"Coding-the language hidden behind the computer"--reading Notes (iv): logic

10. Logic & Switches

1) Bit in logic is also important, true or false can be expressed as 1 and 0

2) in Boolean algebra, operands are not numbers but classes, and a class is a group of Things (collections). In Boolean algebra, the calculation of a class is calculated using the intersection, the sum set,1 representing the complete, and 0 for the empty .

3) Boolean algebra mapping to the representation in the circuit: and: concatenation; OR: Parallel

4) The principle of using the switch in the circuit, you can create the Telegraph, which can evolve to create a computer

11. Door

1) in logic, the logic gate works very simply---let the current pass through or stop the passage.

2) Network: Previously referred to as a collection of multiple switches, now refers to the connection between computers.

3) Shannon: Realize that Boolean expressions can be implemented in the circuit

4) Logic gate: The switch is an input device, and the input is the information of how the control circuit works. relays , like switches, can perform simple logic tasks in series parallel circuits, a combination of which is called a logic gate.

The switch is manual, and the relay is controlled by the current rather than by the manual (and can also be controlled by the relay).

5) with the Door (and): Just like the two switches in series, the series of two relays is called a with the door.

6) or the door (or): (2 relays in parallel) only one input terminal is 1, the output is 1; All 0 o'clock output is 0;

7) or non-gate nor: (contrary to or); vs. Non-gate NAND: (contrary to and)

8) The reverse (not the logic gate), you can convert the low level to high (that is, 0 becomes 1)

9) The buffer (similar to the symbol of the inverter without loops) inputs and outputs are the same, delaying a signal. This is because the relay takes a little bit of time (a few seconds) to be triggered.

"Coding-the language hidden behind the computer"--reading Notes (iv): logic