Kits
›
How a CPU Counts
RU
EN
ES
Contents
Introduction
History: how machines learned to add
Lesson 1. Gates and the half adder: 1 + 1 = 10
1.1. The idea: adding one digit
1.2. Building
1.3. Check
Lesson 1 paste (Cmd+I)
Lesson 2. The full adder and 4 bits: the carry runs through the digits
2.1. The idea: column addition
2.2. Building
2.3. Check
Lesson 2 paste (Cmd+I)
Lesson 3. Negative numbers and subtraction: two's complement
3.1. The idea: numbers on a circle
3.2. Flags
3.3. Building
3.4. Check
Lesson 3 paste (Cmd+I)
Lesson 4. 8 bits and comparison: CMP is subtraction
4.1. The idea: two halves
4.2. The idea: comparison is subtraction
4.3. Building
4.4. Check
Lesson 4 paste (Cmd+I)
Lesson 5. The ± calculator: the minus on a lamp, the magnitude on the display
5.1. The idea: the magnitude is one more subtraction
5.2. Building
5.3. Check
Lesson 5 paste (Cmd+I)
Lesson 6 (bonus). Decimal math: add six
6.1. The idea: a digit in four bits
6.2. Why the display is in HEX mode
6.3. Building
How to set the digits
6.4. Check
Lesson 6 paste (Cmd+I)
Summary
All the parts
Instructions in pictures
Instructions in pictures
Download PDF — the whole book
kh
HARDWARE BASICS
build kits · khanin.info
Building
instructions
HB-02
How a CPU Counts
lessons 1–6 · from a bit to a calculator
simulator: cs.khanin.info
© 2026 Daniil Khanin · khanin.info · HB-02
1
How to read these instructions
3
step number — follow strictly in order
AND
2×
1
6×
parts for this step: how many to place
AND
A
x
B
y
Y
z
a part with labels on its pins
CLK
CLK
labels with the same name are connected
A
Y
chip ports: input [ and output ]
DFF
blue frame — building a chip
CANVAS
grey tab — the main canvas
low
yellow ring — what has changed
remove a part together with its labels
2×
double-click a label — new name
3
chip built in the lesson with this number
check: this is how it should work
Keys
V
VCC (1)
G
GND (0)
N
transistor
I
switch
O
lamp
L
label
K
clock
U
button
[
port in
]
port out
Ctrl+G — into a chip
on a Mac Ctrl = Cmd
© 2026 Daniil Khanin · khanin.info · HB-02
2
A little history
1642
Pascal: wheels
1673
Leibniz: the drum
1937
Stibitz: relays
1971
Intel 4004
now
you build it
People added on the abacus too. The hard part is the carry: ten piled up — clear the digit
and add one to the next. Pascal built a machine where a wheel going from 9 to 0
pushed the next one by itself. Leibniz's idea grew into arithmometers — in every office until the 1970s.
In 1937 George Stibitz built a binary adder on his kitchen table from two relays,
a battery and light bulbs: lit is 1, dark is 0. Exactly what you build in the first lesson.
Relays gave way to vacuum tubes, tubes to transistors, but the adder stayed in every processor:
it adds, subtracts, compares and computes addresses. The first microprocessor, the Intel 4004,
was made for a calculator — so it could also do the decimal "+6" correction.
+1
Intel and Bell Labs are trademarks of their respective owners. This kit is not affiliated with or endorsed by them.
