The oscilloscope is one of the most useful helpers in the electronics workshop, when repairing historical computers or when reverse engineering circuits (i.e. analyzing unknown systems). It used to be a purchase that hobbyists had to save on for a long time.
Today there are good digital oscilloscopes from well-known manufacturers for little money. Unfortunately, to get started, it is not enough to read the enclosed manual – this mainly explains the arrangement of the buttons, but requires a lot of knowledge about how to use them. The manual often does not reveal why an oscilloscope is useful in practice and how to get useful results. It is helpful to know the basic functional principle: The oscilloscope shows measured voltages over time. So far, so unspectacular.
This article uses a clear example to show when these voltages reveal a lot about the circuit: The aim is to examine the signal from an old PS / 2 keyboard. Many certainly still have one in their old equipment box. The complexity of PS / 2 is manageable, making it ideal for initial success in analysis. For beginners, we will first explain how to start up and set up an oscilloscope – if you, as an experienced user, want to reverse engineer PS / 2 directly, continue reading in the “Keyboard Analysis” section.
- Access to all heise + content
- exclusive tests, advice & background: independent, critically well-founded
- Read c’t, iX, MIT Technology Review, Mac & i, Make, c’t photography directly in your browser
- register once – read on all devices – can be canceled monthly
- first month free, thereafter € 12.95 per month
- Weekly newsletter with personal reading recommendations from the editor-in-chief
Start FREE month
Start your FREE month now
Already subscribed to heise +?
Sign up and read
Register now and read articles right away
More information about heise +