III.INSTALLATION

22.50 pin Narrow/68 pin Wide/68 pin Ultra2 SCSI Connectors

This motherboard has onboard 50-Pin Narrow SCSI connector for 8-bit SCSI devices, 68-Pin Wide SCSI connector for 16-bit SCSI devices, and 68-Pin Ul- tra2 SCSI connector for 16-bit differential SCSI devices.

 

35 1

68-pin Wide

 

 

SCSI Connector

 

68 34

 

 

50-pin Narrow

 

1

35

 

 

 

SCSI Connector

 

 

 

68-pin Ultra2

SCSI Connector

P2B-D2 Onboard SCSI Connectors

68 34

NOTE: A maximum of 15 devices can be connected using any combination of 50- pin Narrow SCSI, 68-pin Wide SCSI, and 68-pin Ultra2 SCSI devices.

The onboard Adaptec AIC-7890AB chipset incorporates an advanced multimode I/O cell that supports both single-ended (SE) and Ultra2 devices. With Ultra2 devices, the SCSI bus platform performs at full Ultra2 speeds (up to 40 MB/sec in 8-bit mode and up to 80 MB/sec in 16-bit mode) and extended cabling 12m (or 25m in a point-to-point configuration). When an SE device is attached, the bus defaults to an SE speed and cable length.

In mixed environments of Ultra2 and SE devices, the onboard host adapter can be coupled with the Adaptec AIC-3860 transceiver chipset to bridge the compatibility gap. By dividing the SCSI bus into independent SE and low voltage differential (LVD) segments, the transceiver chipset supports legacy devices without limiting performance and cable length on the LVD segment.

IMPORTANT: Connect SCSI devices as shown. Mixing SCSI devices will lower performance.

68-pin Wide

Disk 1 Disk 2 Disk 3

INSTALLATION

Connectors

III.

 

 

 

50-pin Narrow

(Terminated)

CD-ROM Scanner Tape

(Terminated)

68-pin Ultra2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Disk 1

 

Disk 2

 

Disk 3

 

 

Terminator

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P2B-D2 SCSI Connection

NOTE: Ultra2 devices do not have termination jumpers and must use a separate terminator on the last connector.

ASUS P2B-D2 User’s Manual

33