INSTITUTE OF BUSINESS ADMINISTRATION, KARACHI
Digital Logic Design (CSE-241)
Laboratory Manual
LAB # 4
INTRODUCTION TO IDL-400 LOGIC TRAINER
Objective

To get acquainted with the Analog/Digital Training System.
o To study the basic logic gates: AND, OR, INVERT, NAND, NOR, and XOR.
o To understand formulation of Boolean function and truth table for logic circuits.
Equipment:
1. Logic Probe
3. Digital Logic Trainer IDL-400
Components:
1. Three- quad 2-input OR gate, 74LS32
2. One- quad 2-input XOR gate, 74LS86
3. One- Quadruple 2-input NAND gate,
74LS00
4. One- Quadruple 2-input NOR gate,
74LS02
5. One Hex Inverters gate, 74LS04
6. One- Quadruple 2-input AND gate,
74LS08
Analog/Digital Training System:
Useful features include:
1. DC Power Supply (with short circuit indication)
2. Breadboard:
3. Pulse Generator:
4. Basic Logic Gates
5. LEDs
6. Input Switches with de-bounce
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The Breadboard
The breadboard consists of two terminal strips and two bus strips (often broken in the centre). Each bus
strip has two rows of contacts. Each of the two rows of contacts is node. That is, each contact along a
row on a bus strip is connected together (inside the breadboard). Bus strips are used primarily for power
supply connections, but are also used for any node requiring a large number of connections. You will
build your circuits on the terminal strips by inserting the leads of circuit components into the contact
receptacles and making connections with 22-26 gauge wire. There are wire cutter/strippers and a spool
of wire in the lab. It is a good practice to wire +5V and 0V power supply connections to separate bus
strips. The 5V supply MUST NOT BE EXCEEDED since this will damage the ICs (Integrated circuits) used
during the experiments. Incorrect connection of power to the ICs could result in them exploding or
becoming very hot.
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TASK 1:
I.
II.
III.
IV.
V.
VI.
Construct a circuit on the trainer which implements the function C=A.B as shown in
figure below.
Verify the truth table for the above mentioned function for all possible input
combinations.
You could use the LED outputs available to observe the output.
Make additions to your current circuit so that it represents the function E=A.B.C.D
Use LED outputs to observe output at every gate used.
Record the observations in a new Table.
VSS S2
5V
X1
U1A
VSS
5V
S5
2.5 V
A
B
C=A.B
1
1
1
1
0
0
0
1
0
0
0
0
74LS08D
Table 1.1
TASK 2:
I.
Connect two of the NOR gates as shown in the figure below and verify operation as an OR
function using the truth table given below.
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A
B
C=A+B
1
1
1
1
0
1
0
1
1
0
0
0
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II.
Connect the three input on one of the gates together so it can be used as an inverter. Verify that
the gate now operates as an inverter by applying the two possible input combinations.
VCC
X2
5V
2.5 V
U1B
A1
74LS10D
A
B=~A
0
1
1
0
TASK 3:
I.
Construct the circuits to prove the basic working of an XOR gate will the truth table provided
below.
VCC
5V
X1
S1
2.5 V
U1A
S2
74LS86D
A
B
C=A⊕B
1
1
0
1
0
1
0
1
1
0
0
0
Task 4:
I.
II.
Construct a circuit for the following expression.
a. (A+B).(C⊕D)
Also construct the truth table.
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