Compaq AlphaServer ES40 - PCI Backplane; IO Control Logic

1-18 Compaq AlphaServer ES40 Service Guide
1.9 PCI Backplane
The PCI backplane has two independent 64-bit, 33 MHz PCI buses that
support 64-bit PCI slots. The 64-bit PCI slots are split across the two
buses. The PCI buses support 3.3 V and 5 V options.
Figure 1–10 I/O Control Logic
PK-0319A-98
P-chip 0
Flash ROM
Interrupts
Acer Labs
1543C Chip
Config
(NVRAM functions)
P-chip 1
Keyboard
Mouse
CD-ROM
USB
COM1
COM2
Modem
Printer
Floppy
PCI 0
PCI 1
PCI Slot
PCI Slot
C-chip
(4) or (3)
(6) or (3)
NOTE: No USB options are currently supported.