Machine Unit

A cartoon showing the evolution of some quantity (blue) within the machine units (green shaded area), going into overload (red shaded area). As soon as a value reaches overload, it is clipped, the LED goes on and the furthermore computation is most likely wrong! There is a small tolerance gap ov 2V above the machine units.

Machine units are the conventions how to represent numbers on analog computers such as The Analog Thing (THAT). In digital context, these are typically called logic levels.

THAT works with logical one represented by +10V and logical minus one represented by -10V. It is helpful to thing in all quantities being bracketed within the real number interval [-1,+1]. In electrical engineering, this is called bounded in bounded out systems, as any computation has to produce results within this domain in order to be meaningful on an analog computer. These machine units are bipolar, this is in contrast to unipolar units such as 0V for logical zero and +5V for logical one in the digital TTL logic system.

Levels for output

When it comes to output which can be displayed on oscilloscopes, level shifting may apply. For instance, the Soundcard output operates with roughly ±1V.