Adaptec drivers

If you are having problems with the current ADD used by your host adapter
and OS/2 2.0. You may want to try the newer version included here. Please
keep a copy of the older version in case you want to return to it later.

The 1540A was NOT properly supported by previous versions of the AHA154x.ADD.
Please try the new version if you have an A board. You may want to remove
the line for IBMINT13.I13 from your CONFIG.SYS to verify that the ADD is
being loaded correctly. If you then get a message about COUNTRY.SYS not found
it is very likely that the ADD is NOT being loaded.


Command line switches for Adaptec drivers and OS/2 2.0

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. 

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

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

[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).

General Unit 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.

	/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).

	Please note that there are no switches for controlling OS2ASPI.DMD 
        directly. This is because it was not defined in IBM's specification 
        and we cannot be sure that other host adapters will have the same 
        switches. Since OS2ASPI.DMD shares devices (unlike OS2DASD.DMD) this 
        should not be much of an inconvenience.

	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 /A:0 /!SM:4 /A:1 /ET /!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 host adapter 1.

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.

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 (07/31/92 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. 



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.

AHA174X.ADD
This driver can support host adapters installed in any EISA slot. The slots 
are scanned from lowest to highest and boards are assigned adapter numbers 
in the order they are found.


