Electronic computers are made of logic circuits. The aim of this chapter is to explain how the basic computer functions of arithmetic and storage can be done using these circuits. It culminates in a brief discussion of the ADD and MOV commands.

The most basic logic circuits are called gates. Gates are controller circuits. The simplest logic gate is the NOT gate. In the next section, it is shown how a NOT gate can control a flashlight.

The NOT Gate

The simple flashlight circuit shown, in Figure 3-1, is controlled by the switch at the top, which is shown in the open position. The negative end of the battery is connected directly to the bulb, but the positive end is only connected to the bulb by way of the switch. ...

Get Linux Assembly Language Programming now with the O’Reilly learning platform.

O’Reilly members experience live online training, plus books, videos, and digital content from nearly 200 publishers.