1DR(Narrow resolution bandwidths min 10Hz)/ 1DS(Preamp)/ B72(Expansion Memory)/ 1D5( High stability frequency reference)/ BAC(cdmaOne measurement)/ 231(ESA to 89600 series software link update)/ A4H( GPIB and Centronics interface)/ BAA(FM demodulation)/ B7D(Digital signal processing and fast ADC)/ B7E(RF communications hardware)