Need help with Digital system project.

[MglMogul]

Hello, I need help in designing a schematic for Basketball scoreboard for my Digital Systems Class. I want to start this project but I don't know where and how to began as I am kind of lost right now. I need someone to at least help in the right direction. I am thinking that the basketball scoreboard should basically be something like this: scoreboard that has time that starts from or resets to 12:00 minutes. The time will decrease from 12:00 minutes and it can be paused at any time. There will be a quarter numbers from 1 to 4 as well as which team has the possession of the ball. It will display how many timeouts left from each team starting from 6 and how many fouls each team has. Last but not least, the scoreboard will have the score of each time that each has 3 digits as most basketball games can go over 100 points.
Any help will be appreciated. Thank you.
I can't use a kit or any sorts of materials like that. It is a final project for class and I only can use what is listed below if need be.

Integrated Circuits: Display:
TTL MAN-72 (or equivalent)
7400 7492A
7402 7493A
7404 74121
7408 74LS139A
7447A 74LS153
7474 74175
74LS76A 74LS189
7483A 74191
7485 74195
7486
Resistors:
An assortment of 14-W resistors is suggested.
most widely used values are 330 £2, 390 Q 1.0 kQ2 kQ, 10 kQ, and 100 k£l
Capacitors:
One 0.01 |nF Three 0.1 jaF One 1.0 \xF One 100 juF
CMOS:
4069 4071 4081 1405IB 14532B
Linear:
LM555 LM741 ADC0804 MC1408
Miscellaneous:
One 1 k Q potentiometer
LEDs Signal diodes (1N914 or equivalent)
4-position DIP switch
Two SPST N.O. pushbuttons
Two CdS photocells (Jameco 120299 or equivalent)
Solderless breadboard (Radio Shack #276-174 or
equivalent)

 

[panic mode]

i would start by defining requirements, then work from there.
for example i would imagine that there is few buttons for the user:
a_score_1, a_score_2, a_score_3, add 1-3 points to team A
b_score_1, b_score_2, b_score_3, add 1-3 points to team B
reset all, clears all counters and displays zeroes,
and probably an undo button or buttons (to wind the score down when points were awarded by accident).
depending how you want it done this (and reset) can be combined into preset logic (preset zero, clears displays; preset nn, displays nn) .
i don't hink i see any decade counter so you may need to adapt binary counter to count 0-9.
7447A is a 7seg decoder, (you do realize you will need multiples of some of the parts?).

 

[MglMogul]

Hello, Yea I realize that. I have took a picture of the schematics of my circuits on Multisim 11. I think these two needs tweaking in order to get every function I want on the Scorekeeper that goes up to 150 at least and the countdown timer from 12 minutes.

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