Choosing A Hard Disk; Scsi - Yamaha CBX-D5 Operating Manual

14 14 14 Chapter 5 : Connecting Hard Disk Drives Chapter 5 : Connecting Hard Disk Drives Chapter 5 : Connecting Hard Disk Drives

Choosing a hard disk

If you plan to buy a hard disk that is not listed on the supplied card, the following
specifications should be checked first.

SCSI

For an general introduction to SCSI, see "SCSI" on page 3.
Setting up a SCSI daisy chain requires a little more than just making connections. SCSI
devices require ID numbers and the daisy chain must be terminated correctly. These are
explained in the following three sections, "SCSI cables", "SCSI ID setting", and "SCSI
termination".
When using a SCSI daisy chain, the following points should be borne in mind.
• Allocate each device its own SCSI ID number.
• Terminate the SCSI bus correctly.
• Use quality cables and keep the length down.
• Use the little wire clips (or screws) on a SCSI connector to fasten the cable plugs
• All devices connected in the daisy chain must be switched on to use the system.
• Never switch off, or disconnect a device once the system has been switched on.
Specification
Is it compatible with your computer?
Does it have two SCSI connectors?
Are the SCSI connectors 25-pin
D-SUB, or 50-way Amphenol?
Are the SCSI cables supplied?
Can the SCSI ID be set from 0 ~ 7? (for
Macintosh you only need 0 ~ 6)
Does it have internal or external
termination?
Access Time?
Data Transfer Rate?
securely.
NOTE: Switch off all your equipment before making any SCSI connections.
Check
Maybe it is advertised as compatible, or your
dealer recommends it.
You need two to continue the SCSI daisy chain.
Macintosh computers are fitted with a 25-pin
D-SUB connector, while most other SCSI devices
have a 50-way Amphenol connector.
If not, you will need to purchase them separately.
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.
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.
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. An access time slower than this may affect
the performance of the CBX-D5.
Usually measured in Megabits per second
(Mbit/s), this shows how fast data can be written
to and read from the hard disk. The minimum we
recommend is 16Mbits/s. A transfer rate less than
this may affect the performance of the CBX-D5.
Notes