How are instructed turned into electrical signals?

[hobz]

I was wondering how and when an instruction is turned into Volts.

 

suppose I have:

add ax,bx

 

Now that is compiled into some bit sequence like 01010111 (e.g.).

 

How do these bit get turned into 0 V and 5 V? What component is responsible for this?

 

Thanks.

Edited December 17, 2009 by hobz

[JillSwift]

The keyboard, most of the time.

 

The CPU instructions themselves exist as bits during execution, stored like any other data in memory.

The source of those instructions came from a programmer tapping away at a keyboard - and that process is simply monitoring the opening and closing of switches (the keys) and interpret them as which key was pressed, and store the associated character in memory.

Those character codes are then converted into CPU instructions via a previous set of CPU instructions (the compiler).

 

The original CPU instructions to make all this come to pass were probably also entered via a keyboard, with the interpretation of those keystrokes handled by a hardware interpreter of a sort no longer in use.

 

HTH

[bascule]

How do these bit get turned into 0 V and 5 V? What component is responsible for this?

 

A compiled program is stored on disk.

 

When you launch a program, the CPU instructs your hard disk controller to retrieve the program and store it in RAM. The hard disk controller then talks to a microcontroller on your hard drive, which moves the drive head back and forth and reads the program off of disk into your hard drive's cache. The program is then transferred from your hard drive's cache into the system RAM by the hard disk controller.

 

Once the program is in RAM, the CPU will then load instructions from it into its registers and execute them.

 

Every single step of this process involves electrical signaling between components.

[hobz]

Pretty good explanations. Thanks!

 

I suppose that punch cards work in a similar way, by converting the holes to ones or zeros in some process.

[JillSwift]

Pretty good explanations. Thanks!

 

I suppose that punch cards work in a similar way, by converting the holes to ones or zeros in some process.

Yep, spot on.

[Chriton]

I was wondering how and when an instruction is turned into Volts.

 

suppose I have:

add ax,bx

 

Now that is compiled into some bit sequence like 01010111 (e.g.).

 

How do these bit get turned into 0 V and 5 V? What component is responsible for this?

 

Thanks.

 

Easy...0=No Volts 1=5 volts, it is just a switch to calculate what signal is sent where.

 

A computer is just an enhanced Calculator, It can only calculate the numbers put in.

 

The processor decides where the signal goes by reading the inital input OFF and ON switches, the Grapich are also read by Pixel on and Pixel off.

 

Babbage was the Discover of Binary as he realised that a sequence of lights being OFF or ON could be used to do calculations, and that is basically what a Computer dose.