Source: Konrad Zuse Internet Archive
Computers have become an essential part of our lives and significantly influence our daily routine. From using them at work, to gaming at home, to listening to music, writing messages and social media on our cell phones. We already took a closer look at how our computers work today and what lies behind them in our last article “From Click to Display, This is How Computers Calculate”. But how did this journey begin?
The Birth of the Computer
When we think of the beginnings of computer technology, we often think of home computers such as Apple’s Macintosh from 1984, which was known for the first commercially available graphical user interface and the macOS operating system. Another example is MS-DOS from Microsoft, which was introduced in 1981 and was controlled via the command line. Others may even remember the old consoles and arcade machines from the 1970s.
However, the first computers, whose origins go back a few years further, did not even have an operating system and were very different from today’s devices – they were more reminiscent of massive server cabinets. This only changed with the use of transistors and the invention of microprocessors in the early 1970s.
In the beginning, functions similar to those of today’s pocket calculators were desired. Even though there had long been tools for mathematical calculations such as the abacus, the slide rule and even the mechanical calculating machine, the goal was to streamline this process and to make it completely automated. In this context, Konrad Zuse once said humorously: “I’m too lazy to calculate.”
The idea of a freely programmable computer is attributed to the British mathematician Charles Babbage. He is said to have had the idea as early as 1823 but was unable to implement it due to the mechanical limitations of his time.
Shortly before the start of the Second World War, several people independently took up the idea again. The first completion of such a machine, namely the Z1, is attributed to Konrad Zuse in 1938. He completed the successors Z2 and Z3 in 1939 and 1941 respectively.
The Z1: The First Mechanical Attempt
Zuse built the Z1 from thin metal sheets and rods, so it was entirely mechanical in design. The only electrical part of this machine was the built-in electric vacuum cleaner motor, which was used to control the mechanics. Similar to today’s computers, the Z1 already had a control and computing unit, RAM, a mass memory and input and output units.
This did not change with the Z2 and Z3. It was also possible to program all three machines.
However, due to the purely mechanical components, this first design was not only very slow – it could only perform one operation per second (1 Hertz) – but also prone to errors. This was due to the precision required, which Zuse could not achieve with his hand-made components. As a result, although the Z1 was able to solve calculations correctly, its unreliability made it unusable in practice.
The Z2: A Proof of Concept for Relay Technology
Source: [pixabay]
Relays are electromagnetic switches that are operated by an electric current. There is a coil in a relay; when current flows through this coil, a magnetic field is created. This attracts an armature which, through its movement, presses two contacts together and closes the switch. In this way, a larger circuit can be controlled with a small control current. In addition, the implementation of the binary system is simplified: when no current is flowing – 0, when current is flowing – 1.
Thanks to the use of relays, the Z2 not only worked faster, but was also significantly more reliable than its predecessor, as the number of moving parts was reduced.
But Zuse didn’t integrate all the functions he envisioned for his build since the Z2 was mainly as proof of concept to test relays as a solution. So in reality the machine was never used.
The Z3: The First Fully Programmable Computer
In the subsequent Z3, Zuse followed the logic of the Z1, but used 2000 relays, 600 for the arithmetic unit and 1400 for the memory, and optimized its design. He used even fewer mechanical parts and relied more heavily on electromagnetic solutions such as relays. This again increased both the performance (5.3 Hertz) and the reliability of the Z3. In comparison, today’s CPUs have a clock speed of several gigahertz – so they are more than 100 million times faster. The biggest differences between the Z2 and Z3 were that the Z3 was fully programmable, worked with a fully automated program flow, calculated with floating point numbers and could calculate square roots.
Many of these concepts are still the basis of our modern computers and can be traced back to Zuse’s design.
If you are interested in this topic and would like to learn more about the structure and functions of individual components, look forward to the next article.
Responsible for the content of this article is Marc Weerts.
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