Any decimal digit from zero through nine can be displayed by lighting the appropriate segments of a 7-segment display, as shown below in Figure 1:

THE SEVEN-SEGMENT DISPLAY

Figure 1: Segment definitions of a 7-segment display.

The desired decimal digit is expressed in binary-coded-decimal (BCD) format, and then used as an input to a logic network which controls the seven segments. 
For this project, you will develop a multiple-output logic network that drives a 7-segment display, yielding all ten decimal digits. Here is how you will proceed:

1. The input variables will be the BCD representations of the decimal digits 0-9 (use switches 0-3 on your DE-2 board: SW0= LSB, SW3= MSB).

2. Using Karnaugh maps, determine the seven output functions for controlling each of the seven segments, in minimum SOP form. Using Don't Cares will greatly simplify your output functions.

3. Express the seven output functions in AND-OR (POS) form.

4. (Optional) Rewrite output functions in step3 using NOR gates (NOT gates are permissible).

You will display the digit on the left 7-segment digit on your DE-2 board.  Refer to the DE-2 Manuals regarding how to enable a specific digit on this display.  Hint: Applying a logic low level to a segment causes it to light up and applying a high level turns it off.

Design Constraints: Use 2-, 3-, or 4-input  gates, except that inverters may be used to invert input variables. A design with 20 or fewer total  gates ( AND and OR) is required.