121
6 HP BIOS
BIOS Addresses
There are three major interrupt modes available:
•
PIC mode
This “Legacy” mode uses only the interrupt controllers. This mode can be
selected upon installation of Windows NT.
•
Virtual wire mode
This mode is implemented using the 82C59 interrupt and the I/O APIC
controller and is used during boot time. The virtual wire mode allows the
transition to the “symmetric I/O mode”.
•
Symmetric I/O mode
This mode is implemented using the I/O APIC controller.
NOTE
In “PIC mode” and “virtual wire mode”, the PCI interrupts are routed to the
INT line. In the “symmetric I/O mode”, the PCI interrupts are routed to the
I/O APIC controllers and forwarded over an GTL bus to the processor.
PCI Interrupt Request Lines
PCI devices generate interrupt requests using up to four PCI interrupt
request lines (INTA#, INTB#, INTC#, and INTD#).
PCI interrupts can be shared; several devices can use the same interrupt.
However, optimal system performance is reached when minimizing the
sharing of interrupts. Refer to
page 74
for a table of the PCI device
interrupts.
Summary of Contents for Vectra VL800
Page 1: ...hp vectra vl800 desktop minitower technical reference manual www hp com go vectrasupport ...
Page 26: ...26 1 VL800 Desktop Documentation ...
Page 44: ...44 2 VL800 Minitower Documentation ...
Page 122: ...122 6 HP BIOS BIOS Addresses ...
Page 138: ...138 7 Tests and Error Messages Error Message Summary ...