3. HARDWARE SETUP SCSI Connection and Termination Information Each SCSI channel is like a water hose where the inside must be opened and the ends must be closed. Each connector, whether 68 pins or 50 pins may have single or double-ended configurations. For Single-Ended configurations, the Termination for that particular channel must be set to Enabled in 4.4.3 PCI Configuration . For Double-ended configurations, the Termination for that particular channel must be set to Disabled in 4.4.3 PCI Configuration . Each channel may have up to 15 de- vices (ID#0-15, with #7 reserved for the chipset).
The onboard Adaptec AIC-7892B chipset (optional) incorporates an advanced multimode I/O cell that supports both single-ended (SE) and low voltage differential (LVD) devices. With Ultra160 devices, the SCSI bus platform performs at full Ul- tra160 speeds (up to 80 MB/sec in 8-bit mode and up to 160 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 LVD and SE devices, the onboard host adapter can be coupled with the Adaptec AIC-3860Q 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. Connectors 3. H/W SETUP NOTE: Ultra160 devices do not have termination jumpers so a terminator block on the SCSI cable is needed. If your end devices have its own termination, you may use it instead.
SCSI Connection Examples P3C-LS/L/S Mixed LVD and Single-Ended Device Configurations ASUS P3C-L / P3C-S / P3C-LS User’s Manual 51 Ultra1 Conn P3C-LS / L / S Adaptec AIC-7892B Chipset Bus Wide SCSI PCI L PCI-to-Ultra3 (LVD) LVD Mode Ad AIC- Ch LVD Devices Disk 1 Disk 2 Disk 3 60 SCSI ector Single-Ended Devices Connector CD-ROM Scanner Tape S SE Mode aptec 3860Q ipset Bu PCI