IBM OS/2 DASD Documentation

FIXED IDE HARD DRIVE AND REMOVABLE MEDIA SUPPORT

October 7, 2005

OS/2 Device Driver Development

IBM Solution Technologies

Austin, TX

(c) Copyright International Business Machines Corporation, 2001, 2005. All rights Reserved.

The Latest OS2 Loader package from DDPAK should be applied to your system (or installation diskettes) prior to installing this IDEDASD package.
 * Prerequisite Support

Introduction
FixPak 35 (FP35) for Warp 3 and FixPak 6 (FP6) for Warp 4 extended support for fixed Enhanced IDE drives to sizes up to 8.4GB and added new caching HPFS and FAT file system support for removable media drives such as SCSI Syquest Syjet 1.5GB portable hard drive and the Iomega jaz 1GB and 2GB personal hard drives.

This package contains updates to the support in FP35 and FP6, extending support to fixed Enhanced IDE drives first past the 8.4GB boundary and second past the 512 Gb boundary. It also fixes some other problems, and adding additional documentation on removable media support. Beginning with FP40 and FP10 OS/2 base device drivers were separated into a Base Device Driver FixPak.

File ddk_note.txt contains programming information related to the drivers included into the IDEDASD package and can be used in addition to the DDK and SDK references.

This package also contains extensions to OS2CDROM.DMD, providing support for multi-session CDROM media.

The package also contains an updated floppy diskette driver (IBM1FLPY.ADD), which corrects a failure that occurs upon a Resume on a ThinkPad when the diskette drive is installed in the ThinkPad docking station.

Previously IDE CD-ROM (also CD-R, CD-RW, DVD) devices were handled by IBMIDECD.FLT and all other ATAPI devices (like LS-120 and ZIP drives) were handled by IBMATAPI.FLT. Now all ATAPI devices are handled by a single driver, the IBMATAPI.FLT. For backward compatibility this package provides both IBMIDECD.FLT and IBMATAPI.FLT drivers. In fact, they are the same driver and if both drivers are in config.sys only the first one in config.sys will remain loaded. It is recommended to use only IBMATAPI.FLT driver entry and remove the IBMIDECD.FLT entry from config.sys. If you do not remove the IBMIDECD.FLT entry from the config.sys, the step in section 2.4 must also be performed on the IBMIDECD.FLT entry.

For Warp Server Advanced HPFS386 support of removable media, you additionally need LAN Server SelectPack IP_8508.

These fixpaks are available from http://ps.software.ibm.com/ under the link "Downloads and News." Install the fixpaks first, carefully following the instructions with the fixpaks; then follow the directions in this README to install this package.

If you are attempting to install Warp 3 or Warp 4 for the first time on a fixed hard drive greater than 4.3GB, then: The file list for the package:
 * 1) Follow the instruction on "Updating the Installation Diskettes" in this README and use the new diskettes to install Warp.
 * 2) Install FP35 for Warp 3 or FP6 for Warp 4.
 * 3) Follow the instructions in this README to install this package.
 * dasd16.dmd
 * dasd16.sym
 * dasd32.dmd
 * dasd32.sym
 * ddk_note.txt
 * ibm1flpy.add
 * ibm1flpy.sym
 * ibm1s506.add
 * ibm1s506.sym
 * ibmatapi.flt
 * ibmatapi.sym
 * ibmidecd.flt
 * ibmidecd.sym
 * ide16.ddp
 * ide32.ddp
 * os2cdrom.dmd
 * os2cdrom.sym
 * readme.txt

Updating the Installation Diskettes
If you are attempting to install Warp on a hard drive greater than 4.3GB, or your are attempting to install Warp Server for e-business on a hard drive greater than 30GB, then the Installation diskettes must be updated.

If you are intend to install OS/2 on a hard drive greater than 512 Gb partitioned by OS/2 without OS2DASD.DMD parameter /D:n /BOOTABLE or by non-OS/2 tool, you should back up all data from the all partitions on this drive, then remove all partitions from the drive and reboot, before you start installation process. This is because OS/2 cannot currently make bootable such a drive with an acknowledged capacity larger than 512 Gb. Instead the drive must first be changed to use a smaller logical geometry which ignores part of the true capacity. This backing up process is typically laborious for a drive which is already in use; and this is why it is important to make an early and deliberate and selection of /BOOTABLE versus /FULLSIZE option for each drive with greater than 512 Gb capacity when using this version of OS2DASD.DMD on a new drive.


