So I'm trying to detect through Visual Basic 6.0 when a voltage change occurs on one of the pins of the serial/parallel port. The whole thing is pretty simple; no data transfer/handshaking/etc ...

Launch and terminate applications in Visual ... Basic 6.0 rely on shell commands. However, you can also accomplish this task by using API functions. Time to code Let’s create a simple VB project ...

In terms of value access, they're a lot like global variables, yet scoped to just a single routine: /* ----- C language example */ void DoSomeWork ... can easily emulate this Visual Basic feature in C ...