© 2026 Daniil Khanin · khanin.info · HB-02
3
1
Half adder
gates from transistors, then 1 + 1 = 10
kh
HB-02
1
A0
1
B0
HA
A
B
S
C
C
S
1 + 1 = 10
IN
13×
OUT
8×
P
11×
N
11×
VCC
1×
GND
1×
0
2×
2×
∞
Ctrl
+
G
NOT
NAND
NOR
AND
OR
XOR
HA
© 2026 Daniil Khanin · khanin.info · HB-02
4
NOT
1
IN
1×
OUT
1×
P
1×
N
1×
6×
I0
O0
VCC
O0
G
P
I0
O0
GND
G
N
I0
2
Ctrl
+
G
Library
…
Chip N
2×
Library
…
NOT
Enter
NOT
I0
O0
© 2026 Daniil Khanin · khanin.info · HB-02
5
NAND
3
IN
2×
OUT
1×
P
2×
N
1×
9×
I0
I1
O0
VCC
O0
G
P
I0
VCC
O0
G
P
I1
O0
mid
G
N
I0
4
N
1×
3×
mid
GND
G
N
I1
5
Ctrl
+
G
Library
…
Chip N
2×
Library
…
NAND
Enter
NAND
I0
I1
O0
© 2026 Daniil Khanin · khanin.info · HB-02
6
NOR
6
IN
2×
OUT
1×
P
2×
N
1×
9×
I0
I1
O0
VCC
mid
G
P
I0
mid
O0
G
P
I1
O0
GND
G
N
I0
7
N
1×
3×
O0
GND
G
N
I1
8
Ctrl
+
G
Library
…
Chip N
2×
Library
…
NOR
Enter
NOR
I0
I1
O0
© 2026 Daniil Khanin · khanin.info · HB-02
7
AND
9
IN
2×
OUT
1×
P
2×
N
1×
9×
I0
I1
O0
VCC
n
G
P
I0
VCC
n
G
P
I1
n
mid
G
N
I0
10
N
2×
P
1×
9×
mid
GND
G
N
I1
VCC
O0
G
P
n
O0
GND
G
N
n
11
Ctrl
+
G
Library
…
Chip N
2×
Library
…
AND
Enter
AND
I0
I1
O0
© 2026 Daniil Khanin · khanin.info · HB-02
8
OR
12
IN
2×
OUT
1×
P
2×
N
1×
9×
I0
I1
O0
VCC
mid
G
P
I0
mid
n
G
P
I1
n
GND
G
N
I0
13
N
2×
P
1×
9×
n
GND
G
N
I1
VCC
O0
G
P
n
O0
GND
G
N
n
14
Ctrl
+
G
Library
…
Chip N
2×
Library
…
OR
Enter
OR
I0
I1
O0
© 2026 Daniil Khanin · khanin.info · HB-02
9
XOR
15
IN
2×
OUT
1×
OR
1×
NAND
1×
AND
1×
9×
I0
I1
O0
OR
I0
I0
I1
I1
O0
o
NAND
I0
I0
I1
I1
O0
n
AND
I0
o
I1
n
O0
O0
16
Ctrl
+
G
Library
…
Chip N
2×
Library
…
XOR
Enter
XOR
I0
I1
O0
© 2026 Daniil Khanin · khanin.info · HB-02
10
HA
CANVAS
17
IN
2×
OUT
2×
XOR
1×
AND
1×
6×
A
B
S
C
XOR
I0
A
I1
B
O0
S
AND
I0
A
I1
B
O0
C
18
Ctrl
+
G
Library
…
Chip N
2×
Library
…
HA
Enter
HA
A
B
S
C
19
VCC
1×
GND
1×
0
2×
4×
VCC
VCC
GND
GND
0
A
0
B
© 2026 Daniil Khanin · khanin.info · HB-02
11
CANVAS …
20
HA
1×
