How much software must I uninstall to change External compatibility mode

[codym]

I have found a problem with CVI 6.0 and the sizeof() operator which gives an improper result if the external compatibility mode is Microsoft C/C++.
with External compatibility mode set to Borland the sizeof operator returns the correct size of a data typedef struct{size = 436 bytes} under MS mode the sizeof operator returns sizeof(struct) = 440.
To fully test this problem I need to change the compatibility mode back to Borland from the install mode of MS.
when I run the install progrma to change the compatibility mode I get the aborted load message for nidaq, easyio, imaq and other libraries. I have a lot of NI software on this machine do I need to uninstall it ALL????? or is there a subset or
shortcut I can follow frm the install discs.
Thanks CMM
P.S. if this problem is persistent I think you may have a problem. If I find it so, I'll send you a note somehow or call a service rep.

[aperez]

Hi Cody,

It is entirely possible (and correct) for the sizeof() operator to yield different results according to the compatibility mode. Borland uses different structure packing than MSVC. You should be using #pragmas pack preprocessor statements to define the maximum alignment value for sorting memmbers of a structure in memory.

See the following knowledgebase article:

http://pong.ni.com/public.nsf/websearch/5F94E0FD2BD4732786256547007D8EBB?OpenDocument

If you still want to change compatibility modes to test this issue (although trust me, it is not), you'll have to run the NI-DAQ setup.exe to install the DAQ libraries for the new compatibility mode. This will not reinstall NI-DAQ. It will just take you to the DAQ libraries section of the installer.


Let me know if you have other related questions
Regards,
Azucena