Asus P2B-L User Manual page 30

11. Fast (50-pin)/Wide (68-pin)/Ultra2 (68-pin) SCSI Connectors
This motherboard has onboard 50-Pin Fast SCSI connector for 8-bit SCSI de-
vices, 68-Pin Wide SCSI connector for 16-bit SCSI devices, and 68-Pin Ultra2
SCSI connector for 32-bit SCSI devices.
P2B-L/S/LS Onboard SCSI Connectors
IMPORTANT: The 68-pin Wide SCSI Connector is always terminated and will
only work as an end device.
NOTE: Up to 15 devices can be connected with 50-Pin Fast-SCSI and 68-Pin Ultra-
Wide SCSI combined.
The onboard Adaptec AIC-7890AB chipset (optional) 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 (optional) 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.
PCI-to-Ultra2 (LVD)
LVD Mode
Adaptec AIC-3860 Chipset
P2B-L/S/LS Mixed Ultra2 and Single-Ended Device Configuration
Ultra2 SCSI uses the same connectors and cables as UltraSCSI, so upgrading is easy and cost-effective.
30 ASUS P2B-L/P2B-S/P2B-LS User's Manual
III. INSTALLATION
35
1
35
1
1
50-pin Fast SCSI II Connector
PCI Bus
Adaptec AIC-7890AB Chipset
Ultra2 SCSI Connector
L S
Wide SCSI Connector
SE Mode
68 68-pin Ultra2 SCSI Connector
34
68
68-pin Wide SCSI Connector
34
Ultra2 Devices
Disk 1 Disk 2 Disk 3
Single-Ended Devices
CD-ROM Scanner Tape