Abstract: This invention relates to personal computers, and to the handling of input/output signals exchanged between a microprocessor included within a personal computer and devices remote from the microprocessor. In addition to the microprocessor and a system board mounting the microprocessor, a personal computer in accordance with this invention has an input/output signal processing circuit for performing logical operations on digital signals passing to and from the microprocessor and preparing such signals for operative communication between the microprocessor and devices remote from the microprocessor, a second circuit board for mounting the circuit, a board connector mounting the second circuit board on the system board, an input/output connector for passing signals to and from the circuit for receipt from and delivery to devices remote from the microprocessor, and a signal communicating member extending between the circuit and the input/output connector for operatively communicating signals therebetween.