Yamaha A5000 Owner's Manual - Page 251

Installing Optional Equipment Connecting external SCSI devices This section explains how to connect external devices such as external hard disk drives, MO drives, or CDROM drives. About SCSI SCSI (pronounced "scuzzy") stands for Small Computer System Interface, and is a data transmission interface standard used by personal computers and other devices. The A5000/A4000SCSI interface allows convenient connection of internal and/or external hard disk drives, MOD drives, CD-ROM drives, and other SCSI-compatible devices. Up to 7 devices can be connected to the SCS "bus," including an internal SCSI drive. Most external SCSI devices have two SCSI terminals, allowing a number of devices to be "chained" together. Devices chained together in this can normally be connected in any order. The last device in the chain must be "terminated," either with a terminator unit plugged into the open SCSI connector, or by turning the device's internal terminator on (if available). The first device in the chain must also be terminated, but in the case of the A5000/A4000 this can be accomplished either with the terminator switch on the main circuit board, or the terminator switch/jumper on an internal hard disk unit. When an internal hard disk is installed A5000/ A4000 Internal HD indicates the terminator (or a terminator switch that is turned on). Devices which are not indicated by this symbol must not have a terminator attached to them. (Alternatively, their terminator switch must be turned off.) Main Unit Circuit Board External SCSI device External SCSI device External SCSI device When an internal hard disk is not installed A5000/ A4000 Factory default Main Unit Circuit Board External SCSI device External SCSI device External SCSI device Important • Before connecting SCSI devices, be sure to turn off the power of the A5000/A4000 and all connected equipment. If the power is on while connections are being made, the A5000/A4000 or SCSI devices can be damaged. • Including the A5000/A4000, each SCSI device is distinguished by a number from 0 - 7, called the SCSI ID. If two or more devices have the same SCSI ID number, the SCSI devices will not function correctly. When shipped from the factory, the A5000/A4000 is set to SCSI ID 6. Be aware that the SCSI ID number of a device has no relation to its position in the daisy-chain. • Don't forget to attach a terminator to the last SCSI device in the daisy-chain. • If an external SCSI device is not connected, it is not necessary to attach a terminator to the external SCSI connector of the SCSI interface board. • Use as short a SCSI cable as possible. Using long cables can cause unreliable operation. (In general, the total cable length including the cables inside the A5000/A4000 should be less than 6 meters (approximately 18 feet).) • Use good-quality SCSI cables. Poor-quality cables can cause unreliable operation. • Hard disks, MO disks, and other removable media will be formatted by the A5000/A4000. If you wish to use a hard disk, MO disk, or other removable media that was being used by a computer, you will need to perform the format operation after connecting and powering-on the disk. • Some SCSI devices have only one SCSI connector. If you are using such a device, connect it at the end of the daisy-chain. 251 q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q A5000/A4000 • Appendix