Gateway ALR 9250R, User Manual

Page: 43 / 226

Chapter 2: System Features 29
Drive controllers and connectors
The system board supports several controllers and connectors for the
control of the various drives that are or can be installed in the system.
SCSI connectors
The system board includes two SCSI controllers. A narrow SCSI controller
(SYM53C810AE) is on the PCI-A bus, and a dual-channel wide LVD/SE
(Ultra2/Ultra) SCSI controller (SYM53C896) is on the PCI-B bus. The
narrow controller provides support for legacy 8-bit SCSI devices that may
be installed in the 5.25-inch drive bays. The wide controller drives one
SCSI backplane and provides support for external expansion.
Each controller has its own set of PCI configuration registers and SCSI I/O
registers. As a PCI 2.1 bus master, the wide controller supports burst data
transfers on PCI up to the maximum rate of 132 MB/sec using on-chip
buffers.
No logic, termination, or resistor loads are required to connect devices to
the SCSI controller other than termination in the device at the end of the
cable. The SCSI bus is terminated on the system board with active
terminators that can be disabled.
Wide SCSI A and Wide SCSI B connectors
Internally, each wide channel is identical, capable of operations using either
8- or 16-bit SCSI providing 10 MB/sec (Fast-10) or 20 MB/sec (Fast-20)
throughput, or 20 MB/sec (Ultra) or 40 MB/sec (Ultra-wide).
S VRM connector for processor 2 CC IDE connector
T VRM connector for processors 1 & 2 DD Diskette drive connector
U VRM connector for processor 1 EE Auxiliary power connector
V Processor 1 Slot 2 connector FF USB internal connector
W Main power connector, primary GG SMBus connector
X Processor 2 Slot 2 connector HH F16 expansion connector
Y Processor 3 Slot 2 connector II Narrow SCSI connector
Z Main power connector, secondary JJ External IPMB connector
AA Front panel connector KK SMM connector
BB Processor 4 Slot 2 connector LL Wide SCSI A connector
9250R.book Page 29 Friday, April 9, 1999 9:44 AM