Intergraph InterRAID-12, Hardware User'S Manual

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Cache Memory
The cache memory subsystem on the RAID controller board has a total of
8 MB of DRAM.
PCI Connector
The PCI connector inserts into the PCI slot of the server system board. This connector
carries all the PCI bus signals between the RAID controller board and the system board.
Flash EEPROM (MegaRAID Only)
Flash EEPROM stores the RAID firmware programs and the RAID configuration data.
Since it is re-writeable, it allows the firmware to be upgraded without replacing any
hardware. As the disk configurations change (for example, when a drive fails) the flash
EEPROM records the changes. The flash EEPROM retains the firmware and configuration
data after the system is powered off.
SCSI Controller
To manage the data flow on the RAID SCSI bus either two or three SCSI controller are used:
Two 53C720 controllers for DAC960P, three 53C720 controllers for DAC960PD, or three
53C770 controllers for MegaRAID. One SCSI RAID controller is assigned to each bus
channel.
External RAID SCSI Connector (DAC960PD and MegaRAID)
The external RAID SCSI connectors for DAC960PD and MegaRAID are 68-pin ultra high
density connectors.
Onboard Speaker (MegaRAID Only)
The MegaRAID controller has an onboard tone generator for audible warnings when system
failures occur.