XTAL2 18

XTAL1 19

ALE 30

EA 31

PSEN 29

RST 9

P0.0/AD039

P0.1/AD138

P0.2/AD237

P0.3/AD336

P0.4/AD435

P0.5/AD534

P0.6/AD633

P0.7/AD732

P1.0 1

P1.1 2

P1.2 3

P1.3 4

P1.4 5

P1.5 6

P1.6 7

P1.7 8

P3.0/RXD10

P3.1/TXD11

P3.2/INT012

P3.3/INT113

P3.4/T014

P3.7/RD17 P3.6/WR16 P3.5/T115

P2.7/A1528

P2.0/A821

P2.1/A922

P2.2/A1023

P2.3/A1124

P2.4/A1225

P2.5/A1326

P2.6/A1427

U?

AT89C51

D7

14

D6

13

D5

12

D4

11

D3

10

D2

9

D1

8

D0

7

E6

RW

5

RS

4

VS

S1

VDD

2V

EE

3

16 X 2 ALPHANUMERIC LCD

X

C1

30pF

C2

30pF

+5 V

+5V

C3

10u

R1

10k

Q2N2222A

R21k

CIRCUIT DIAGRAM

+15V

TX

3

21

411

A:A

LM324

RX

R42M

C4

3.3nF

R682k

R52M

C5

3.3nF

R710k 5

67

411

A:B

LM324

10

98

411

A:C

LM324 R833k

D1

1N4148

D21N4148

R9100k

C6

2.2nF

12

1314

411

A:D

RV1RES-VAR

R1010k

+5V

-15V

+15V

3 2

N:A

5 4

N:B

7 6

N:C

9 10

N:DCD4049

11 12

N:E

14 15

N:F

R1110k

R310k