Here is the latest release driver for Adaptec 1540 family host adapters
and OS/2 2.X. 

 AHA154X.ADD    19591   5-02-94  3:47pm

Command line switches for Adaptec drivers and OS/2 2.X

OS/2 adapter device drivers (.ADD files) are normally installed automatically 
and require no further information from the user. However, in certain situations 
the user may wish to modify the behavior of the driver to meet their specific 
needs. 

***** IMPORTANT *****
Please proceed cautiously with the following information. If you have purchased
software which requires you to use switches, it should include instructions
on how to use them. Most software requires no switches and you do not need to
concern yourself with the information about switch settings.

The following examples will all use the driver for the Adaptec 1542 family, but the 
driver for any other Adaptec host adapter can be used instead.

The standard format for command line switches is :
BASEDEV=AHA154X.ADD  [Universal Parameter] 
		     [Adapter ID] [Unit Parameter] {: [SCSI Target ID]}

[Universal Parameter] - An option that applies to all adapters controlled by 
			the driver.

[Adapter ID] - /A:n, where n is the number (zero relative) of the adapter installed 
	       in the
	       system. The adapter ID is determined when the driver is loaded 
	       based on the order that adapters are found in the system. 
	       Please refer to the section on each host adapter to determine 
	       the scanning order.

[Unit Parameter] - The modification being made to the behavior of the selected 
		   host adapter.

[SCSI Target ID] - The targets to which the Unit Parameter will be applied. 
		   This parameter may be and single ID (d) or list of IDs 
		   (d,d,d).

Universal Parameters

	/ET - Allow embedded targets.  This parameter indicates that the ADD 
	should assume that all targets have more than one logical unit (LUN) 
	defined.

	/!ET - Do not allow embedded targets (DEFAULT). This parameter 
	indicates that the ADD should assume that all targets have only one 
	logical unit (LUN) defined.

	/V - Load driver verbosely. This parameter will display the driver 
	name as well as the version number and Adaptec copyright if the driver 
	loads successfully. Information on all targets found in the system 
	will also be displayed. This switch is only valid in drivers dated 
	11/24/92 and later.

General Unit Parameters


	/DM - Enable DASD manager support (DEFAULT). This parameter allows 
	OS2DASD.DMD to control the specified target(s) if they are identified as DASD 
	devices.

	/!DM - Disable DASD manager support. This parameter prevents 
	OS2DASD.DMD from controlling the specified target(s).

	/SM - Enable SCSI manager support (DEFAULT). This parameter allows 
	OS2SCSI.DMD to control the specified target(s) if they are identified as NON-
	DASD SCSI devices. All SCSI hard drives will be controlled by OS2DASD.DMD.

	/!SM - Disable SCSI manager support. This parameter prevents 
	OS2SCSI.DMD from controlling the specified target(s).

	Example 1
	Suppose that you had a removable hard drive as target 3 and you wanted 
	to control the hard drive with an ASPI application and driver. 
	Normally OS2DASD will allocate this device, treat it as a large 
	floppy and prevent you from sending any SCSI commands via ASPI. 

	BASEDEV=AHA154X.ADD /A:0 /!DM:3 will prevent OS2DASD.DMD from 
	accessing the target and still allow OS2SCSI.DMD and OS2ASPI.DMD to 
	share access to it.

	Example 2
	Suppose that you had a CD-ROM as target 4 on host adapter 0 and 
	two DASD devices as targets 1 and 5 on host adapter 1.

	BASEDEV=AHA154X.ADD /ET /A:0 /!SM:4 /A:1 /!DM:1,5 will prevent 
	OS2SCSI.DMD from accessing the CD-ROM and prevent OS2DASD.DMD from 
	controlling the DASD devices. The driver will also search for multiple
	LUNs on all host adapters.

	Important Tips
	1)There are no switches for controlling OS2ASPI.DMD directly. IBM did      
	not define them in their specification and we cannot be sure that other host 
	adapters will have the same switches.

	2) OS2SCSI.DMD will only allocate devices when a device drivers 
	requests it, but this will prevent OS2ASPI from accessing it. There is 
	nothing in the ASPI specification regarding device allocation so 
	OS2ASPI must rely on other managers to fairly share targets. This 
	should only be a problem if you have two drivers that use different 
	managers and you want them both to access the same target at the same 
	time.

	3) Do NOT disable DASD manaager access to target 0 if you are booting
	from your SCSI host adapter. This will prevent the system from booting.
	
Driver Specific Information

AHA152X.ADD
This driver can support two host adapters and searches for them at ports 340H 
and 140H; boards are assigned adapter numbers in the order they are found.

      Special Unit Parameters

	/D - Allow targets to disconnect from the SCSI bus (DEFAULT).
	/!D - Prevent targets from disconnecting from the SCSI bus.

	/H:x - Specifies the host adapter SCSI ID. A number from 0-7 replaces 
	x. The default ID is 7. If you specify an invalid number, the default 
	is used.

*** IMPORTANT
	Synchronous negotiation is enabled by default.

	/Y - Enable parity checking on the SCSI bus (DEFAULT).
	/!Y - Disable parity checking on the SCSI bus.

AHA154X.ADD
This driver can support four host adapters, distributed among six possible 
port addresses. The port addresses are scanned in the order 330H, 334H,
230H, 234H, 130H, 134H; boards are assigned adapter numbers in the order 
they are found.

	Special Unit Parameters (09/19/92 and later )

	/BON:t - allows the bus-on time to be set to a value between 2 and 15 
	microseconds. The default value for OS/2 2.0 is 7 microseconds and 
	this value should be used for most systems. 

	/BOFF:t - This command sets the time that host adapter will spend off
	the bus during a data transfer. The default is 4 microseconds and it is
	adjustable from 1 to 64 microseconds.

	/D - Allow targets to disconnect from the SCSI bus (DEFAULT).
	/!D - Prevent targets from disconnecting from the SCSI bus.
	*** This command is not supported on boards earlier than revision B.


AHA164X.ADD
This driver can support host adapters installed in any 16-bit MCA slot. The 
slots are scanned from lowest to highest and boards are assigned adapter 
numbers in the order they are found. The slots are scanned twice, the first 
scan will find all boards with their BIOS enabled and the second will find 
those with their BIOS disabled.

AHA174X.ADD
This driver can support host adapters installed in any EISA slot. Adapter 
numbers are first assigned to boards with their BIOS enabled; the numbers are 
assigned from lowest BIOS address to highest address. Any remaining boards are 
assigned adapter numbers by scanning the slots from lowest to highest and 
boards are assigned adapter numbers in the order they are found.
