ID Number: Q75283
3.00 3.10 3.11 3.14
MS-DOS
buglist3.00 buglist3.10 buglist3.11 buglist3.14
Summary:
PROBLEM ID: CV9108003
SYMPTOMS
In Microsoft DOS Extended CodeView (CV /X) versions 3.0, 3.1,
3.11, and 3.14, rapid CPU mode switching (from protected to real
mode) with heavy keyboard or disk activity may cause the keyboard to
behave strangely. For example, the keyboard may go into a shift-lock
state that highlights text and prints the keys as if one of the
shift keys is being held down. The behavior usually manifests itself
on slower processors such as the 80386sx and 80286. However, the
problem may occur on faster machines as well, depending on the
activity going on in CodeView.
CAUSE
One possible cause is rapidly scrolling through the source window
with the keyboard using either the ARROW keys for the PAGE UP or
PAGE DOWN keys. When CodeView cannot keep up with the CPU mode
switching, it may jump into the command window.
Another less common activity that may cause problems is floppy disk
drive activity. Any activity that cause hardware interrupts may cause
the behavior if CodeView cannot keep up with the CPU mode switches
along with the interrupts.
RESOLUTION/STATUS
Use a mouse to perform scrolling rather than the keyboard if
possible. If the keyboard seems to be in a shift-lock state, then
press both shift keys simultaneously to return to a normal state.
Microsoft has confirmed this to be a problem in CodeView versions
3.0, 3.1, 3.11 and 3.14. We are researching this problem and will
post new information here as it becomes available.
Additional reference words: 3.00 3.10