More About Scsi; The Scsi "Chain; Scsi Id Numbers; Scsi & Ide - Roland VS-880EX Application Manual

More About SCSI

SCSI is a high-speed data transmission bus that is often taken for granted thanks to its common use on
personal computers. However, insufficient attention to SCSI connections have turned out to be the major
cause of "mysterious" or intermittent performance problems users have experienced. Although SCSI has
received a reputation for being voodoo or black magic, most problems may be cured 100% by following
the suggestions outlined below.

The SCSI "Chain"

The SCSI specification allows for up to eight devices (computers, disk drives, etc.) to be "chained" together
on a single SCSI circuit. Cables are connected from one to the next and then the next, etc.; just like making
a chain.
The two physical ends of a SCSI chain must be terminated correctly. This also helps reduce reflection on
the bus. Incorrect termination will result in extra "ghost reflections" appearing on the SCSI bus, which can
also corrupt SCSI communications. One end of the SCSI chain is the VS-880EX. It is internally terminated
already. You must provide proper termination on the other end of your SCSI chain.
Remember: You only add termination to the LAST drive of the external SCSI
chain.

SCSI ID Numbers

Each disk or device in a single SCSI chain is identified by its SCSI ID number. This number from 0-7 (eight
devices total) is usually set by a switch on the rear panel of the device.
Each device must be set to a unique SCSI ID number. No two devices can
have the same number. The VS-880EX internal computer is set to SCSI ID # 7.
Use SCSI # 1-6 for your external devices. (If you have an internal SCSI hard
disk drive installed inside your VS-880EX, it will most likely be set to SCSI #
0.)
If you cannot find the SCSI ID selector switch, contact your device supplier for instructions to "set the SCSI
ID number."
SCSI & IDE
The VS-880EX actually contains two internal buses for communicating to disk devices - SCSI and IDE.
However, only the SCSI bus is available externally. If you purchased your VS-880EX with an internal disk
drive installed, it is most likely an IDE device and is connected to the internal IDE communication bus. It is
simple to identify your internal device.
1. Press the [SYSTEM] button repeatedly until the LCD displays "SYS Drive Select ? "
2. Press [YES].
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VS-880EX Application Guide
VS-880EX Disk drive 0 Disk drive 1 Disk drive 2