This FAQ document is valid for the following Symbios Logic devices: 53C810,
53C810A, 53C815, 53C825, 53C860 and 53C875. Many OS/2 installation problems
are due to IRQs not being enabled properly. The subsequent sections will
guide the reader through common setup steps to enable IRQs and general OS/2
driver questions.
Most OEM cards that use our chipsets are not "TRUE" plug and play PCI-SCSI Host
Adapters, that is why the manual settings of the IRQ in the system is required.
System CMOS setup hints:
The following section describes setup steps to take with 3 common System CMOSs.
These are general procedures, since each Mother Board Vendor modifies the BIOS
to configure their Mother Board. To get the best results. it is best to set Network cards to IRQ 9. This can be done via the software that comes with the card. Also set Sound cards to use IRQ 5.
Award BIOS
1) While in the CMOS setup pick the "PCI Configuration Setup" or "PNP and PCI
Configuration" menu. Change the settings for the slot number in which the Symbios
Host Bus Adapter (HBA) is located if this option is available from "Auto Detect"
to "INT A" or to an IRQ such as 10, 11, 12 or 15, leaving all other slots set to
Auto. If there are no Slot options available then use the "MANUAL" setting. This
will show all of the IRQs and will list them as either "Legacy ISA" or "NO/ICU" or
"PNP/PCI" or "Yes/ICU". What you will do is set all IRQs below 9 to either Legacy
ISA or NO/ICU. IRQ's 10, 11, 12 and 15 will be set to PNP/PCI or Yes/ICU.
2) The "Available IRQ" settings should be modified to 1st = 10, 2nd = 11,
3rd = 12, and 4th = 15. Ensure that any other device in the system (i.e., sound
card or LAN card) are not set to the same IRQs as the Symbios Logic HBA. For example, if the LAN card is using IRQ 11, remove IRQ 11 as the 1st available IRQ
in the CMOS setting and shift all of the available IRQs up one level.
3) Some versions have a statement that will say "PCI IRQ Activated by" set this
to Level. Some versions have a statment that will say "PCI IDE MAP to" set this to
ISA or Absent.
4) Save the configuration and reboot OS/2. If you see the OS2CAM.ADD driver
initialize the device and the desk top appears then you system is configured properly.
AMI BIOS
1) While in the CMOS setup pick the "Chipset" or "Advanced" menu.
2) Some versions of the CMOS setup allow for the setting of IRQs referenced to
the slot location of the Symbios Logic HBA. Other versions of the CMOS setup
only allow for the IRQ to be set to "PCI/ISA" or "Used/Available". In any case,
make sure that IRQ 9 is set to "Used", "not available", or "ISA". Keep IRQs 10,
11, and 15 free.
3) Save the configuration and reboot OS/2. If you see the OS2CAM.ADD or the
SYM8XX.ADD driver initialize the device and the desk top appears then you system
is configured properly.
Phoenix BIOS
If you have the version of the Phoenix BIOS, that only has 2 pages to the CMOS
setup and the only option for the SCSI is to enable or disable it. There is not
much that can be done other than this. The system will do an Auto setting on its
own. There is NO work-around to fix the problem. The only solution is to go to