Hello,
we could not get any OpenGL application compiled with ftn95 (tested with versions from 5.21 up to the current release) to run with a recent ATI card (Radeon HD 5770) on windows7 64bit. This has been verified on different systems (including win7 64bit enterprise, as well as win7 64bit RC). Graphics card drivers from Catalyst 9.12 to the current 10.2 have been tested, driver settings do not have an effect on the problem.
The problem manifests in a hard crash of the application (message 'application does not work any longer' without further useful information) which happens even with a plain fortran application that has only a %og and no additional processing related to GUI/OpenGL.
Using an external debugger the problem has been traced down to the ATI OpenGL driver component where a floating point exception happens. This is a result of ftn95 changing the default fpu control word when parsing/processing the winio@ line that contains the %og command. The (working) default of the fpu control word is 0x27f (all exceptions masked) whereas ftn95 changes this to 0x360 (all exceptions trigger an fpu exception) which lets the wglCreateContext (implicitly called by %og) to fail.
Please let me know if more information is needed, it would be nice to get response/verification of the issue soon as it effectively limits the use of ftn95-compiled OpenGL applications on current systems.
Thanks.