BusLogic BT-64x - General Information

OS/2 BusLogic Switches

MultiMaster Device Drivers

LED Operation
Drive Power Connector
Primary Controller in Non-IML System
Term Power Fuse
Multitasking
SDC Drivers


LED Operation

When power is first applied to the BT-640A, an on-board diagnostic routine is run to verify that the major functional components of the board are operating correctly. The bus master chip, the SCSI controller chip, the firmware PROM, the local RAM and internal data buses are tested. Results of the tests are indicated by an LED on the board.

The LED will first turn on when power is applied. If the diagnostics find no malfunctions, the LED will then go off. In normal operation, the LED will be illuminated when command or SCSI bus activity occurs on the board. If an error is detected by the diagnostics, the LED will repeatedly flash a specific number of times, with a long pause between flashes, to indicate the board function which failed. This will continue until the board is powered down or reset. Failure interpretation from the number of flashes is as follows:

Flashes 640A-646S/D Failure
Always On Not operating/missing terminator
1 Firmware ROM checksum failure
2 Local RAM test failure
3 SCSI controller / interface failure
4 Internal data bus failure
5 Internal address bus failure
6 Bus master chip failure
7 SCSI drive type mismatch*
Constant Fuse Blown

* Applicable to the BT-646 when SE SCSI drivers are connected to the differential SCSI bus.


Disk Drive Power Connector

A 4-pin disk drive power connector (J4) is located at the top edge of the BT-64x board next to the SCSI connector Jl. This connector provides +12V and +5V power.

Note: The BT-64x brings the 12 volt power supply to the 4-pin power connector (14) via three gold fingers on the edge connector. The power rating of the Micro Channel edge connector on the12 volt is one ampere per finger. Consequently, the maximum power allowed from the 12 volts (Pin 1 of J4) is three amperes. Because certain large SCSI drives may require more than three amperes when their motors are spinning up, BusLogic recommends that this connector not be connected to these large SCSI drives.

Based on the power rating of the SCSI drives, if is recommended that this power connector not be daisy chained to multiple drives.


Term Power Fuse

SDCxx11x and BT-64x use a Microlite Little Fuse 27301.5 125 V 1.5 A (or equivalent micro fuse). It is difficult to see that the fuse is blown so you will need to use a VOM to test for continuity. The fuse can blow if termination power settings are not correct on the SCSI devices or if you disconnect the SCSI cables while the card or SCSI devices have power. (Ed. Sure ain't kidding!)


Primary Controller in Non-IML System

Enable the BIOS. Set your boot drive to ID0 or the BT-64x will not be able to boot from it. Also, you should set the boot drive to "autostart" so it spins up as soon as the system is turned on. I had a 0662 set to ID0, but the BT-646 complained about Target 0, LUN 0 not being detected, but then showed the 0662 at ID0, then the CD at 6,0. After jumpering the 0662 to autostart, everything was fine.


Multitasking Operation

For operating systems such as UNIX, NetWare, and OS/2, the mailbox protocol of the BT-64x provides true multitasking operation. Through the use of a mailbox structure, the BT-64x can support up to 255 tasks with minimum host processor intervention. Onboard firmware controls all of the SCSI activity that a task requires, including the Arbitration, Selection, Disconnection, Reconnection, and command completion status. This same mailbox protocol supports both initiator and target mode operation permitting high speed host-to-host communication and scatter-gather data transfers.


Disk > 1 GB and not SC0 UNIX

In the DOS environment, INT 13 calls are routed through the BT-64xA/S/D’s ROM BIOS. This on-board BIOS intercepts host interrupt 13H calls and dispatches a command to the BT-64x for all host to SCSI disk accesses. When the >lGB option is turned on, the BT-64x BIOS can access up to 8 GBytes per disk. Otherwise, it can only access the first 1 GBytes even if the formatted disk capacity is greater than 1GByte. This 1GByte restriction does not apply to other operating systems, such as NetWare, UNIX, SC0 UNIX 3.2.4, or OS/2 if the operating system can boot without accessing > 1 GBytes. If the operating system’s bootable image resides below 1 GBytes then it can boot via Interrupt 13H. Once any of these operating systems are booted, the disk accesses are not routed through Interrupt 13H and the operating system can access the entire disk space even if the > 1 GB option is not turned on.

Under SC0 UNIX 3.2.2, the >lGB option must be turned off because the operating system itself has a 1 GByte limitation. Otherwise, disk images may be corrupted when the 1 GByte boundary is reached. For SC0 UNIX 3.2.4, the operating system does not impose the 1 GByte limit, and this option can be turned on or off accordingly. Consequently, the >lGByte support must be turned on under the following two conditions: (1) the combined space of all the DOS partitions exceeds lGByte, or (2) >lGByte disk accesses are required to boot the operating system. To enable the > 1 GB support, turn on this option. Warning: If this option is changed, you must reformat the disk to avoid corrupting the existing file system.

Ed. The >1GB translation scheme is incompatible with IBM SCSI controllers. After formatting a DPES-13080 1.08GB drive on a BT-646S (>1GB translation enabled), I was unable to access it after then attaching the drive to a Corvette. I had to reformat the drive with the Corvette.

Note: Earlier ADF versions may have "Slot Data Width". The function of this bit was changed. The data width function is detected by the host adapter and this switch was ignored.


SDC Drivers

CONFG243.EXE - (111k) ADF files for all Storage Dimensions SCSI adapters. Buslogic drivers are the same. The Readme file.

Micro Channel RAIDCard - v2.0 (269K) all the required files to support the -002 Micro Channel RAIDCard for OS/2 and NetWare. For use under NetWare, you must also have the LANStor Plus software. When unarchiving this file, use the "-D" option to restore the directory structure.

LANStor5 - v6.10 (109k) SCSI NLM for NetWare v3.11 - supports the SDC1611/3211x under NetWare versions 3.11. Not tested or certified using NetWare v3.12 or v4.xx.

LANStor Plus - v2.50 (114k) SCSI NLM for NetWare v3.12 and v4.xx most current version of LANStor for the SDC1611/3211x, and the SDC3231WS SCSI Adapters. It includes LAPIS Plus which which is Artecon' ASPI layer (manager).

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Last update: 28 Sep 2022 - Changelog | Legal Info & Contact