2×
6×
HA
A
A
B
B
S
S
C
C
S
C
0
A0
1
B0
C
S
0 + 1 = 01
1
A0
1
B0
C
S
1 + 1 = 10
© 2026 Daniil Khanin · khanin.info · HB-02
12
2
4 bits
the full adder FA and four digits in a chain
kh
HB-02
A
0
A3
1
A2
1
A1
1
A0
B
1
B3
0
B2
0
B1
1
B0
16
S
7 + 9 = 16
IN
12×
OUT
7×
HA
2×
1
OR
1×
1
0
8×
4b
0
A
3×
∞
Ctrl
+
G
FA
ADDER4
© 2026 Daniil Khanin · khanin.info · HB-02
13
CANVAS
FA
1
Delete
0
A
0
B
HA
A
A
B
B
S
S
C
C
S
C
2
IN
3×
OUT
2×
HA
2×
1
OR
1×
1
11×
A
B
CI
S
CO
HA
A
A
B
B
S
s1
C
c1
HA
A
s1
B
CI
S
S
C
c2
OR
I0
c1
I1
c2
O0
CO
© 2026 Daniil Khanin · khanin.info · HB-02
14
FA …
ADDER4
3
Ctrl
+
G
Library
…
Chip N
2×
Library
…
FA
Enter
FA
A
B
CI
S
CO
4
IN
9×
OUT
5×
A0
A1
A2
A3
B0
B1
B2
B3
CI
S0
S1
S2
S3
CO
5
FA
3×
15×
FA
A
A0
B
B0
CI
CI
S
S0
CO
c1
FA
A
A1
B
B1
CI
c1
S
S1
CO
c2
FA
A
A2
B
B2
CI
c2
S
S2
CO
c3
© 2026 Daniil Khanin · khanin.info · HB-02
15
ADDER4 …
CANVAS
6
FA
1×
5×
FA
A
A3
B
B3
CI
c3
S
S3
CO
CO
7
Ctrl
+
G
Library
…
Chip N
2×
Library
…
ADDER4
Enter
ADDER4
A0
A1
A2
A3
B0
B1
B2
B3
CI
S0
S1
S2
S3
CO
8
0
5×
5×
0
A0
0
A1
0
A2
0
A3
0
B0
© 2026 Daniil Khanin · khanin.info · HB-02
16
CANVAS …
9
0
3×
3×
0
B1
0
B2
0
B3
10
ADDER4
1×
14×
ADDER4
A0
A0
A1
A1
A2
A2
A3
A3
B0
B0
B1
B1
B2
B2
B3
B3
CI
GND
S0
S0
S1
S1
S2
S2
S3
S3
CO
S4
11
4b
0
A
3×
4b
DEC
A
4b
DEC
B
8b
DEC
S
A
0
A3
0
A2
1
A1
1
A0
B
0
B3
1
B2
0
B1
0
B0
7
S
A
0
A3
1
A2
1
A1
1
A0
B
1
B3
0
B2
0
B1
1
B0
16
S
© 2026 Daniil Khanin · khanin.info · HB-02
17
3
Subtraction and flags
two's complement, the SUB switch, lamps C Z N V
kh
HB-02
A
0
A3
0
A2
1
A1
1
A0
B
0
B3
1
B2
0
B1
1
B0
1
SUB
1110
S
C
Z
N
V
3 − 5 = −2
IN
10×
OUT
6×
XOR
6×
1
ADDER4
1×
2
AND
1×
1
0
9×
OR
2×
1
NOR
1×
1
4×
4b
0
A
3×
∞
Ctrl
+
G
ADDSUB4
© 2026 Daniil Khanin · khanin.info · HB-02
18
CANVAS
1
Delete
0
A0
0
A1
0
A2
0
A3
0
B0
0
B1
0
B2
0
B3
4b
DEC
A
2
Delete
4b
DEC
B
8b
DEC
S
3
Delete
ADDER4
A0
A0
A1
A1
A2
A2
A3
A3
B0
B0
B1
B1
B2
