NAME

     bt — Buslogic/Mylex MultiMaster SCSI host adapter driver

SYNOPSIS

     To compile this driver into the kernel, place the following lines in your kernel
     configuration file:

           device isa
           device scbus
           device bt

           In /boot/device.hints:
           hint.bt.0.at="isa"
           hint.bt.0.port="0x330"

DESCRIPTION

     This driver provides access to the SCSI bus connected to a Buslogic/Mylex MultiMaster or
     compatible controller:

           MultiMaster "W" Series Host Adapters:

           Adapter   Bus   Commands  Description
           BT-948    PCI     192     Ultra SCSI-3
           BT-958    PCI     192     Wide Ultra SCSI-3
           BT-958D   PCI     192     Wide Differential Ultra SCSI-3

           MultiMaster "C" Series Host Adapters:

           Adapter   Bus   Commands  Description
           BT-946C   PCI     100     Fast SCSI-2
           BT-956C   PCI     100     Wide Fast SCSI-2
           BT-956CD  PCI     100     Wide Differential Fast SCSI-2
           BT-445C   VLB     100     Fast SCSI-2
           BT-747C   EISA    100     Fast SCSI-2
           BT-757C   EISA    100     Wide Fast SCSI-2
           BT-757CD  EISA    100     Wide Differential Fast SCSI-2
           BT-545C   ISA      50     Fast SCSI-2
           BT-540CF  ISA      50     Fast SCSI-2

           MultiMaster "S" Series Host Adapters:

           Adapter   Bus   Commands  Description
           BT-445S   VLB      30     Fast SCSI-2
           BT-747S   EISA     30     Fast SCSI-2
           BT-747D   EISA     30     Differential Fast SCSI-2
           BT-757S   EISA     30     Wide Fast SCSI-2
           BT-757D   EISA     30     Wide Differential Fast SCSI-2
           BT-545S   ISA      30     Fast SCSI-2
           BT-542D   ISA      30     Differential Fast SCSI-2
           BT-742A   EISA     30     SCSI-2 (742A revision H)
           BT-542B   ISA      30     SCSI-2 (542B revision H)

           MultiMaster "A" Series Host Adapters:

           Adapter   Bus   Commands  Description
           BT-742A   EISA     30     SCSI-2 (742A revisions A - G)
           BT-542B   ISA      30     SCSI-2 (542B revisions A - G)

     Tagged queueing is supported on 'W' series adapters, 'C' series adapters with firmware of
     rev 4.42 and higher, and 'S' series adapters with firmware of rev 3.35 and higher.

     Boards with certain firmware revisions may lock up under heavy load to certain devices,
     especially if tagged queueing is used.  Should you encounter a problem with your adapter,
     contact Mylex technical support and ensure you have the latest firmware for your controller.

HARDWARE

     The bt driver supports the following BusLogic MultiMaster “W”, “C”, “S”, and “A” series and
     compatible SCSI host adapters:

     •   BusLogic BT-445C
     •   BusLogic BT-445S
     •   BusLogic BT-540CF
     •   BusLogic BT-542B
     •   BusLogic BT-542B
     •   BusLogic BT-542D
     •   BusLogic BT-545C
     •   BusLogic BT-545S
     •   BusLogic/BusTek BT-640
     •   BusLogic BT-742A
     •   BusLogic BT-742A
     •   BusLogic BT-747C
     •   BusLogic BT-747D
     •   BusLogic BT-747S
     •   BusLogic BT-757C
     •   BusLogic BT-757CD
     •   BusLogic BT-757D
     •   BusLogic BT-757S
     •   BusLogic BT-946C
     •   BusLogic BT-948
     •   BusLogic BT-956C
     •   BusLogic BT-956CD
     •   BusLogic BT-958
     •   BusLogic BT-958D
     •   Storage Dimensions SDC3211B / SDC3211F

     AMI FastDisk Host Adapters that are true BusLogic MultiMaster clones are also supported by
     the bt driver.

SEE ALSO

     cd(4), da(4), sa(4), scsi(4)

HISTORY

     The bt driver first appeared in the 386BSD patch kit.

AUTHORS

     Julian Elischer wrote a driver for the Multimaster cards that appeared in the 386BSD patch
     kit.  The driver was rewritten by Justin T. Gibbs to take advantage of new board features
     and work with the CAM SCSI framework in FreeBSD 3.0.

     Special thanks to Leonard N. Zubkoff for writing such a complete and well documented
     Mylex/BusLogic MultiMaster driver for Linux.  Support in this driver for the wide range of
     MultiMaster controllers and firmware revisions, with their otherwise undocumented quirks,
     would not have been possible without his efforts.