You can purchase an unmodified CMXXX USB sound card and solder GPIO directly for COS, PTT, and CTCSS. However, it's not for the faint of heart. Doing this requires a steady hand and magnification equipment to solder to the tiny leads on the circuit board. | You can purchase an unmodified CMXXX USB sound card and solder GPIO directly for COS, PTT, and CTCSS. However, it's not for the faint of heart. Doing this requires a steady hand and magnification equipment to solder to the tiny leads on the circuit board. |