No Drive Letter When Using PC-Card Type III Slot

• Microsoft Windows NT Workstation version 3.51
• Microsoft Windows NT Server version 3.51

SYMPTOMS

When you have a computer with a PC Card type III slot and you start Windows NT 3.51, there may not be a new drive letter and the hard disk does not appear in Disk Manager.

When you start the PC Card tool that comes with the Windows NT Resource Kit and try to view the configuration of the PC Card, the following pop-up dialog box appears:

   PCMCIA.SYS returned invalid configuration information.

CAUSE

The PCMCIA driver in Windows NT has no information on how to deal with a tertiary IDE channel and thus does not configure it for use by a driver.

RESOLUTION

Upgrade to Windows NT 4.0.

-or-

Obtain Service Pack 5 for Windows NT 3.51 (referenced below under STATUS) and then take the following steps:

After you apply Service Pack 5, PCMCIA.SYS reports the device correctly and you can configure the settings for the use of ATDISK manually. Now that you have replaced the driver you should be able to see the configuration of the PC Card hard disk after reboot. It should have an I/O base of 0x160 and an available interrupt.

WARNING: Using Registry Editor can cause serious, system-wide errors that may require you to reinstall Windows NT. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

1. Open the Registry Editor (Regedt32.exe).

2. Go to the following path:

         HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Atdisk
   

3. On the Edit menu, click Add Key to create the following entry:

         Key Name: PARAMETERS
         Class: <blank>
   

4. Open the PARAMETERS key that you created in Step 3.

5. On the Edit menu, click Add Key to create the following entries

         Key Name: X
         Class: <blank>
   

   where X is the number of the additional drive, such as 2 for the third drive. For each additional drive, increment the Key Name by 1. Generally, you MUST specify the starting parameter as 2 or higher. This is so that you do not interfere with the primary or secondary controller that most BIOSes support.

6. Select the key that you created in step 5; it should be named 2. Using the Add Value option on the Edit menu, add the following three values:

         Value Name   BaseAddress
         Data Type    REG_DWORD
         String       0x160
   
         Value Name   DriveControl
         Data Type    REG_DWORD
         String       0x16E
   
         Value Name   Interrupt
         Data Type    REG_DWORD
         String       <interrupt from the PCMCIA applet>
   
   

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.51. This problem has been corrected in the latest Microsoft Windows NT U.S. Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

MORE INFORMATION

Windows NT 4.0 correctly configures a PC Card hard disk as a third IDE channel. Once you update your computer to Windows NT 4.0, you should remove the registry keys created in the steps above.