With a cursory exploration, it appears that I am unable to attach interrupt handlers from C++ code. Is this indeed true? Is there a hardware limitation with the BBB that does not allow interrupts? Though tedious to write, I have written Linux device drivers for the Intel architecture but that is a dearth of info for the BBB architecture. I would dearly love to add interrupt handlers in C++ with the ease of the Arduino DUE. Before you start harping about going back to the Arduino DUE or other mundane arguments of DUE vs. BBB, a glaring deficit the Arduino DUE is that the operating system does not support multi-threading. Multi-threading separates the embedded supporting systems from the want-to-bes. This is particularly apparent as the complexity of process control increases. However, at this point, BBB appears to have its own issues with external interrupt support. As with multi-threading, need for external interrupt support increases as the complexity of the process tneeds increases. Unless the external interrupting hardware does not require time critical response and has a detectable request time measured in milliseconds (no A Priori knowledge of when external hardware needs servicing) , polling is NOT a solution rather a software kludge. After all this prefacing, what is the state of interrupt capabilities from software with the BBB? Can it be accomplished with the development of a device driver? There are multiple ways to implement support but only if the underlying hardware of the BBB supports such external interrupts. Will switching from the default Angstrom to Ubuntu make any difference? There are hints of some sort RTOS available but does the RTOS have a standard tool chain as available with Angstrom and Ubuntu? Many questions I know, but before beginning a 3 man-year software development project, they need to be resolved.