B2
B3
B3
CI
GND
S0
S0
S1
S1
S2
S2
S3
S3
CO
S4
© 2026 Daniil Khanin · khanin.info · HB-02
19
ADDSUB4
4
IN
10×
OUT
6×
A0
A1
A2
A3
B0
B1
B2
B3
SUB
CI
S0
S1
S2
S3
CO
V
5
XOR
3×
1
9×
XOR
I0
B0
I1
SUB
O0
bx0
XOR
I0
B1
I1
SUB
O0
bx1
XOR
I0
B2
I1
SUB
O0
bx2
6
XOR
1×
1
3×
XOR
I0
B3
I1
SUB
O0
bx3
7
ADDER4
1×
2
14×
ADDER4
A0
A0
A1
A1
A2
A2
A3
A3
B0
bx0
B1
bx1
B2
bx2
B3
bx3
CI
CI
S0
S0
S1
S1
S2
S2
S3
S3
CO
CO
© 2026 Daniil Khanin · khanin.info · HB-02
20
ADDSUB4 …
CANVAS
8
XOR
2×
1
AND
1×
1
9×
XOR
I0
A3
I1
S3
O0
va
XOR
I0
bx3
I1
S3
O0
vb
AND
I0
va
I1
vb
O0
V
9
Ctrl
+
G
Library
…
Chip N
2×
Library
…
ADDSUB4
Enter
ADDSUB4
A0
A1
A2
A3
B0
B1
B2
B3
SUB
CI
S0
S1
S2
S3
CO
V
10
0
5×
5×
0
A0
0
A1
0
A2
0
A3
0
B0
© 2026 Daniil Khanin · khanin.info · HB-02
21
CANVAS …
11
0
4×
4×
0
B1
0
B2
0
B3
0
SUB
12
ADDSUB4
1×
16×
ADDSUB4
A0
A0
A1
A1
A2
A2
A3
A3
B0
B0
B1
B1
B2
B2
B3
B3
SUB
SUB
CI
SUB
S0
S0
S1
S1
S2
S2
S3
S3
CO
C
V
V
13
OR
2×
1
NOR
1×
1
9×
OR
I0
S0
I1
S1
O0
z01
OR
I0
S2
I1
S3
O0
z23
NOR
I0
z01
I1
z23
O0
Z
© 2026 Daniil Khanin · khanin.info · HB-02
22
CANVAS …
14
4×
4×
C
Z
S3
V
15
4b
0
A
3×
4b
DEC
A
4b
DEC
B
4b
BIN
S
A
0
A3
0
A2
1
A1
1
A0
B
0
B3
1
B2
0
B1
1
B0
1
SUB
1110
S
C
Z
N
V
A
0
A3
1
A2
0
A1
1
A0
B
0
B3
1
B2
0
B1
1
B0
1
SUB
0000
S
C
Z
N
V
A
0
A3
1
A2
1
A1
1
A0
B
0
B3
0
B2
0
B1
1
B0
0
SUB
1000
S
C
Z
N
V
© 2026 Daniil Khanin · khanin.info · HB-02
23
4
8 bits and comparison
two ADDSUB4 in a chain, lamps = < >
kh
HB-02
A
0
A7
0
A6
0
A5
0
A4
0
A3
1
A2
0
A1
1
A0
B
0
B7
0
B6
0
B5
0
B4
1
B3
0
B2
0
B1
1
B0
1
SUB
A=B
A<B
A>B
5 − 9: A < B
IN
17×
OUT
10×
ADDSUB4
2×
3
0
17×
OR
6×
1
NOR
1×
1
NOT
2×
1
AND
4×
1
7×
4b
0
A
3×
∞
Ctrl
+
G
ADDSUB8
© 2026 Daniil Khanin · khanin.info · HB-02
24
CANVAS
1
Delete
0
A0
0
A1
0
A2
0
A3
0
B0
0
B1
0
B2
0
B3
0
SUB
2
Delete
OR
I0
S0
I1
S1
O0
z01
OR
I0
S2
I1
S3
O0
z23
NOR
I0
z01
I1
z23
O0
Z
C
Z
S3
V
4b
DEC
A
4b
DEC
B
3
Delete
4b
