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"

DEPRECATION NOTICE

       This driver is scheduled for removal prior to the release of FreeBSD 13.0.

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-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-545S      ISA     30           Fast SCSI-2
             BT-542D      ISA     30           Differential Fast SCSI-2
             BT-542B      ISA     30           SCSI-2 (542B revision H)

             MultiMaster "A" Series Host Adapters:

             Adapter      Bus     Commands     Description
             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-946C
       •   BusLogic BT-948
       •   BusLogic BT-956C
       •   BusLogic BT-956CD
       •   BusLogic BT-958
       •   BusLogic BT-958D
       •   Storage Dimensions SDC3211B / SDC3211F

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.

Debian                                           August 18, 2020                                           BT(4)