
Reassemble the System
Select values for each setting as instructed on the
screen’s menu.
Follow your system and SCSI device documentation to replace the system cover and connect all
system and SCSI device power cables.
Interrupt Level–selects the IRQ level of the host
Termination on the SCSI Bus
The first and last physical SCSI devices on the
ends of the SCSI bus must have a set of resistors
called terminators either installed or enabled. All
other SCSI devices installed between the ends of
the SCSI bus must have their terminators either
removed or disabled.
provide such an option, you can also use the DOS
Copy command to copy these files to the bootable
Configuration diskette.
Configuring the Host Adapter
A Configuration diskette containing an EISA
Configuration utility is normally supplied by the
EISA system vendor. Depending on the EISA
Configuration utility supplied with your system,
host adapter configuration will vary. The basic
steps involved in running the EISA Configuration
utility are explained in this section.
Run the EISA Configuration Utility
Place the bootable Configuration diskette in an
operative drive and reset the system to boot from
this diskette. Run the EISA Configuration utility
as instructed by the EISA system vendor.
Copying Files
The Configuration utility 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.ovl files from the
host adapter diskette to the bootable Configuration
diskette. If the Configuration utility does not
Bus Release Time–selects the EISA bus release
time used when the host adapter gets preempted in
bus master mode.
Data FIFO Threshold–selects the data FIFO
threshold percentage used by the host adapter.
Host Adapter BIOS Address–selects the base
BIOS address of the host adapter.
Host Adapter SCSI ID–selects the SCSI ID (0-7)
for the host adapter. SCSI IDs 0 and 1 should be
reserved for SCSI hard disk drives. Each installed
SCSI device must have a unique SCSI ID.
SCSI Bus Parity–allows you to enable or disable
SCSI bus parity on the host adapter.
SCSI Selection Timeout–selects the SCSI
selection timeout used by the host adapter during
the SCSI selection phase.
SCSI Bus Reset at Power-on–allows you to
enable or disable a SCSI bus reset generated by the
host adapter during its power-on initialization, and
after a Hard Reset.
SCSI Bus Termination–allows you to enable or
disable SCSI termination on the host adapter.
BIOS and SCSI Device Configuration–sets
BIOS and SCSI device options. Refer to the
following section for information on these options.
BIOS and SCSI Device Configuration
BIOS Configuration
This option allows you to configure the host
adapter BIOS.
Greater Than 1 GByte Drive Support–provides
a mechanism for using a hard disk with a capacity
greater than 1 GByte. If this option is enabled, the
following translation schemes are used:
Hard disks ≤ 1 GByte use a translation scheme
of 64 heads, 32 sectors per track
Hard disks ≥ 1 GByte use a translation scheme
of 255 heads, 63 sectors per track
More Than Two Drives Support–allows BIOS
to support more than two SCSI hard disks (supported by DOS 5.0 and above). If this option is
enabled, up to eight hard disks can be attached to
INT 13h.
Removable Drive Support–allows you to select
one of the following options for configuring
removable drive support:
Error if Device Not Found–selects whether the
operator will be notified if the BIOS is unable to
find the device during the boot procedure.
BIOS Support Option–allows devices attached to
the SCSI bus to be recognized by the host adapter
BIOS and installed as devices on the system
without the need for device driver software.
Send Start Command–is used for devices that
require a command to start up after power-on.
Most devices do not require this.
Initiate Synch Negotiation–allows the host
adapter to attempt to use the faster synchronous
protocol for data transfers on the SCSI bus. If deselected, the transfer will be done asynchronously,
unless a SCSI device itself requests synchronous
Enable Disconnection–allows the device to go
off-line while performing an operation. This allows
the host adapter to perform other operations on the
SCSI bus while the SCSI device is temporarily
Maximum Synch Transfer Rate–allows selection of the highest data transfer speed that the
host adapter will attempt with that peripheral. The
host adapter supports rates up to the Fast SCSI
maximum of 10 MBytes/second.
Disable removable drive support
When configuration of the SCSI devices is complete, save the configuration and exit the EISA
Configuration utility.
Support removable drive as boot device only
Support all removable drives
Two SCSI utilities are available with your host
Support for removable drives means only that the BIOS
allows for use of a removable drive as if it were a fixed
disk drive; it does not mean that the disk media can be
removed during operation.
Format Disk–accesses the Adaptec SCSI LowLevel Format utility. Most SCSI disk drives are
pre-formatted, and do not need re-formatting.
This option allows you to customize the configuration of the SCSI devices connected on the SCSI bus.
Select values for each setting as instructed on the
screen’s menu.
Host Adapter Diagnostics–runs a diagnostic on
your host adapter by doing DMA transfers between
the SCSI host adapter and system memory. You
should run this utility without any device drivers
or TSRs loaded. This test will run indefinitely until
Esc is pressed.
SCSI Device Configuration
Operating Environment Software
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.) Additional software is required if you
desire to do the following:
Support more than two hard disk drives under
versions of DOS prior to MS-DOS 5.0
Use devices other than hard disk drives such as
SCSI tape, CD-ROM, scanners, etc.
Treat removable media devices as removable
while your computer is running
Refer to the documentation received with your I/O
environment software package for instructions on
loading your SCSI I/O operating environment for
versions of DOS prior to MS-DOS 5.0.
Novell NetWare®, OS/2®, and UNIX®
Adaptec is working with major operating system
suppliers to provide embedded support in their
operating systems. Please contact Adaptec or your
operating system vendor for information on the
current schedule for I/O operating environment
software support.
System Will Not Boot From a SCSI Disk Drive
If both SCSI and non-SCSI disk 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 system’s CMOS Setup
is set to No Drives Installed, as is required for
SCSI host adapters.
2. Try enabling the BIOS Support Option in the
BIOS and SCSI Device Configuration
option. See Section 6 , Configuring the Host