BIN
S
© 2026 Daniil Khanin · khanin.info · HB-02
25
CANVAS …
4
Delete
ADDSUB4
A0
A0
A1
A1
A2
A2
A3
A3
B0
B0
B1
B1
B2
B2
B3
B3
SUB
SUB
CI
SUB
S0
S0
S1
S1
S2
S2
S3
S3
CO
C
V
V
© 2026 Daniil Khanin · khanin.info · HB-02
26
ADDSUB8
5
IN
17×
OUT
10×
A0
A1
A2
A3
A4
A5
A6
A7
B0
B1
B2
B3
B4
B5
B6
B7
SUB
S0
S1
S2
S3
S4
S5
S6
S7
CO
V
6
ADDSUB4
1×
3
15×
ADDSUB4
A0
A0
A1
A1
A2
A2
A3
A3
B0
B0
B1
B1
B2
B2
B3
B3
SUB
SUB
CI
SUB
S0
S0
S1
S1
S2
S2
S3
S3
CO
c4
V
7
ADDSUB4
1×
3
16×
ADDSUB4
A0
A4
A1
A5
A2
A6
A3
A7
B0
B4
B1
B5
B2
B6
B3
B7
SUB
SUB
CI
c4
S0
S4
S1
S5
S2
S6
S3
S7
CO
CO
V
V
© 2026 Daniil Khanin · khanin.info · HB-02
27
ADDSUB8 …
CANVAS
8
Ctrl
+
G
Library
…
Chip N
2×
Library
…
ADDSUB8
Enter
ADDSUB8
A0
A1
A2
A3
A4
A5
A6
A7
B0
B1
B2
B3
B4
B5
B6
B7
SUB
S0
S1
S2
S3
S4
S5
S6
S7
CO
V
9
0
5×
5×
0
A0
0
A1
0
A2
0
A3
0
A4
10
0
5×
5×
0
A5
0
A6
0
A7
0
B0
0
B1
11
0
5×
5×
0
B2
0
B3
0
B4
0
B5
0
B6
12
0
2×
2×
0
B7
0
SUB
© 2026 Daniil Khanin · khanin.info · HB-02
28
CANVAS …
13
ADDSUB8
1×
27×
ADDSUB8
A0
A0
A1
A1
A2
A2
A3
A3
A4
A4
A5
A5
A6
A6
A7
A7
B0
B0
B1
B1
B2
B2
B3
B3
B4
B4
B5
B5
B6
B6
B7
B7
SUB
SUB
S0
S0
S1
S1
S2
S2
S3
S3
S4
S4
S5
S5
S6
S6
S7
S7
CO
C
V
V
14
OR
3×
1
9×
OR
I0
S0
I1
S1
O0
z01
OR
I0
S2
I1
S3
O0
z23
OR
I0
S4
I1
S5
O0
z45
15
OR
3×
1
9×
OR
I0
S6
I1
S7
O0
z67
OR
I0
z01
I1
z23
O0
z03
OR
I0
z45
I1
z67
O0
z47
© 2026 Daniil Khanin · khanin.info · HB-02
29
CANVAS …
16
NOR
1×
1
3×
NOR
I0
z03
I1
z47
O0
Z
17
NOT
2×
1
AND
1×
1
7×
NOT
I0
C
O0
nC
NOT
I0
Z
O0
nZ
AND
I0
SUB
I1
Z
O0
EQ
18
AND
3×
1
9×
AND
I0
SUB
I1
nC
O0
LT
AND
I0
C
I1
nZ
O0
cnz
AND
I0
SUB
I1
cnz
O0
GT
© 2026 Daniil Khanin · khanin.info · HB-02
30
CANVAS …
19
5×
5×
C
Z
S7
V
EQ
20
2×
2×
LT
GT
21
4b
0
A
3×
8b
DEC
A
8b
DEC
B
8b
DEC
S
A
0
A7
0
A6
0
A5
0
A4
0
A3
1
A2
1
A1
1
A0
B
0
B7
0
B6
0
B5
0
B4
0
B3
1
B2
1
B1
1
B0
1
SUB
0
S
=
<
>
A
0
A7
0
A6
0
A5
0
A4
0
A3
1
A2
0
A1
1
A0
B
0
B7
0
B6
0
B5
0
B4
1
B3
