HP TC4100 - Manual (Page 52)

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Chapter 3 Installing and Configuring
9. PCI slot 2
10. PCI slot 1
11. Embedded LAN
IRQ Settings
The IRQ settings are automatically assigned and do not require user intervention. PCI boards have the capability
to share hardware interrupts (IRQs) with other PCI boards, as stated in the PCI specifications, but this does not
always prove to be true between board manufacturers.
The HP Server tc4100 provides various ways to automatically share interrupts in the Server. The sharing mode
can be selected under the heading “Sharing Algorithms” in the Setup Utility. The IRQs are automatically
assigned during boot up for each PCI slot and embedded device in the Server, avoiding any IRQ conflicts and
providing the best performance. This feature also provides a way of manually assigning IRQs when disabling
the Sharing Algorithm feature.
These IRQ assignments trigger the installed NOS to enable the APIC (Advanced Programmable Interrupt
Controller), which takes control of the IRQ sharing scheme. You are not required to manually assign interrupts
for the following NOSs:
• Microsoft’s NT 4.0
• Novell’s NetWare 5
• SCO UnixWare 7
System Board PCI Slots
All accessory boards plug into the six slots on system board at the rear of the Server’s chassis.
• Four PCI slots (Slots 3 - 6) support full length 32-bit boards at a clock rate of 33 MHz. These slots only
support +5 VDC power and Universal boards. These slots have keys in the upper half of the board slot to
prevent 3.3 volt boards from being inserted into the slots.
NOTE The Server can be configured to boot from a PCI accessory board or PCI-based DAC,
instead of the onboard SCSI channels, by putting the board in one of the PCI slots. The
SCSI Configuration Utility can be used to configure the Server to skip over the onboard
SCSI channels and select a PCI slot instead, when scanning for boot devices.
NOTE CO UnixWare 7 requires installation of the OSMP module to enable the APIC.
NOTE Universal boards automatically switch to accept power from a +5.0 or +3.3 VDC source
and have a key slot in the connector to allow installation in any of the 6 PCI slots.