Notes: 4/12/99 Comparison of the Audio Boards being used on the ASC-A/A+ and SENS PRO 500/520 systems. 234713-033 PCB Part Number should be BA41-10018T, 'WITHOUT' the modem connector. 234713-050 PCB Part Number should be BA41-10018T, 'WITH' the modem connector. 234589-258 PCB Part Number should be BA41-10016Q, without the modem connector.