0
B2
0
B1
1
B0
1
SUB
252
S
=
<
>
A
1
A7
1
A6
0
A5
0
A4
1
A3
0
A2
0
A1
0
A0
B
1
B7
0
B6
0
B5
1
B4
0
B3
1
B2
1
B1
0
B0
1
SUB
50
S
=
<
>
© 2026 Daniil Khanin · khanin.info · HB-02
31
5
The ± calculator
the minus on a lamp, the magnitude on the display
kh
HB-02
A
0
A7
0
A6
0
A5
0
A4
0
A3
0
A2
1
A1
1
A0
B
0
B7
0
B6
0
B5
0
B4
0
B3
1
B2
0
B1
1
B0
1
SUB
−
2
M
3 − 5 = −2
0
17×
ADDSUB8
2×
4
2×
4b
0
A
3×
∞
© 2026 Daniil Khanin · khanin.info · HB-02
32
CANVAS
1
Delete
0
A0
0
A1
0
A2
0
A3
0
A4
0
A5
0
A6
0
A7
0
B0
2
Delete
0
B1
0
B2
0
B3
0
B4
0
B5
0
B6
0
B7
0
SUB
OR
I0
S0
I1
S1
O0
z01
© 2026 Daniil Khanin · khanin.info · HB-02
33
CANVAS …
3
Delete
OR
I0
S2
I1
S3
O0
z23
OR
I0
S4
I1
S5
O0
z45
OR
I0
S6
I1
S7
O0
z67
OR
I0
z01
I1
z23
O0
z03
OR
I0
z45
I1
z67
O0
z47
NOR
I0
z03
I1
z47
O0
Z
NOT
I0
C
O0
nC
NOT
I0
Z
O0
nZ
AND
I0
SUB
I1
Z
O0
EQ
4
Delete
AND
I0
SUB
I1
nC
O0
LT
AND
I0
C
I1
nZ
O0
cnz
AND
I0
SUB
I1
cnz
O0
GT
C
Z
S7
V
EQ
LT
© 2026 Daniil Khanin · khanin.info · HB-02
34
CANVAS …
5
Delete
GT
8b
DEC
A
8b
DEC
B
8b
DEC
S
6
Delete
ADDSUB8
A0
A0
A1
A1
A2
A2
A3
A3
A4
A4
A5
A5
A6
A6
A7
A7
B0
B0
B1
B1
B2
B2
B3
B3
B4
B4
B5
B5
B6
B6
B7
B7
SUB
SUB
S0
S0
S1
S1
S2
S2
S3
S3
S4
S4
S5
S5
S6
S6
S7
S7
CO
C
V
V
© 2026 Daniil Khanin · khanin.info · HB-02
35
CANVAS …
7
0
5×
5×
0
A0
0
A1
0
A2
0
A3
0
A4
8
0
5×
5×
0
A5
0
A6
0
A7
0
B0
0
B1
9
0
5×
5×
0
B2
0
B3
0
B4
0
B5
0
B6
© 2026 Daniil Khanin · khanin.info · HB-02
36
CANVAS …
10
0
2×
2×
0
B7
0
SUB
11
ADDSUB8
1×
4
27×
ADDSUB8
A0
A0
A1
A1
A2
A2
A3
A3
A4
A4
A5
A5
A6
A6
A7
A7
B0
B0
B1
B1
B2
B2
B3
B3
B4
B4
B5
B5
B6
B6
B7
B7
SUB
SUB
S0
S0
S1
S1
S2
S2
S3
S3
S4
S4
S5
S5
S6
S6
S7
S7
CO
C
V
V
12
ADDSUB8
1×
4
25×
ADDSUB8
A0
GND
A1
GND
A2
GND
A3
GND
A4
GND
A5
GND
A6
GND
A7
GND
B0
S0
B1
S1
B2
S2
B3
S3
B4
S4
B5
S5
B6
S6
B7
S7
SUB
S7
S0
M0
S1
M1
S2
M2
S3
M3
S4
M4
S5
M5
S6
M6
S7
M7
CO
V
© 2026 Daniil Khanin · khanin.info · HB-02
37
