Choosing a hard disk11
Choosing a hard disk11
Choosing a hard disk
11
Choosing a hard disk
Consider the following disk specifications when shopping for a hard disk for your
CBX-D3 system.
SCSI
For a general introduction to SCSI, see “SCSI” on page 3.
Setting up a SCSI daisy chain involves a little more than just making connections. Each
SCSI device must be assigned an ID number, and the daisy chain must be terminated
correctly. Details are explained in the following three sections, “SCSI cables,” “SCSI ID
setting,” and “SCSI termination.”
When using a SCSI daisy chain, bear the following points in mind.
•
Each device must have a unique SCSI ID number.
•
The SCSI bus must be correctly terminated.
•
Use quality cables and keep the length down.
•
Use the wire clips (or screws) on the SCSI connectors to secure the cable
connections.
•
All devices connected in the daisy chain must be switched on.
•
Never switch off or disconnect a device once the system is running.
Specification
Check
Notes
Is it compatible with your computer?
It may be advertised as compatible, or your
dealer may recommend it.
Does it have two SCSI connectors?
You need two to continue the SCSI daisy chain.
Are the SCSI connectors 25-pin D-SUB
or 50-pin Amphenol?
Macintosh computers are fitted with a 25-pin
D-SUB connector, while most other SCSI devices
use a 50-pin Amphenol connector.
Are the SCSI cables supplied?
If not, you will need to purchase these separately.
Can the SCSI ID be set from 0 ~ 7?
(For Macintosh, you only need 0 ~ 6)
If not, it might clash with another device's ID, in
which case you may have to rearrange the ID
numbers of some other SCSI devices in the
chain.
Does it have internal or external
termination?
External terminators are normally connected to
the rear of the SCSI device. If the device has an
internal terminator, make sure it can be switched
off so that any device can be positioned at the
end of the SCSI daisy chain.
Access time?
Measured in milliseconds, this is an indication of
how fast data from different areas of the disk can
be retrieved. The maximum we recommend is
30ms. Access times slower than this will degrade
the performance of the CBX-D3.
Data transfer rate?
Usually measured in megabytes per second
(MB/sec), this indicates how fast data can be
written to and read from the hard disk. The
minimum we recommend is 1MB/sec. A transfer
rate less than this will degrade the performance
of the CBX-D3.
NOTE:
Switch off all your equipment before making any SCSI connections.
