Q
QSET
CLR
D
Q
QSET
CLR
D
Q
QSET
CLR
D
4
Q
QSET
CLR
D 4
4
or
Q
QSET
CLR
D
Q
QSET
CLR
D
Q
QSET
CLR
D
Q
QSET
CLR
D

D0
D1
D2
D3
Q0
Q1
Q2
Q3
Q0
Q1
Q2
Q3
CLR
4
5
12
13
9
1
14
11
6
3
15
10
7
2
U1
74HCT175

74HCT283
4 bit full
adder
16 15 14 13 12 11 10 9
1 2 3 4 5 6 7 8
VCC B2 A2 S2 A3 B3 S3 C4
S1 B1 A1 S0 A0 B0 C0 GND
Full
Adder
Full
Adder
Full
Adder
Full
Adder
C1C2
C3 C4
C0

A0
A1
A2
A3
B0
B1
B2
B3
S0
S1
S2
S3+
C0
C4
or
+
A
B
S
4
4
4
C0
C4

A0
A1
A2
A3
B0
B1
B2
B3
S0
S1
S2
S3+
C0
C4
5
3
14
12
6
2
15
11
4
1
13
10
7
9
U1
74HCT283


Inputs and Outputs
IO Board


1: TX
2: RX
3: SSD Cathode
4: SSD Decimal Point
5-11: SSD Segments G to A
12-15: Buttons B3 to B0
16: Logic Probe
17-24: LEDs L0 to L7
25-32: Switches S0 to S7

Input: A
Output: X0

(Use sensible names)
B3
B2
B1
B0
12
13
14
15
IO1
IOBOARD 25
26
27
28
IO1
IOBOARD
IO1
IOBOARD
29
30
31
32
H
G
F
E
D
C
B
A X0
X1
X2
X3
17
18
19
20
X4
X5
COUT
OFLOW
21
22
23
24

B3
B2
B1
B0
12
13
14
15
IO1
IOBOARD 25
26
27
28
IO1
IOBOARD
IO1
IOBOARD
29
30
31
32
H
G
F
E
D
C
B
A X0
X1
X2
X3
17
18
19
20
X4
X5
COUT
OFLOW
21
22
23
24