 * 1) Make a backup copy of your Diskette 1 (D1).
 * 2) Copy the new versions of IBM1S506.ADD, and IBMIDECD.FLT device driver files onto your D1 diskette.
 * 3) If the installation diskettes are for Warp Server for e-business, Warp Server for e-business Convenience Pak, or Warp 4 Convenience Pak, copy the DASD32.DMD file to your D1 diskette as (over the existing) OS2DASD.DMD. Otherwise copy the DASD16.DMD file to your D1 diskette as (over the existing) OS2DASD.DMD.
 * 4) Modify the CONFIG.SYS file:
 * a. Add the statement SET COPYFROMFLOPPY=1 to the CONFIG.SYS on D1.
 * b. Add the parameters /D:n /BOOTABLE to the line BASEDEV=OS2DASD.DMD in the CONFIG.SYS on D1 (/D:n refers to the intended boot drive, see section 3.10 for parameters details) for disks equal or larger than 512 Gb.
 * 1) Start the installation with the Installation Diskette and follow instructions.

NOTES:
 * a. During the installation process before rebooting your system make sure that the device driver statements are in the CONFIG.SYS file and the new versions of the IBM1S506.ADD, IBMIDECD.FLT and OS2DASD.DMD device drivers have been copied to the \OS2\BOOT directory. Use the date of the files to distinguish the newer versions.
 * b. (Follow this note instructions if your total disk capacity is larger than 512 Gb.) During installation process, you will be prompted to reinsert all diskettes and the files will be copied from the diskettes to the hard drive. After coping and before rebooting (you will see the message "Remove the diskette and press Enter to restart the workstation and continue the installation") you must exit to command prompt (using F3) and remove duplicate line containing "BASEDEV=OS2DASD.DMD /D:n /BOOTABLE" from ending of the CONFIG.SYS. There should remain the line "BASEDEV=OS2DASD.DMD" in the middle of the CONFIG.SYS.

Updating a Previous Installed Warp System

 * 1) (Optional) Save the existing (old) level of drivers in your system.
 * a. Change Directory to the \os2\boot directory on your boot drive.
 * b. Rename the drivers (for example, where the boot drive is C:). The IBMATAPI.FLT driver may not have been previously installed.
 * [C:\os2\boot] rename IBM1S506.ADD IBM1S506.ORG [C:\os2\boot] rename IBM1FLPY.ADD  IBM1FLPY.ORG [C:\os2\boot] rename IBMIDECD.FLT  IBMIDECD.ORG [C:\os2\boot] rename IBMATAPI.FLT  IBMATAPI.ORG [C:\os2\boot] rename OS2CDROM.DMD  OS2CDROM.ORG [C:\os2\boot] rename OS2DASD.DMD   OS2DASD.ORG
 * 1) Open an OS/2 Window and enter the SYSLEVEL X: (where X: is your boot drive). Look for the entry x:\OS2\INSTALL\SYSLEVEL.OS2 and see which version of OS/2 you have installed; for example "Version 4.00" or "Version 4.50".
 * 2) Device Driver Install
 * 3) * (Warp 3, Warp Server) Open the Device Driver Install program in the OS/2 System Folder/System Setup Folder.
 * 4) * (Warp 4, Warp Server for e-business) Open the Device Driver Install program in the OS/2 System/System Setup/Install-Remove Folder.
 * 5) Point the Device Driver Install file dialogue to the directory where you have placed the new files in this package.
 * If your version of OS/2 is 4.00 or earlier, select the driver named IBM IDE AND REMOVABLE MEDIA SUPPORT (V4.00).
 * If your version of OS/2 is 4.50 or later, select the driver named IBM IDE AND REMOVABLE MEDIA SUPPORT (V4.50).
 * Click on INSTALL.
 * 1) Reboot the system.

