Last Sync: 2022-09-07 20:00:05

Hardware/Logic_Gates/Creating_memory_with_NAND.md

@@ -0,0 +1,10 @@
+---
+title: Creating memory with NAND gates
+categories:
+  - Computer Architecture
+  - Electronics
+  - Hardware
+tags: [logic-gates, binary]
+---
+
+# Creating memory with NAND gates

Hardware/Logic_Gates/Logic_gates.md

@@ -7,11 +7,12 @@ tags: [logic-gates, binary]
 ---
 
 # Logic gates
+
 > [A logic gate consists in] three connections where there may or may not be some electricity. Two of those connections are places where electricity may be put into the device, and the third connection is a place where electricity may come out of the device. (Scott, 2009 p.21)
 
-Logic gates are the basic building blocks of digital computing. **A logic gate is an electrical circuit that has one or more than one input and only one output.** The input controls the output and the logic determining which types of input (on/off) lead to specific outputs (on/off) is identical to the truth-conditions of the  [Boolean connectives](../../Logic/Truth-functional_connectives.md) specifiable in terms of [truth-tables](../../Logic/Truth-tables.md).
+Logic gates are the basic building blocks of digital computing. **A logic gate is an electrical circuit that has one or more than one input and only one output.** The input controls the output and the logic determining which types of input (on/off) lead to specific outputs (on/off) is identical to the truth-conditions of the [Boolean connectives](../../Logic/Truth-functional_connectives.md) specifiable in terms of [truth-tables](../../Logic/Truth-tables.md).
 
-Physically, what 'travels through' the gates is electrical current and what constitutes the 'gate' is a transistor responding to the current. But on a more abstract level it is bits that go into the gate and bits which come out: binary information that may be either 1 or 0. 
+Physically, what 'travels through' the gates is electrical current and what constitutes the 'gate' is a transistor responding to the current. At the next level of abstraction it is bits that go into the gate and bits which come out: binary information that may be either 1 or 0.
 
 ## References
 

Hardware/Logic_Gates/Nand_gate.md

@@ -10,28 +10,17 @@ tags: [logic-gates, binary]
 
 A NAND gate is a logic gate that inverts the truth-conditions for `AND`.
 
-A real-life circuit showing two switches corresponding to two transistors which control the LED light: 
-
-![NAND_from_transitors.png](../../img/NAND_from_transitors.png)
-
-In this circuit, there are two transistors, each connected to a switch. The switches control the LED light. So the switches are the input and the LED is the output.
-
-For clarity, we are not going to draw both transistors, we will simplify the diagram with a symbol for them which stands for the NAND gate:
-
-![NAND.png](../../img/NAND.png)
+Diagram representing NAND gate:
 
+<img src="/home/thomas/repos/computer_science/img/NAND.png" width="180" />
 
 The diagram below shows how the circuit models the truth conditions for `NAND`
 
-Diagram representing NAND gate:
-
-![NAND.gif](../../img/NAND.gif)
-
+<img src="/home/thomas/repos/computer_science/img/NAND.gif" width="400" />
 * When both switches are off (corresponding to `false` `false`) the output is on (the bulb lights up).
 * If either one of the switches are on, the output remains on (corresponding to `true` `false` or `false` `true` )
 * It is only when both switches are on, that the output is off (corresponding to `true` `true` )
 
-
 This is the exact opposite to the truth-conditions for AND.
 
 ## Transliterating the logic truth-table to the switch behaviour
@@ -54,6 +43,7 @@ t    f     f
 f    t     f
 f    f     f
 ```
+
 We can see that it inverts the value of AND.
 
 ## Significance of the NAND gate: functional completeness