CANVAS …
13
2×
2×
S7
V
14
4b
0
A
3×
8b
DEC
A
8b
DEC
B
8b
DEC
M
A
0
A7
0
A6
0
A5
0
A4
0
A3
0
A2
1
A1
1
A0
B
0
B7
0
B6
0
B5
0
B4
0
B3
1
B2
0
B1
1
B0
1
SUB
2
M
−
V
A
0
A7
1
A6
1
A5
0
A4
0
A3
1
A2
0
A1
0
A0
B
0
B7
0
B6
0
B5
1
B4
1
B3
0
B2
1
B1
1
B0
0
SUB
127
M
−
V
A
0
A7
0
A6
0
A5
0
A4
1
A3
0
A2
1
A1
0
A0
B
0
B7
1
B6
1
B5
0
B4
0
B3
1
B2
0
B1
0
B0
1
SUB
90
M
−
V
© 2026 Daniil Khanin · khanin.info · HB-02
38
6
Bonus: decimal math
the +6 correction: 38 + 47 = 85
kh
HB-02
A
0
A7
0
A6
1
A5
1
A4
1
A3
0
A2
0
A1
0
A0
B
0
B7
1
B6
0
B5
0
B4
0
B3
1
B2
1
B1
1
B0
3
8
85
D
38 + 47 = 85
IN
9×
OUT
5×
ADDER4
2×
2
OR
2×
1
AND
1×
1
0
16×
1×
4b
0
A
3×
∞
Ctrl
+
G
BCD1
© 2026 Daniil Khanin · khanin.info · HB-02
39
CANVAS
1
Delete
0
A0
0
A1
0
A2
0
A3
0
A4
0
A5
0
A6
0
A7
0
B0
2
Delete
0
B1
0
B2
0
B3
0
B4
0
B5
0
B6
0
B7
0
SUB
S7
3
Delete
V
8b
DEC
A
8b
DEC
B
8b
DEC
M
© 2026 Daniil Khanin · khanin.info · HB-02
40
CANVAS …
4
Delete
ADDSUB8
A0
A0
A1
A1
A2
A2
A3
A3
A4
A4
A5
A5
A6
A6
A7
A7
B0
B0
B1
B1
B2
B2
B3
B3
B4
B4
B5
B5
B6
B6
B7
B7
SUB
SUB
S0
S0
S1
S1
S2
S2
S3
S3
S4
S4
S5
S5
S6
S6
S7
S7
CO
C
V
V
5
Delete
ADDSUB8
A0
GND
A1
GND
A2
GND
A3
GND
A4
GND
A5
GND
A6
GND
A7
GND
B0
S0
B1
S1
B2
S2
B3
S3
B4
S4
B5
S5
B6
S6
B7
S7
SUB
S7
S0
M0
S1
M1
S2
M2
S3
M3
S4
M4
S5
M5
S6
M6
S7
M7
CO
V
© 2026 Daniil Khanin · khanin.info · HB-02
41
BCD1
6
IN
9×
OUT
5×
A0
A1
A2
A3
B0
B1
B2
B3
CI
D0
D1
D2
D3
CO
7
ADDER4
1×
2
14×
ADDER4
A0
A0
A1
A1
A2
A2
A3
A3
B0
B0
B1
B1
B2
B2
B3
B3
CI
CI
S0
s0
S1
s1
S2
s2
S3
s3
CO
c
8
OR
2×
1
AND
1×
1
9×
OR
I0
s1
I1
s2
O0
s12
AND
I0
s3
I1
s12
O0
big
OR
I0
c
I1
big
O0
CO
9
ADDER4
1×
2
13×
ADDER4
A0
s0
A1
s1
A2
s2
A3
s3
B0
GND
B1
CO
B2
CO
B3
GND
CI
GND
S0
D0
S1
D1
S2
D2
S3
D3
CO
© 2026 Daniil Khanin · khanin.info · HB-02
42
BCD1 …
CANVAS
10
Ctrl
+
G
Library
…
Chip N
2×
Library
…
BCD1
Enter
BCD1
A0
A1
A2
A3
B0
B1
B2
B3
CI
D0
D1
D2
D3
CO
11
0
5×
5×
0
A0
0
A1
0
A2
0
