Where is the reset button on a desktop computer?

The reset button (RESET) generally refers to the button on the computer host. Its function is to press this button when the computer crashes to restore the computer to normal without shutting down.

Could you please tell me the location of the reset key on the computer keyboard (recommended learning: PHP video tutorial)

1, Generally the reset button is on the computer case, near the computer switch, and the area is smaller than the area of ​​the switch key. If you encounter a crash or other situation, you only need to press and hold it. After a period of time, you can restart the computer to help reset it;

2,You can also reset it by pressing CTRL ALT DEL on the keyboard at the same time, which is a soft reset, also called a warm boot;

3. When playing games or some software, you can use the R letter button to reset the game map or software;

Working Principle

The reset key is to start after clearing the current CPU and running data. No power outages involved.

All reset signals on the motherboard are generated by the chipset, mainly generated by the Southbridge (with a reset system controller inside) or the reset generator (74H series chip), that is to say, all the reset signals on the motherboard require Reset devices and modules are reset by the South Bridge.

If Southbridge wants to generate a reset signal or if Southbridge wants to reset other devices and modules, it must first reset itself or have a reset source.

First, after the power is turned on, the ATX power supply sends the power normal signal PWRER OK, that is, ATX PWRGD. After being shaped by the inverter HCT14, it outputs the CLROFF signal and enters the Southbridge 82371 to clear its internal registers. At the same time, the NAND gate HC132 is input. When the voltage reaches the rated value and becomes stable, the voltage control chip sends out the VRMPWRGD signal and is also input to VHC132. These two signals enter the VHC132X logic operation and the output signal is shaped by HCT14 and output to PIN10 of HCT14. South Bridge, because the gray wire of the ATX power supply will have a delay process at the moment when the power supply is working.

This delay process is equivalent to the yellow line and the red line. The delay time is 100~500ms. In other words, the gray line will have a low level to a high level at the moment when the ATX power supply is working. process of flat change. That is, a level signal that changes from 0 to 1. This instantaneously changing level signal from 0 to 1 will directly or indirectly act on the reset system controller in the south bridge, first allowing the south bridge and north bridge to reset themselves first.

When the Southbridge is reset, the reset system controller inside the Southbridge will send out the RSTDRV signal, decompose the gray line 5V signal to form ISARST, IDERSTDRV resets the ISA slot and IDE interface, and sends out the PCIRST signal , to reset the PCI slot, the reset signal of the CPU is generated by the North Bridge, and the motherboard starts to work after the reset. If it is a PG signal sent by the power manager, this signal is also a 0~1 transition process at the moment of power-on.

This signal will also repeat the above action to reset the south bridge. The south bridge will then send out other reset signals (more commonly used in notebook circuits).

When the CTRL ALT DEL key is pressed for hot start, the BIOSRST signal is sent out by 371, and the signal is input at PIN9 of U18 to trigger the reset.

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