• This version of the Adaptec 7800 Family Manager Set driver supports the AIC-7800 Family of Host Adapters. 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 numbers by scanning slots. Each slot is a combination of a bus number and a device number pair starting from lowest to highest numbers, and the adapters are assigned a number in the order they are found.

  Example: 
  Bus 0, device 0 assigned as adapter 0, 
  Bus 1, device 1 assigned as adapter 1, etc.
   

• On some PCI systems, users may sometimes have problems loading the driver when the host adapter board is seated in a particular slot. Moving the host adapter board to another slot may solve the problem. If the problem still persists, it may be occurring because the Adaptec 7800 Family Manager Set driver is unable to access the PCI hardware registers directly. To overcome this, users should use the /!PCIHW switch. Modify the CONFIG.SYS file to include the following line:

    For Ultra2SCSI host adapters: 
  	BASEDEV=AIC78U2.ADD /!PCIHW
    For UltraSCSI or earlier host adapters: 
  	BASEDEV=AIC7870.ADD /!PCIHW
    

• 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.
• OS2SCSI.DMD will only allocate devices when a device driver 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.
• Do NOT disable DASD manager access to target 0 if you are booting from your SCSI host adapter. This will prevent the system from booting!
• Fault Tolerance is supported in the driver. However, ABORT and SCSI BUS RESET will only work for targets that are properly behaved.
• IBM does not support installing the operating system onto magneto optical devices. Additionally, OPTICAL.SYS (OS/2 V3.0) or OPTICAL.DMD (OS/2 V4.0) allows magneto optical devices to be supported as though they were large floppy devices. LOCKDRV.FLT allows removable media such as MO's to be supported as though they were fixed hard drives.
• It is not possible to install OS/2 3.0 on drives with capacity greater than 8 GB, nor in a partition greater than 4 GB. The following is the suggestion from IBM on this problem:
  

There is a BIOS restriction that installable (startable) or bootable partitions must be contained within the first 1024 physical cylinders of the disk. FDISK does not enforce this limitation.

If you have installation or boot failures this could be the reason. Use FDISK to reduce the size of your startable or bootable partition by sufficient MBytes. One way to calculate the correct size partitions to do the following:

1. Edit your CONFIG.SYS and add the following parameter to the

   		BASEDEV=IBM1S506.ADD line as below: 
   		BASEDEV=IBM1S506.ADD /V
   		  

2. Save this change.
3. Reboot your system.
4. At initialization, record the far left hand column of number of the Geometry information under the ACT heading. Example: ACT Cyl 1027 Head 63 Sec 128 (head x sec) /2 = bootable partition must be contained within this boundary in MBytes (round down)

• OS/2 will allocate the SCSI devices as the order in CONFIG.SYS if two drivers (AIC7870.ADD and AIC78U2.ADD) are loaded.
• OS/2 will assign drive letters for SCSI devices first then IDE devices.

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 standard format for command line switches is :

 
For Ultra2SCSI host adapter:
  BASEDEV=AIC78U2.ADD [Universal Parameter][Adapter ID][Unit Parameter] {[SCSI Target ID]}  
  
For UltraSCSI or earlier host adapters:
  BASEDEV=AIC7870.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. (Refer to the Configuration 
  Examples in the "General Unit Parameters" section below for information on 
  how to use this option.)  
[Unit Parameter] - Modifies the behavior of the selected host adapter.  
[SCSI Target ID] - The targets to which the Unit Parameter will be applied. 
  This parameter may be a 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.  
/PCIHW -- Enables driver to access PCI configuration hardware registers. This 
  switch is implemented because in some PCI systems, accessing PCI configuration 
  space through PCI BIOS function calls causes problems. This switch is enabled 
  by default.  
/!PCIHW -- Disables the PCIHW switch. This parameter will cause the driver 
  to access the PCI configuration space through PCI BIOS function calls.  
 
General Unit Parameters:   
/I -- Ignore the specified adapter. This allows another driver to share the 
  adapters that the ADD would normally use.  
/DM -- Enable DASD manager support (DEFAULT). This parameter allows OS2DASD.DMD 
  to control the specified target(s) if they are identified as DASD (hard disk) 
  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).  
/TAG -- Specifies the maximum number of tagged commands for all target devices 
  on the host adapter (1-16). A value of 1 disables tagged queuing. The maximum 
  number allowed is 16. (The default is 8.)  
/UR -- Enables reporting of under runs (DEFAULT).  
/!UR -- Disables reporting of under runs.  

 Configuration Examples: 

  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.
    
The following command line will prevent OS2DASD.DMD from accessing the target 
  and still allow OS2SCSI.DMD and OS2ASPI.DMD to share access to it. 
  
BASEDEV=AIC78U2.ADD /A:0 /!DM:3  

Example 2:  
Suppose that you had a multi-disk CD-ROM as target 4 on host adapter 0 and 
  two DASD devices as targets 1 and 5 on host adapter 1. 
   
The following command line 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.  
  
BASEDEV=AIC7870.ADD /ET /A:0 /!SM:4 /A:1 /!DM:1,5  

 Special Unit Parameters: 
/TAG: -- Sets the number (1-16) of tagged commands for all target devices on 
  the host adapter. A value of one disables tagged queuing. 16 is the maximum 
  number allowed and 8 is the default value.  
/TAG:1 -- Disables tagged queuing for all target devices on a given host adapter. 
  The driver maintains a maximum of 2 non-tagged commands per target internally. 
  The driver treats all target devices as non-tagged devices, and sends only one 
  command at a time per target to the host adapter. Example:  
  
	BASEDEV=AIC78U2.ADD /A:0 /TAG:8  
	
will set the number of tagged commands for all target devices on the first 
  host adapter to 8.