h6. [[Programmer's Reference Manuals]] h6(. » [[Vectors]] h6((. » [[Software Vector Numbers]] h6(((. » IrqV h2. Unknown IRQ Vector (2) |_<^{width:3em}. Entry |<^. | |\2<^. None| h4. Use This vector is called when an unknown IRQ is detected. It must not be called with [[OS_CallAVector]]. h4. Notes It was provided in the Arthur OS to allow hardware expansion to generate IRQs. RISC OS provides a new, more efficient method, and this vector is kept for compatibility. h4. See also * [[OS_CallAVector]] * [[Software Vector Numbers]]