[net.micro.pc] Interrupts with Microsoft C

boykin@datagen.UUCP (06/05/86)

>I have an interrupt service routine which is linked with
>my Microsoft 'C' application program. When the program is started
>it installs the pointer to the service routine in the vector table.
>As soon as the first interrupt is generated I get a stack overflow 
>message on the screen and the system hangs. If I disable the external
>interrupt source everything works fine. Sounds like a problem in the 
>interrupt service routine.
>
>	Thank You,
>
>	John Antrosiglio
>	ATT-Bell Labs
>	ihnp4!hou2f!jca

Unfortunately, you didn't provide all the information necessary to
diagnose the problem, however, it sounds like the problem may be due
to your interrupt service routine calling a C function.  Unless you
purposely disable it, MSC puts a call to a function called _chkstk
at the beginning of each function.  If you've run out of stack space,
the program terminates.  This isn't a good thing to do if you're at
interrupt level!

I don't remember what compiler option gets rid of this test, but it
is in the MSC manual.  If your assembler routine is NOT calling an
MSC function, I have no idea what your problem is!

Joe Boykin
Data General Corp.
{allegra, ihnp4, decvax}!datagen!boykin