If one wants to find out a bit more about the details of a computer, the best thing to do is to start with the two terms, hardware and software. As the name suggests, hardware is hard, something that is tangible and can be felt, software, on the other hand, is simply a set of virtual instructions or directives, which are fed into the computer's processor, which can then carry out the said intructions.

To put the hardware into some sort of order, it's divided into input, processing and output. The keyboard and mouse eg., obviously belong to the input devices. A printer, clearly to the output. Now, what about the touchscreen? It's not that simple, also as far as the operation is concerned. In the automobile we have become accustomed to see control devices, microprocessors and one-chip computers as part of the processing. Indeed, the latter, e.g., may be a CAN-Bus with a transmitter, which would put it in the category of input/output devices.

It's easier for the technician. For him, a sensor is an input-, and an actuator is an output device. It is still fairly rare, that a single component does both, e.g, like the spark plug, which simultaneously generates an ignition-spark and also allows the measuring of the ion-flow. The important thing is, the work of the sensors is picked up by the workshop testing-device through the evaluation of the data, the work of the actuators however, through the actuator control diagnosis.

Another distinction is made between Random Access Memory and Read Only Memory. The former is read- and writeable, the latter is only readable. That sounds easy, indeed, there are also ROMs, which under certain circumstances, are also writeable. Chiptuning fans can tell you a thing or two about that. 'Flashing' the memory, means the changing of what is actually unchangeable.

What we've still got, is the Operating System, which should contain the programms, which make the computer function in the first place. After that, the user-software would be installed. If you assume Windows as the beginning and Microsoft Word as the end, then it would seem that there are special Operating System accesses, which are hidden from other software.

An overall picture of the user-software available for the automobile sector is hardly possible. We can only pick out small examples. E.g., the link-up between a filling station and their head office to coordinate possible price increases, or the oscillogramm with the injection signal. An expert can also only estimate the accident damage nowadays, with the help of a computer. 03/12