OTARI RADAR II, Operation Manual, Page: 194 / 261

8.1.2 SCSI Basics
SCSI (Small Computer System Interface) is a specification used for transmitting
data between a main computer host and various peripherals. It allows all the parts of
a computer system to communicate with one another. In our case, RADAR II is the
computer host and the peripherals are internal and external hard disk drives, and
perhaps a tape backup unit.
The SCSI specification allows the host (RADAR II) to address up to 7 separate
devices. Depending on the system configuration, not all of these devices (SCSI ID’s)
will be available for the tape backup unit; however a typical RADAR II system (one
internal hard disk, one internal SCSI controller) has five free SCSI IDs.
Each SCSI device has an identification number assigned to it that falls between 0
and 7. On stand alone SCSI devices this is usually set using a hardware switch.
RADAR II's internal SCSI number assignments are set at the factory. SCSI
peripheral devices generally have two 50 pin connectors: an in and a thru. This is
done to allow chain connection of multiple devices. RADAR II is the host and as
such needs only one connector.
Connected to the last device in a SCSI chain is a terminator plug. Physically, it
looks like a SCSI connector without a cable and it electrically completes the loop
connection between all the devices in the chain.
IMPORTANT!
The SCSI terminator's importance cannot be overstated - this must be
connected for SCSI communication between RADAR II and any
external devices to occur. If it is left unconnected, there is the danger of
losing audio files or corrupting RADAR II's file system.
See §2.3 for more information on installing the terminator plug.
B A C K U P & R E S T O R E O P E R A T I O N 8-3
Edition 1