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Appendix D
PC Card Questions and Answers for Windows 3.1
DAQCard-DIO-24 User Manual
D-2
©
National Instruments Corporation
Operation
My PC Card works when inserted before power-on time, but it does
not work when hot inserted. What is wrong?
You may have an interrupt conflict. If you have a utility such as
MSD.EXE
, run it to determine the allocated interrupts, then refer to
question 5 in the Resources section.
MSD.EXE
is usually shipped with
Microsoft Windows.
My computer locks up when I use a PC Card. What should I do?
This usually happens because Card Services allocated an unusable
interrupt level to the PC Card. For example, on some computers,
interrupt level 11 is not routed to PC Cards. If Card Services is not
aware of this, it may assign interrupt 11 to a PC Card even though the
interrupt is not usable. When a call uses the interrupt, the interrupt never
occurs, and the computer locks up waiting for a response. For
information about how to locate an interrupt that is free to be used, refer
to the Resources section.
Resources
How do I determine if I have a memory conflict?
If no PC Cards are working at all, it is probably because a memory
window is not usable. Card Services uses a 4 kB memory window for
its own internal use. If the memory cannot be used, then Card Services
cannot read the Card Information Structure (CIS) from the DAQCard
EPROM, which means it cannot identify boards.
There are two different methods you can use when Card Services has a
problem reading the CIS. First, you can determine which memory
window Card Services is using, and then exclude that window from use
by Card Services and/or the memory manager. Second, you can attempt
to determine all of the memory that Card Services can possibly use and
then exclude all but that memory from use by Card Services.
How do I determine all of the memory that Card Services can use?
One way to find out which memory addresses Card Services can use is
to run a utility such as
MSD.EXE
that scans the system and tells you how
the system memory is being used. For example, if you run such a
memory utility and it tells you that physical addresses C0000 to C9FFF