simple calculator (sum and sub) for single digit decimal numbers using verilog. The code is ment to run on an FPGA board using a PS/2 keyboard. Simply connect the keyboard to your FPGA board and start typing numbers. Make sure you use only the numpad for each number the '-' or '+' signs for sub and sum and hit enter to display a final result. Also don't forget to connect the output of the codes to the necessary pins using the cvs file.