A3
0
A4
12
0
5×
5×
0
A5
0
A6
0
A7
0
B0
0
B1
© 2026 Daniil Khanin · khanin.info · HB-02
43
CANVAS …
13
0
5×
5×
0
B2
0
B3
0
B4
0
B5
0
B6
14
0
1×
1×
0
B7
15
BCD1
1×
14×
BCD1
A0
A0
A1
A1
A2
A2
A3
A3
B0
B0
B1
B1
B2
B2
B3
B3
CI
GND
D0
D0
D1
D1
D2
D2
D3
D3
CO
c10
© 2026 Daniil Khanin · khanin.info · HB-02
44
CANVAS …
16
BCD1
1×
14×
BCD1
A0
A4
A1
A5
A2
A6
A3
A7
B0
B4
B1
B5
B2
B6
B3
B7
CI
c10
D0
D4
D1
D5
D2
D6
D3
D7
CO
H
17
1×
1×
H
18
4b
0
A
3×
8b
HEX
A
8b
HEX
B
8b
HEX
D
A
0
A7
0
A6
1
A5
0
A4
0
A3
0
A2
1
A1
1
A0
B
0
B7
1
B6
0
B5
0
B4
0
B3
1
B2
0
B1
1
B0
68
D
100
A
0
A7
0
A6
1
A5
1
A4
1
A3
0
A2
0
A1
0
A0
B
0
B7
1
B6
0
B5
0
B4
0
B3
1
B2
1
B1
1
B0
85
D
100
A
1
A7
0
A6
0
A5
1
A4
1
A3
0
A2
0
A1
1
A0
B
0
B7
0
B6
0
B5
0
B4
0
B3
0
B2
0
B1
1
B0
00
D
100
© 2026 Daniil Khanin · khanin.info · HB-02
45
Kit parts
how many times you place each part over all the lessons
N
11×
P
11×
VCC
1×
GND
1×
0
69×
16×
4b
0
A
15×
IN
61×
OUT
36×
488×
© 2026 Daniil Khanin · khanin.info · HB-02
46
Kit chips
you build them yourself: each one is made of the ones before
OR
12×
1
NAND
1×
1
AND
8×
1
XOR
7×
1
HA
3×
1
NOR
2×
1
NOT
2×
1
FA
4×
2
ADDER4
4×
2
ADDSUB4
3×
3
ADDSUB8
3×
4
BCD1
2×
6
© 2026 Daniil Khanin · khanin.info · HB-02
47
Done!
A
0
A7
0
A6
0
A5
0
A4
0
A3
0
A2
1
A1
1
A0
B
0
B7
0
B6
0
B5
0
B4
0
B3
1
B2
0
B1
1
B0
1
SUB
−
2
M
3 − 5 = −2
a ± calculator of 1,208 transistors
set A and B, click SUB — the display shows the magnitude, the "−" lamp the sign
© 2026 Daniil Khanin · khanin.info · HB-02
48
Copyright
© 2026 Daniil Khanin, khanin.info. All rights reserved.
These instructions, the drawings and circuits are original work.
Reprinting, publishing online, selling or passing it on to others,
in whole or in part, is prohibited without the written permission of the author.
The latest version is at khanin.info.
kh
khanin.info
HB-02
© 2026 Daniil Khanin · khanin.info · HB-02
49