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Q75488: Floppy Disk Drive Problems in 386 Enhanced Mode

Article: Q75488
Product(s): Microsoft Windows 95.x Retail Product
Version(s): WINDOWS:3.0,3.0a,3.1,3.11
Operating System(s): 
Keyword(s): 
Last Modified: 08-JAN-2000

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows versions 3.0, 3.0a, 3.1, 3.11 
-------------------------------------------------------------------------------

SYMPTOMS
========


If you are experiencing errors reading, writing, or formatting floppy disk drives
while running Windows in 386 enhanced mode, follow the steps listed below to
troubleshoot and resolve the problem.

WORKAROUND
==========

1. Exit Windows.

2. To determine whether your system is reading the floppy disk directory, insert
  a disk in drive A, and type the following at the MS-DOS command prompt:

  " dir a: " (without the quotation marks)

  NOTE: If you remove the disk from drive A and type "dir a:" (without the
  quotation marks) and the directory lists again, it is an indication of an
  improper CMOS version or incorrect hardware setup (for example, a 3.5-inch
  drive on a jumper for an XT computer).

3. To determine whether your system writes to the floppy disk drive, type the
  following at the MS-DOS command prompt

  " copy <filename> a: " (without the quotation marks)

  where <filename> is any valid file on your hard disk.

  If the commands in steps 2 and 3 do not work, the problem is at the MS-DOS
  level.

4. Restart your computer using the minimum information in your AUTOEXEC.BAT file
  and CONFIG.SYS file that your computer needs to start up. For more
  information about how to do this, query on the following words in the
  Microsoft Knowledge Base:

  " troubleshooting and autoexec.bat and config.sys and files " (without the
  quotation marks)

  NOTE: Anti-Virus software commonly causes this problem.

5. Does the floppy disk drive read problem go away when you run Windows in
  standard mode or real mode? To test this, start Windows by typing the
  following at the MS-DOS command prompt:

  " win /s " (without the quotation marks)

  If everything works correctly in Windows, you know that the problem is related
  only to running Windows in 386 enhanced mode.

  If the problem is specifically related to 386 enhanced mode, you may be
  loading SYMEVNT.386 from Norton Utilities 8.0. For more information about
  SYMEVNT.386, query in the Microsoft Knowledge Base on the following words:

  " symevnt.386 and norton " (without the quotation marks)

  If the problem is specifically related to 386 enhanced mode but you are not
  loading SYMEVNT.386, using the switches below may lessen the problem. Add
  these switches to the SYSTEM.INI file in the [386Enh] section in the order
  shown. If you find one of the switches works, you can try removing previous
  switches that had no effect. Note that the switches listed in item (b) should
  be added or removed as a pair. (See the MORE INFORMATION section of this
  article for an explanation of these switches.)

  a. IRQ9GLOBAL=YES

  b. HIGHFLOPPYREADS=NO
     EMMEXCLUDE=E000-EFFF

  c. VirtualHDIrq=OFF

6. Insert a semicolon (;) before the Load= and Run= lines in the WIN.INI file to
  ensure that nothing else is being loaded that could cause a problem.

7. Check to see if you can successfully issue commands in Windows at the MS-DOS
  command prompt. If commands work at the MS-DOS level, it indicates a BIOS or
  hard disk drive/floppy controller BIOS problem.

8. Is the floppy disk drive icon displayed in File Manager? If not, check your
  BIOS version and contact your hardware manufacturer for an update.

9. Disable any BIOS and video shadowing. Each computer may have a different way
  of disabling its shadowing. You will need to check your system documentation
  and follow the instructions provided there to perform this task.

10. Check for third-party or external floppy disk drivers.

11. Check the type and version of MS-DOS. MS-DOS versions earlier than 3.3 do
  not support 1.44-MB drives.

12. Check for hardware devices that may be using the same IRQ as the floppy disk
  drive controller. (By default, the floppy disk drive controller uses IRQ 6.)

13. Check to see if an IDE ATIO card is in use. This is an integrated card that
  contains a game port, serial port, parallel port, IDE, and floppy disk drive
  controller. Remove this card and insert a card that has only the IDE floppy
  disk drive controller on it.

MORE INFORMATION
================

The following paragraphs explain the switches used in step 5 above.

IRQ9Global=<boolean>
--------------------

Default: No

Purpose: If enabled, this switch converts IRQ9 masks to global. Enable this
setting if your system stops responding (hangs) when accessing a floppy disk
drive, or make sure your system accesses the floppy disk drive before you start
Windows.

HighFloppyReads=<boolean>
-------------------------

Default: Yes

Purpose: Normally, Windows turns a DMA verify to the area E000:0000- EFFF:FFFF
into a read. In rare cases, this might cause the system to fail because some
software might, as a result, write over the system's shadow RAM if you have it
in this area. If this happens, disable this setting and set EMMExclude to
E000-EFFF.

EMMExclude=<paragraph-range>
----------------------------

Default: None

Purpose: Specifies a range of memory that Windows will not scan to find unused
address space. This has the side effect of turning off the RAM and ROM search
code for the range. The range (two paragraph values separated by a hyphen) must
be between A000 and EFFF. This scanning can interfere with some adapters that
use the same memory area. The starting value is rounded down and the ending
value is rounded up to a multiple of 16K. For example, you could set
EMMExclude=C800-CFFF to prevent Windows from scanning the addresses C800:0000
through CFFF:000F. You can specify more than one range by including more than
one EMMExclude line.

VirtualHDIrq=<boolean>
----------------------

Default: On

Purpose: If enabled, Windows in 386 enhanced mode can terminate interrupts from
the hard disk controller, bypassing the ROM routine that handles these
interrupts. Some hard disk drives may require this setting to be disabled for
interrupts to be processed correctly. If this setting is disabled, the ROM
routine handles the interrupts, which slows down system performance.

Additional query words: tshoot 3.00 3.00a 3.10 3.11 central point norton format

======================================================================
Keywords          :  
Technology        : kbWin3xSearch kbZNotKeyword3 kbWin300 kbWin300a kbWin310 kbWin311
Version           : WINDOWS:3.0,3.0a,3.1,3.11

=============================================================================

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