Installation guide

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AHA-2840A/2842A Installation Guide
Part Number: 510590-00, Rev B
Print Spec Number: 492663-00
Current Date: 5/9/96 ECN Date: 6/3/96
if no SCSI hard disk drives are connected to the host
adapter, you can reduce bootup time if you disable
the host adapter BIOS.
Matching I/O Address and Slot Number
In EISA/VL-Bus systems, we recommend that the
host adapter I/O address match the number of the
VL-Bus slot in which the host adapter is installed.
(See your PC documentation to determine the slot
numbers.) If the host adapter is installed in slot #1
leave the I/O address at the default (1C00h); if it is in
slot #2, change the I/O address to 2C00h; if it is in
slot #3, change the address to 3C00h, etc.
Jumper Block
Leave the jumper on jumper block J5 installed unless
you are experiencing problems with write-back sig-
nals. (See Section 8, Troubleshooting Checklist.)
Connecting Peripherals
Setting SCSI IDs
You must assign a different SCSI ID to each device on
the AHA-2840A/2842A SCSI bus. See your SCSI
peripheral documentation for directions on how to
determine the ID and change it.
■ The default SCSI ID for AHA-2840A/2842A host
adapters is SCSI ID 7. You can change the ID with
the SCSISelect utility, if necessary. (See Section ,
Configuring the Host Adapter.)
■ We recommend that you assign SCSI IDs 0 and 1
to the first two SCSI hard disk drives in your PC.
Connecting Cables
SCSI devices are cabled together in a single, con-
nected series called the SCSI bus. The SCSI bus cables
must run sequentially from one device to the next,
with no branches.
The host adapter is at the end of the SCSI bus if
either the internal or external SCSI connector is
unused. The host adapter is in the middle of the bus
if internal and external SCSI devices are installed.
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