Recommended Parameters for IBM1S506.ADD
For normal functioning of Extended WarmSwap support IBM1S506.ADD must be configured as follows: Examples:
 * 1) Edit config.sys
 * 2) Find the line with IBM1S506.ADD: "BASEDEV=IBM1S506.ADD"
 * 3) Add (if they aren't already there) the following parameters: "BASEDEV=IBM1S506.ADD /A:n /U:m /ATAPI /FORCE" where n is adapter number and m is unit number.
 * 4) Save config.sys
 * 5) Reboot
 * "BASEDEV=IBM1S506.ADD /A:1 /U:0 /ATAPI /FORCE" enables swapping on ThinkPad Ultrabay.
 * "BASEDEV=IBM1S506.ADD /A:2 /U:0 /ATAPI /FORCE" enables swapping on DockingStation Ultrabay.

See section 3.8 for description of these parameters.

Recommended Parameters for IBMATAPI.FLT and IBMIDECD.FLT
For normal functioning of WarmSwap support IBMATAPI.FLT must be configured as follows:
 * 1) Edit config.sys
 * 2) Delete line with IBMIDECD.FLT (see note below): "BASEDEV=IBMIDECD.FLT"
 * 3) Find the line with IBMATAPI.FLT: "BASEDEV=IBMATAPI.FLT"
 * 4) Add (if they aren't already there) the following parameters: "BASEDEV=IBMATAPI.FLT /A:n /U:m /TYPES:CLZ" where n is adapter number and m is unit number. They must be the same as for IBM1S506.ADD (see sect. 2.3 for details)
 * 5) Save config.sys
 * 6) Reboot

Examples:
 * "BASEDEV=IBMATAPI.FLT /A:1 /U:0 /TYPES:CLZ" enables swapping of LS-120, LS-240, ZIP, CD type devices in ThinkPad Ultrabay.
 * "BASEDEV=IBMATAPI.FLT /A:2 /U:0 /TYPES:CLZ" enables swapping of LS-120, LS-240, ZIP, CD type devices in DockingStation Ultrabay.

See section 4.5 for description of these parameters.

Note: If you do not remove the IBMIDECD.FLT entry from config.sys, then step 4 must also be performed on this entry.

Recommended parameters for IBM1FLOPPY.ADD
To enable external and ultrabay floppy drive functioning with WarmSwap IBM1FLOPPY.ADD must be configured as follows:
 * 1) Edit config.sys
 * 2) Find the line with IBM1FLPY.ADD: "BASEDEV=IBM1FLPY.ADD"
 * 3) Add (if they aren't already there) the following parameters: "BASEDEV=IBM1FLPY.ADD /A:n /FORCE:2 /U:m /F:1.44MB /U:m /F:1.44MB" where n is adapter number and m is unit number.
 * 4) Save config.sys
 * 5) Reboot

Example: "BASEDEV=IBM1FLPY.ADD /A:0 /FORCE:2 /U:0 /F:1.44MB /U:1 /F:1.44MB"

System Hang or Hard Drive Hesitation
The problem is the IDE chip sets on certain planars indicate that they support Bus mastering but actually have a defect that prevents them from working correctly. The driver detects bus mastering support, enables busmastering and attempts to use it. Some symptoms are: This is a known problem with ThinkPad models 760E/ED/ELD/EL. However the chip set can, and does, show up on planars of other manufacturers. To correct:
 * System will not boot with IBM1S506.ADD.
 * CHKDSK command does not work properly.
 * Hard drive stops or hesitates for minutes at a time.
 * 1) Edit the CONFIG.SYS file on Diskette 1 or the boot drive.
 * 2) Disable busmastering by adding the parameter /!BM to the driver; for example: BASEDEV=IBM1S506.ADD /A:0 /!BM /A:1 /!BM
 * 3) Save the changes and reboot.

