[Robert Morrison] had an ancient HP 545A logic probe, which was great for debugging SMT projects. The only problem was that being 45 years old, it wasn’t quite up to scratch when it came to debugging ...

In the mid-1970s, HP developed a set of three handheld probes; a logic probe (HP 545A), a current pulser (HP 546A), and a current tracer (HP 547A). These were replaced later with the updated HP10525T ...

A recent Design Idea in EDN magazine, “Logic Probe Uses Six Transistors” caught my eye because I had just pulled out an old logic probe purchased many years ago. It seems logic probes have fallen into ...