Difference between revisions of "Gate"
From Computer History Wiki
m (+cat) |
m (typo) |
||
| Line 7: | Line 7: | ||
* OR | * OR | ||
* NAND (AND with inverted output) | * NAND (AND with inverted output) | ||
| − | * | + | * NOR (similar) |
The first gates were built out of [[vacuum tube]]s; these were replaced with discrete [[transistor]]s. Larger logical elements, starting with [[flip-flop]]s, but including such things as [[counter]]s, [[shift register]]s, [[multiplexer]]s, etc, were built out of gates. | The first gates were built out of [[vacuum tube]]s; these were replaced with discrete [[transistor]]s. Larger logical elements, starting with [[flip-flop]]s, but including such things as [[counter]]s, [[shift register]]s, [[multiplexer]]s, etc, were built out of gates. | ||
Latest revision as of 13:06, 14 May 2021
A gate is the lowest level logical (as opposed to analog) circuit element. It takes a limited number of inputs, performs some operation on them, and produces an output (sometimes, the output and its negation).
Typical gates are:
- NOT (also known as an 'inverter')
- AND
- OR
- NAND (AND with inverted output)
- NOR (similar)
The first gates were built out of vacuum tubes; these were replaced with discrete transistors. Larger logical elements, starting with flip-flops, but including such things as counters, shift registers, multiplexers, etc, were built out of gates.
The next step was the creation of integrated circuits; the first ones each held a number of gates, but quickly the larger elements were then built as ICs too.
