Adaptec AHA-2920 Installation Guide - Page 8

Multiple Host Adapters s Multiple SCSI host adapters can be installed in your computer; you are limited only by available system resources (e.g., I/O port and BIOS addresses). s Each host adapter you install forms a separate SCSI bus with a different set of SCSI devices. SCSI IDs can be reused as long as the ID is assigned to a device on a different host adapter (e.g., each host adapter can have a device with SCSI ID 0). Modifying PCI Parameters You may need to change the PCI configuration parameters in the computer's setup program if s your system CMOS setup requires you to enable PCI parameters. s your computer does not recognize the host adapter after you install it. s you cannot access any of the devices. Usually you start the setup program by pressing a specified key like Delete or F1 when your computer boots (refer to your computer documentation). Listed below are some things you may need to change in the setup program. Some configuration options apply to a specific PCI bus slot. Therefore, if you change these options, be sure you are applying them to the slot in which the host adapter is installed. Read your computer documentation if you are not sure which slot corresponds to each number. s If there is an Interrupt Type or Interrupt Line option in the setup program, be sure to select Int-A or Interrupt Type = A. Depending on your computer, you may also be required to change a motherboard jumper setting. s If there is a Triggering Interrupt option, be sure to select Level. s If there is an option to enable or disable individual PCI slots, be sure to enable the slot in which the host adapter is installed. s If your computer has a combination of ISA (or EISA) boards and PCI boards, you may need to mark the IRQs used by ISA/EISA boards as Used so the computer BIOS will not try to assign these IRQs to other PCI boards. s In some computers the BIOS reserves a set of available IRQs for PCI boards, and you have to assign these IRQs manually. Connecting to the LED Connector (Optional) Most computers have an LED disk activity light on the front panel. If you want the LED to light whenever there is activity on the SCSI bus, then disconnect the cable from the LED connector on the motherboard and connect it to the LED connector on the host adapter (the LED will no longer indicate non-SCSI, i.e., IDE, activity). On computers with a two-position LED cable, connect the LED cable to pins 1 and 2 of the LED connector. LED Cable Pin 1 1 LED Connector 7