Yamaha A4000 Owner's Manual page 252

Installing Optional Equipment
[Procedure]
1.
Use SCSI cables to daisy-chain the external SCSI devices.
• There are several types of SCSI connector. Use SCSI cables appropriate for your devices.
2.
Connect the power cable of the external SCSI device to an AC outlet.
3.
Set the SCSI ID (0 — 7) of the external SCSI device.
• Select a SCSI ID that will not conflict with the other SCSI devices (including the A5000/A4000). When
the A5000/A4000 is shipped from the factory, the SCSI ID is set to 6. When installing the internal hard
disk, we suggest that you set the internal hard disk to a SCSI ID of 4.
4.
Attach the terminator to the SCSI connector (the vacant one of the two SCSI connec-
tors) of the last device in the daisy-chain.
Alternatively, turn on the terminator switch of that device.
5.
Make sure that the terminator switch is turned OFF for all other devices in the daisy-
chain (i.e., all devices other than the last device).
• When a new hard disk, MO disk, or other removable media (or a disk which was previously used on a
computer or other equipment) is connected to the A5000/A4000, it will be necessary to format (page
177), create volumes (page 172), and mount (page 173) the disk after making all necessary audio,
MIDI, and SCSI connections to the A5000/A4000 (and, in the case of removable media, after inserting
the disk in the appropriate drive).
• Many articles and books concerning SCSI are available. However most of them discuss only the con-
cepts or the specification, and do not tell you what to do if the system does not work when connected
as described. The following paragraphs will provide more information about SCSI that will help you cor-
rect problems which may occur when SCSI devices are connected. Please read this material if you
experience problems. Please be aware that when connecting SCSI devices, problems with termination
and cabling can cause valuable data to be damaged. We regret that Yamaha can take no responsibility
regarding any data which is lost.
Realities of terminator installation
Although we have said that a terminator is required at the beginning and end of the SCSI bus, this is a
general principle and not a requirement. For example if the bus is extremely short (45 cm or less),
there are cases in which it is best for there to be a terminator only on one or the other end. This is
something which you should be aware of when using recent ultra-miniature drives. However if other
drives are connected in addition to these drives, the situation will again be different.
Also, if the SCSI devices are separated by more than 3 meters, it is said that using a terminator at the
3 meter point is preferable. In this case, three or more terminators will exist within the SCSI bus.
In this way, the theory and practice of SCSI connections can differ widely. Simply changing a drive in a
system that had been working correctly can cause operation to become unreliable, or adding a drive to
an unreliable system can cause it to start working correctly. In practice, a certain amount of trial and
error is necessary.
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Appendix
• A5000/A4000
Important
Note