Cannot Mark a Partition Installable
There is a BIOS restriction for most older (typically pre-2001 manufacture) computers that installable (startable) or bootable partitions must be contained within the first 1024 logical cylinders of the disk. This is true for both EIDE and SCSI hard disk drives. If FDISK fails to allow a partition to be marked installable, the partition is either above 1024 cylinders or the partition spans the first 1024 logical cylinders of the disk. Use FDISK to reduce the size of the startable or bootable partition by sufficient MBytes. One way to calculate the correct partition size is to do the following: OS2:log C      1027 H        63 S       128 4. Calculate the 1024 cylinder size in MBytes as ( H x S ) / 2. (round down).
 * 1) Edit your CONFIG.SYS and add the parameter /W or /V to the BASEDEV=IBM1S506.ADD statement.
 * 2) Save this change and reboot the system.
 * 3) At initialization, record the far left hand column of numbers of the geometry information under the OS2:log heading; for example, where C=cylinder, H=head, and S=sector:
 * All bootable partitions must be contained within this size. In this example the bootable partition must be contained in the first 4032 MBbytes of the disk and cannot exceed a single partition size of 4032 MBytes within this area. No bootable partition may extend beyond the first 4032 MBytes.

5. Use FDISK to resize the partitions and reboot.

IPE on Boot, "Trap D"
If you experience a Trap D on boot when using the /FORCE parameter on IBM1S506.ADD, and you have the NetFinity client installed, REMark out the BASEDEV=NFDASD.FLT statement in CONFIG.SYS.

Inconsistencies in Total Disk Space
This version of IBM1S506.ADD allows the detection and correct reporting of some additional free space on certain drives. This "free space" is real and now can be accessed, either by creating a new partition or using a program such as PartitionMagic to add the free space to an existing partition. This will not cause any corruption or inaccessibility to the data currently on the disk.

Application Install Fails with "Not Enough Space"
FAT partitions under OS/2 are limited to a 2.1GB maximum size. HPFS partitions are limited to a 64GB maximum size. However there is the magic number, 2,147,483,647 (2.1GB). This 2.1GB value is the maximum number that will fit into a signed 32-bit integer. Some application software installation programs query OS/2 about the available remaining space on the partition and save the result into a signed 32-bit integer. If more than 2.1GB is available there is an overflow, it appears no space is available, and the installation program refuses to continue. Two solutions are:
 * Partition the remaining space into maximum 2GB partitions.
 * Retain the large partition, but before trying to install software create a large temporary file that reduces available space to less than 2.1GB. After installation of the application delete the temporary file.

Performance Problems with Two Devices on a Single Channel
With certain planars, two devices attached to the same IDE channel will exhibit performance problems when one device is a slow non-DMA device like a CDROM or removable drive and the other device is a faster disk drive. To alleviate this problem move the slow device to the other channel, where it is the only device or is paired with a similar slow device.

If moving the device is not possible, then you can disable busmastering for that channel, by specifying parameters on the driver IBM1S506.ADD in CONFIG.SYS. For example, if you wanted to disable bus mastering for the secondary controller, you would add the parameters "/A:1 /!BM" to the IBM1S506.ADD line in CONFIG.SYS.

Install Diskettes or Utility Diskettes Hang on Boot (APAR JR12065)
Diskette 1 of the Install or Utility diskette sets may appear to hang on boot, waiting for a removable media device to respond. To avoid:
 * 1) Edit the CONFIG.SYS on Diskette 1 of the set
 * 2) REMark out the basedev=ibmint13.i13 statement and save the file.
 * 3) Reboot

Additional Parameters for IDE Device Driver
Example: BASEDEV=IBM1S506.ADD /A:0 /U:0 /!SAL

Very Large (128/137 Gb limit) Hard Drives Considerations (48 bit LBA)
Legacy LBA (also know as 28 bit LBA) maximum drive capacity is limited to 137 GB (268,435,455 sectors by 512 bytes each). The 48 Bit LBA support was introduced to break this barrier and provide support for hard disk with capacities larger than 137 GB.

This version of the IBM1S506.ADD driver has the 48 bit LBA support and the driver will automaticaly detect drives with the capability of 48 bit LBA. This 48 bit LBA support will allow the use of hard disk drives with up to 2 TB (Terabytes) (1 TB = 1024 GB) capacity.

In spite of the original removal of the 28 bit restriction, before the addition of 512 Gb logical geometry support, the OS2DASD.DMD driver also had a geometry imposed limitation which limited the maximum physical hard disk capacity which OS/2 could support to 512 Gb.

