MS-DOS-Based Apps May Not Time-Slice Well Under WFWG 3.11

• Microsoft Windows for Workgroups version 3.11

SYMPTOMS

When 32-bit file access is enabled and 32-bit disk access is not, your computer does not accept keyboard input and then appears to stop responding (hang) in either an MS-DOS Prompt session or in an MS-DOS-based application. After you type a few characters, the machine appears to hang, and then the buffer empties, effectively pasting your text into the application very quickly.

NOTE: Many machines are configured to behave this way (for example, those with disk drive controllers that are not Western Digital (WD) 1003 compatible and those using disk-compression schemes other than MS-DOS 6.2 DoubleSpace).

CAUSE

When 32-bit file access is enabled without 32-bit disk access being enabled, Windows for Workgroups 3.11 uses the real-mode mapper. Since the real-mode mapper presents a synchronous interface to 32-bit file access, it prevents other system events from occurring simultaneously with disk access. This problem occurs when a large amount of data has accumulated in the cache and must be flushed immediately because of a disk reset (CTRL+C) or critical error. During the time that the data is being written to the drive, other system events are ignored.