The debugger will detect the presence of the function __DebugBreak, which will be part of the application if you linked it with the linker option for C-SPY emulated I/O.

In this case, the debugger will automatically set a breakpoint at the __DebugBreak function.

When your application calls a function in the DLIB low-level I/O interface, for example, open, the __DebugBreak function is called, which will cause the application to stop at the breakpoint and perform the necessary services.

The execution will then resume.