To maintain backward compatibility a new config.sys parameter,"/!BIGLBA", is introduced. If "/!BIGLBA" is specify in config.sys, this parameter for the specfic drive will disable 48 bit LBA support and will revert to legacy 28 bit LBA and usable drive capacity will be limited to 137 GB (268,435,455 sectors by 512 bytes each). If the drive is partitioned when using this switch, then it will be compatible when connected to a system without 48 bit LBA support. See section 3.8 for the "/!BIGLBA" parameter syntax.

Very Large (512 Gb limit) Hard Drive Considerations
The previous version of OS2DASD.DMD had a 512 Gb geometry limitation which allowed only part (remainder of the total drive capacity divided by the 512 Gb) of the hard drive to be accessible for the system.

The current version of OS2DASD.DMD removes this limit and allows total capacity of the hard drive up to 2 Tb. This support has the following options:
 * 1) If the drive is used as a boot drive, only first 512 Gb of the drive space will be accessable to the system.
 * 2) If drive is used only as a data storage drive the total capacity (up to 2 Tb) of drive will be accessable to the system. The two new parameters are available to select these options:
 * 3) * /BOOTABLE - applied to the unpartitioned large drive (during the bootup prior to the first partitioning of the drive) and makes drive bootable, but limiting its available capacity to 512 Gb.
 * 4) * /FULLSIZE - applied to the unpartitioned large drive (during the bootup prior to the first partitioning of the drive) and allow use of the total capacity of the drive (up to 2 Tb), but prevents the drive from being made bootable.

The parameters have the following usage syntax: BASEDEV=OS2DASD.DMD [/D:n] [/BOOTABLE | /FULLSIZE] where /D:n denotes the number of the drive (/D:0 is drive 0, etc.). Parameter /BOOTABLE or /FULLSIZE following /D:n is applied to drive n. If for some drive value n (n>0) the /D:n parameter is omitted the following parameter (/BOOTABLE or /FULLSIZE) is applied to the first drive (default /D:0). If parameter /BOOTABLE or /FULLSIZE for some drive is omitted, /FULLSIZE is applied for this drive by default.

If drive is larger than 512 Gb,  then LVMUPDT package must  be installed in addition to the IDEDASD package to access the full drive capacity (/FULLSIZE option). If drive is not larger than 512 Gb that  IDEDASD package is enough to access the full drive capacity, but LVMUPDT package  may be installed in addition.

Format Error While Installing from Updated Diskettes
If you get a format error message while installing OS/2 from updated diskettes, check whether you have the following line in the CONFIG.SYS: BASEDEV=OS2DASD.DMD /D:n /BOOTABLE If instead you have the line: BASEDEV=OS2DASD.DMD

without the parameter /BOOTABLE for the intended boot drive /D:n, then you will need to:
 * 1) Stop your current installation of OS/2
 * 2) Backup any data which you intend to preserve from the all the partitions on the intended boot drive /D:n which you intend to preserve
 * 3) Remove all the partitions on the intended boot drive /D:n
 * 4) Reboot
 * 5) Modify your CONFIG.SYS file on the D1 diskette to add /D:n /BOOTABLE, if it is not there already
 * 6) Restart the installation process of OS/2 from the beginning
 * 7) Restore backed up data to new partitions using the new logical geometry

Since all this backing up and restoring is typically quite inconvenient, it is highly advisable to decide quite deliberately whether or not you intend to use your large drive as a boot drive before you partition it and modify your CONFIG.SYS file on your D1 diskette accordingly, as previously documented.

Installation Process Hangs after Rebooting When Installing from Updated Diskettes
If the installation process hangs after rebooting when installing from updated diskettes, then see section 3.10.1 for possible reason and recovery instructions.

Removable Media Support
Removable media devices attach to the system by a variety of interfaces. Removable media devices are supported in one of two ways.
 * LARGE FLOPPY:The LS-120 / LS-240 drive.
 * PARTITIONED:All other magnetic removable media devices. This media appears as a removable hard drive.

