Another major addition for the 6809 was one of the earliest dedicated hardware multipliers, which took 8-bit numbers in the A and B accumulators and produced a result in A+B, known collectively as D. It also added a new fast interrupt style, which automatically saved only the program counter and condition code register before calling the interrupt code, whereas the original style in the 6800, now referred to as "normal", saved out all of the registers and thus took additional cycles before the interrupt code was called, and more to unwind the stack on exit.