Compaq AlphaServer ES45 Service Manual page 38

PCI modules are either designed specifically for 5.0 or 3.3 volt slots, or are
universal in design and can plug into either 3.3 or 5.0 volt slots.
CAUTION: PCI modules designed specifically for 5.0 volts or 3.3 volts are keyed
differently. Check the keying before you install the PCI module and
do not force it in. Plugging a module into a wrong slot can damage
it.
PCI Bus Implementation
•
Is fully compliant with the PCI Version 2.2 Specification.
•
Operates at delivering a peak bandwidth of 1.8 GB/sec; over 533 Mbytes/sec
for each 66 MHz bus and over 266 Mbytes/sec for the 33 MHz bus.
•
Has ten option slots (seven of which are hot swap).
•
Supports three address spaces: PCI I/O, PCI memory, and PCI configuration
space
•
Supports byte/word, tri-byte, quadword, and longword operations
•
Exists in noncached address space only
I/O Implementation
The system has 10 I/O slots, with six slots at 66 MHz and four slots at 33 MHz.
The Acer Labs 1543C chip provides the bridge from PCI 0 to ISA. The C-chip
controls accesses to memory on behalf of both P-chips.
I/O Ports
The I/O ports are shown in Section 1.6.
1-20 ES45 Service Guide