Reverse engineering is the process of discovering the technological principles of a device or object or system through analysis of its structure, function and operation. It often involves taking something apart (e.g. a mechanical device, an electronic component, a software program), and analysing its workings in detail. The purpose is usually to try to make a new device or program that does the same thing without copying anything from the original. In practice, reverse engineering can take one of two forms; either the random hardware approach of ‘circuit bending’ or the structured hardware approach of ‘hardware hacking’.
Circuit-bending ‘Circuit-bending’ as a practice generally means a creative application of short circuits to electronic devices. The intention is to bring about aesthetic improvements in a particular device’s output, and it is almost always done with devices that are cheap and generate audio signals. There is some circuit-bending done with devices that generate video, but not much as the price of such devices is generally too high to make circuit-bending’s random (and often destructive) results worthwhile. The circuit-bending method tends to follow four basic steps: 1. Simple tools (such as crocodile clips) are used to experiment on a device’s circuit board; in some instances this will create short circuits. 2. If any short circuit is of interest, a record is kept of where it occurred. 3. Once there are enough short circuits of interest, they are soldered in place with wire to make them permanent, adding in some switches and potentiometers for variation. 4. The switches and potentiometers are then mounted in the body of the device Other techniques such as replacing resistors with other resistors of different values or variable resistors are used. This works with both older (and rarer) analogue devices in which a resistor might control the frequency of an oscillator and with digital devices where a resistor often sets the playback speed of samples. Simple interface modification is another circuit-bending practice, replacing factory switches with other types of switches or removing the electronic guts of a toy and installing the whole thing in a new housing. Sometimes just simply re-working a device’s interface can bring about a completely new way of playing it. Health and Safety Warning: Circuit-bending is only done on low-voltage battery-operated devices for safety reasons.