Sun Microsystems SunSwift SPARCserver 1000, Service Manual

Page: 209 / 218

Glossary-7
Reset Switch
This switch is behind the front panel. When pressed, it resets the system.
Root Disk
The root disk is the disk drive where the operating system resides. This drive is
in the SCSI tray that is located behind the front panel.
SBI (SBus Interface)
The SBI implements the interface between the SBus and the XBus. There is one
SBI on each system board.
SBus
Located on the system board, this bus connects up to three optional SBus cards
to the SBus Interface controller (SBI), which connects (in turn) interfaces with
other busses on the system board.
SBus card
Any of a large number of available cards providing optional features to the
system. Three SBus connectors are present on every system board.
SBus clock
The SBus operates at 20 MHz for SPARCserver 1000, and 25 MHz for
SPARCserver 1000.
SCSI Tray
This tray can hold up to six SCSI-2 devices and the control card. The chassis
accommodates one SCSI device tray.
SIMM (Single In-line Memory Module)
Sixteen SIMM sockets reside on the system board. A SIMM consists of control
circuitry and numerous DRAMs. SIMMs are 8- or 32 Mbyte. See also NVSIMM.
Status Registers
Three status registers reside on the system board. These registers monitor
LEDs, reset status, fan-, temperature- and DC/AC power conditions. Board
and processor ID are also monitored in these read-only registers.
SuperSPARC Module
This 3x5-inch card contains one SuperSPARC processor, cache memory, and a
cache controller. Note that main memory (SIMM groups) reside elsewhere on
the system board. A system board can have two SuperSPARC modules. A
SPARCserver 1000 system can have up to four such boards equaling eight
modules.