Partitioned Removable Media
Features of the partitioned removable media support are:
 * Ability to partition removable media into multiple partitions
 * Ability to format with either HPFS or FAT
 * Ability to exploit caching performance
 * Ability to use HPFS long file names
 * Drag/drop capability through the Workplace drive icon
 * Operating system protection to safely eject media through software eject utility
 * Assignment of drive letters to end of disk drive lettering chain to prevent floating drive letters
 * Ability to predetermine a fixed number of drive letters for multiple partitions for removable media

Using Protected Media
There are some restrictions on the use of these devices. These restrictions deal with vendor-provided protection routines that either read/write or password protect the media.

You are unable to read or write HPFS formatted media that has been read, write or password protected by a vendor supplied protection utility. For all read and write protected media, remove the vendor protection prior to trying to read or write to the media. For instance, if you do not remove the protection, you will get the following failures: Once the vendor supplied protection is removed, then these errors will no longer occur.
 * If you issue a DIR command to write or password protected media, you will receive a "Drive improperly stopped" error message.
 * If you try to FORMAT a write or password protected media, you will receive numerous error messages after a few minutes.
 * If you try to use desktop operations like drag/drop folders/files, you will receive numerous error messages.

Assignment of Drive Letters
New Algorithm: no filters assumed

Primary from fixed disk 1 Primary from fixed disk 2

Primary from fixed disk n    Extended from fixed disk 1 Extended from fixed disk 2

Extended from fixed disk n    Primary from removable disk 1 Extended(s) from removable disk 1 Primary from removable disk 2 Extended(s) from removable disk 2

Primary from removable disk n    Extended(s) from removable disk n Lack of a primary partition (or Extended Partition only) is allowed. If no media is present at boot, a single logical drive is reported. Note that some drives, Syquest EZ135A for example, do NOT report correctly when no media is present and will not be seen at all. If media with multiple partitions is present at boot, then all partitions will be assigned drive letters.

Configuring Partition Support (OS2DASD)
BASEDEV=OS2DASD.DMD [/LF] [/MP:(disk,count)[,(disk,count)]] If the /MP parameter is used, then: If the /MP option is not used, the rules for determining the number of drive letters reserved for a partitioned removable media device are as follows:
 * If there is no media in the drive at boot time, or the media in the drive has no valid partitions, then one drive letter is reserved for the device.
 * If there is media in the drive at boot time and the media has valid partitions which are eligible for drive letters, the number of drive letters is equal to the number of eligible partitions on the media. Media which is formatted in floppy mode is treated as a single partition and allocated a single drive letter.

Ejecting the Media
OS/2 prevents the media from being ejected during data transfers or while there are pending file transactions. The hardware manual eject button is disabled during these times. The eject button will be enabled when the media can be safely ejected.

There is a new OS/2 utility, EJECT.EXE, that provides a command line method for ejecting the media. The Workplace Drive Icon now supports the software eject option for these drives as well. For example, the command EJECT J:, where J: is the logical drive letter of one of the partitions on the media will cause the media to be ejected.

In order for this command to succeed there must be no open files on any of the partitions on the media, nor any open search operations. Removable media that is shared on a server cannot be ejected because of open file handles. If it is necessary to remove the media without rebooting you may issue the command CHKDSK J: /F, where J: is the logical drive letter of one of the partitions on the media. This will free the media and a subsequent EJECT J: command will cause the media to be ejected.

4Limitations of Partitioned Removable Media Support
must be updated to test the fixed/removable flag in order to account for partitioned removable devices. Such applications that have not been updated treat the removable devices as fixed and the results are unpredictable whenever media is not present.
 * Applications that manipulate partitioned devices, such as file managers,
 * Due to the variability of hardware adapter support, installing to or booting from partitioned removable media is not supported.
 * Optical drive support is unchanged. Partitioned removable media and HPFS do not support optical drives. You should continue to use OPTICAL.DMD and OS2SCSI.DMD.
 * The following devices were tested during the development of the Partitioned Removable Media Support. Similar devices should operate correctly, as should other removable media devices that are made available with a supporting ADD device driver.
 * Iomega SCSI jaz 1GB and 2GB personal hard drives
 * Iomega Zip ATA 100MB drives (supported only as single partition media).
 * Iomega Zip ATAPI 100 MB drives
 * Iomega Zip ATAPI 250 MB drives
 * Syquest SCSI Syjet 1.5GB portable hard drives
 * Syquest IDE Syjet 1.5GB portable hard drives
 * Syquest SparQ IDE portable hard drives

Large Floppy Removable Media (LS-120 / LS-240)
The LS-120 drive supports 120-MB diskettes and is compatible with 3.5 inch 1.44-MB standard diskettes, with improved performance. The LS-240 drive supports 240-MB diskettes, 120-MB diskettes and is also is compatible with 1.44-MB standard diskettes.

