Refer to Appendix D, EISA Free-Form Data for the initial SCSI subsystem datastructure.Configuration Byte Description and DefaultsThe following describes the SCSI device configuration byte format. Firmware defaultvalues are also given. These defaults are used by the firmware to interface with thevarious targets in the event that no Initialize SCSI Subsystem command has been re-ceived by the host adapter.Byte 0Bit 7 - Allow removable media in BIOS disk scanThis bit is used by the host adapter BIOS only, it does not affect operation. When thisbit is set, the BIOS will include a removable media device in the scan for devices tosupport under Int 13h.NoteThis feature does not support removal or exchange of the media. The drive istreated as a fixed media drive only. This is primarily intended to allow boot from aremovable media disk drive.Bit 6 - More than one LUN supportedThis bit is used by the host adapter BIOS only. When set, this bit indicates that thetarget will support more than one LUN. In the default state, only LUN 0 is supportedfor each SCSI target.Bit 5 - Parity Check enableWhen set, parity will be generated and checked. When cleared, parity will be gener-ated but not checked. By default, parity checking is enabled for all targets.Bit 4 - Send Start commandThis bit is used by the host adapter BIOS only. When set, the BIOS will send a StartStop Unit SCSI command to the target after a Test Unit Ready command returns acheck condition and reports a not ready status. The Start Stop Unit command will setthe Immed and Start bits and will clear the LoEj bit as defined in the SCSI 2 specifi-cation. By default, this feature is disabled for all targets.Bit 3 - Synchronous Negotiation enableWhen set, the host adapter will initiate synchronous negotiation with this target.When cleared, the host adapter will not initiate negotiation, but will respond if thetarget initiates negotiation. Default is to initiate synchronous negotiation with alltargets.Bit 2 - Disconnection enableWhen set, the host adapter will allow disconnection to occur with this target by set-ting the Allow Disconnection bit in the ID Message. When cleared, the AllowDisconnection bit will be cleared. By default, disconnection is enabled for all targets.EISA-to-Fast SCSI Host Adapter Hardware Functional Description4-29
