Pulse Reading Logic Probe

This circuit uses LEDs to display logic states for high, low, rising pulse, and falling pulse, it is generally useful for debugging logic circuitry. This circuit can monitor TTL logic levels. TTL compatible CMOS logic families can also be monitored.

Simple logic probe uses bicolor LED

can measure high, low, and high-impedance logic states, in addition to indicating switching logic states

Introduction to a Logic Analyzer

Logic Chiptester

Pulse Reading Logic Probe

uses LEDs to display logic states for high, low, rising pulse, and falling pulse in TTL circuits

4 - Channel Digital Logic Analyzer

with 5 Channel Digital Oscilloscope by using PC Parallel Port.