Limitations of LS-120 / LS-240 Support

 * If you have an LS-120 drive as drive B, then you must not format it from an OS/2 windowed or full screen session where the current drive is drive A or drive B. The current drive for an OS/2 windowed or full screen session is given as part of the command prompt. For example, if the command prompt in an OS/2 windowed or full screen session is [C:\], then drive C is the current drive.
 * If an LS-120 drive is installed in a ThinkPad docking station and a CD-ROM or DVD drive is in the system UltraBay, you may get an error message "A program in this session encountered a problem and cannot continue." when a DOS window is opened. In this case edit the config.sys file and move the statement BASEDEV=IBMIDECD.FLT so that it appears before the statement BASEDEV=IBMATAPI.FLT in the file.
 * The following devices were tested during the development of the Large Floppy Removable Media Support. Similar devices should operate correctly.
 * Imation LS-120
 * SuperDisk LS-120
 * SuperDisk LS-240

CD-ROM Device Manager (OS2CDROM.DMD)
The CD-ROM Device Manager (OS2CDROM.DMD) has several additional features. These features are described in file ddk_note.txt. This file is included into this IDEDASD package.

CD-RW Media Support in IBMIDECD.FLT and IBMATAPI.FLT
IBMIDECD.FLT and IBMATAPI.FLT now supports IDE CD-Writers for reading and writing.

Supported Chipset Table
The OS/2 IDE Controller Adapter Device Driver (IBM1S506.ADD) supports the following PCI IDE Controllers

Known Restrictions and Limitations
This section covers some restrictions and/or limitation for the IBM1S506.ADD driver. These restrictions are mainly due to hardware problems.

DMA for ATAPI devices is disabled by default. The exception to this is ATAPI devices on Intel I82801AA chipset and later Intel chipsets (including all SATA controllers). DMA for the ATAPI device can be enabled manualy by using the "/BM" parameter. (To enable it see sec. 3.8) Example: "/A:1 /U:0 /BM" enables DMA for the Master device attached to the secondary IDE channel.

If a device is UDMA capable, using "/BM" parameter is recommended only if the IDE 80 pin flat ribbon cable is used (instead of standard 40 pin flat cable).

The IBM xSeries 226 with the optional ServeRaid 6i adapter will not work with the IDE (Parallel and/or Serial ATA) hard drives enabled. When trying to use the ServeRaid adapter with the IDE hard drives enabled simultaneously, a Trap D system error will occur during system boot. This restriction applies to hard drives (HDD) only and does not apply to ATAPI devices (CD, DVD, etc). To avoid this system error either disable the HDD attached IDE controllers, remove the IDE HDD drives from the system or remove the ServerRaid adapter from the system.

5.2.1 Intel Chipsets Limitations

 * for the 82801AA, 82801BA and 82801BA Mobile chipsets where there are 2 devices on a channel, the fastest UDMA mode will be limited to UDMA 2.
 * on some systems with 82801DB and later chipsets there is problems with proper 80 pin cable detection. To avoid problems with cable detection use only 80 pin IDE cables. The 80 pin cable are a requirement for devices to operate in UDMA mode and are usually installed in the system when the drive and system support UDMA. If you use 40 pin cable on primary or secondary channel, specify the parameter "/UDMA:2" in CONFIG.SYS for that channel. Usage of this parameter is described above (see sec. 3.8). Examples: use "/A:0 /UDMA:2" if you have a 40 pin cable on the primary channel use "/A:1 /UDMA:2" if you have a 40 pin cable on the secondary channel use "/A:0 /UDMA:2 /A:1 /UDMA:2" if you have a 40 pin cable on both channels
 * for 82801 series chipsets (including all SATA controllers) DMA is enabled for ATAPI devices by default. It can be disabled using "/!BM" parameter (see sec. 3.8). Example: "/A:1 /U:0 /!BM" disables DMA for Slave device attached to secondary IDE channel. "/A:1 /U:1 /!BM" disables DMA for Slave device attached to secondary IDE channel.

