ENCODER INCREMENTAL, HOW CAN I SEE VALUES ON PC

Hi everyone (sorry for my poor English).
I have an incremental rotary hohner encoder, from it comes out a serial port (male)
 which if I'm not mistaken emits signals of the ttl type (square wave, 8 channels or A, A ', B, B', 0,0 ', +, -);
 I would like to know how to somehow connect the encoder to the pc in order to obtain information on the pc (bit)
 regarding the rotation of the encoder. Thanks and sorry for the ignorance