VIA Chipsets Restrictions
The IBM1S506.ADD driver has the following limitations for the VIA IDE controllers listed above: At Adobe Systems Technical Director: Tom Malloy Project Manager: Ming Lau Senior Developer: Jon von Zelowitz PC Fonts Product Manager: Peter Koester At IBM Hursley Technical Director: Ian McCallion Project Manager: Colin Powell Developers: Robin Speed Andrew Skates Integration & Testing: David Kerrchannel. Usage of this parameter is described above (see sec. 3.8).
 * all of the VIA chipsets have a problem with 80 pin cable detection. To avoid problems with cable detection use only 80 pin IDE cables. The 80 pin cable are a requirement for devices to operate in UDMA mode and are usually installed in the system when the drive and system support UDMA. If you use 40 pin cable on primary or secondary channel, specify the parameter "/UDMA:2" in CONFIG.SYS for that OS/2 ATM Development Team

Examples:
 * use "/A:0 /UDMA:2" if you have a 40 pin cable on the primary channel
 * use "/A:1 /UDMA:2" if you have a 40 pin cable on the secondary channel
 * use "/A:0 /UDMA:2 /A:1 /UDMA:2" if you have a 40 pin cable on both channels


 * any VIA chipset, which is not listed above, but has the same PCI Device ID, will be detected as a VIA586B and UDMA performance mode will be limited to UDMA 2 for any device that can operate above UDMA Mode 2.

SiS Chipset Limitations
For SiS IDE controllers listed above the following restrictions applies:
 * If there is a UDMA device on the SiS Secondary channel and an 80 pin ribbon cable is not detected, then the driver will limited the mode to PIO for this channel.
 * Some systems with SiS chipsets may be unable to boot from a FAT partition if the Hard Drive capacity is larger than 32GB. In this case, you can either boot from an HPFS partition or change your BIOS settings to disable "Block mode" for this drive in the system's setup.

Chipset Extended Detection Algorithm for Intel Chipsets
The IBM1S506.ADD driver can automatically detect all PCI IDE chipsets described in section 5.1 and enables the highest possible DMA/UDMA modes for all drives. Because Intel's chipsets provide good backward compatibility it is possible to detect a newer chipset and use it as the latest known one. To use this feature, this support must be enabled by the user with a config.sys parameter "/CDA". If this parameter is specified, then Extended Detection Algorithm will be enabled and newer Intel chipset can be detected as the latest chipset described in the supported chipset table (see section 5.1) and higher possible DMA/UDMA modes can be properly detected and enabled for all drives attached to that chipset.

If a system hang or trap occurs when this parameter is used, then it should be removed from config.sys and legacy detection mode should be used for that chipset.

Serial ATA for Intel Chipsets Considerations
The IBM1S506.ADD driver automatically detects Intel Serial ATA and Parallel ATA controllers described in section 5.1 and enables the highest possible DMA/UDMA modes for all drives. For PATA devices (know also as standard IDE devices or ATA devices) the maximum transfer rate for Intel IDE controllers is ATA100. For SATA devices this is SATA150. For SATA devices parameters /UDMA:n and /!UDMA (see section 3.8 for details) have no effect. SATA devices in DMA mode will always operate in the maximum possible transfer rate.

Intel 82801FR and 82801GR support in IBM1S506.ADD
IBM1S506.ADD driver supports "R" versions of chipsets (82801FR and 82801GR) only in legacy mode if the SATA controller is configured to operate as an IDE controller (in legacy mode) by the system BIOS. If the ICH6R or ICH7R SATA controller is configured to operate as RAID or if AHCI mode is enabled, then the IBM1S506 driver will not detect the SATA controller. The IBM1S506 driver does not support any RAID functionality and the IBM1S506 does not support SATA controllers in AHCI mode.

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