Without Direct Memory Access, when the CPU uses programmed inputs/outputs, it is usually fully occupied during the entire read or write operation, so it cannot perform other tasks.
#HOW DOES LONG PATH TOOL WORK WINDOWS#
This entire amazing and complicated transaction happens using billions of dollars worth of computers, switches, wire and fiber-optic cable, all in a blink of an eye.Tip: You may be interested in this post - 8 Useful Solutions to Fix Your CPU 100% in Windows 10. Your long-distance carrier's switches route the call to the local carrier for your friend, and the local carrier completes the call to your friend.
#HOW DOES LONG PATH TOOL WORK CODE#
(When you switch long-distance carriers, this PIC code is what changes.) The switch looks up the PIC code for your number and then connects to a long-distance switch for your long-distance carrier. The database contains what's called a PIC code (Primary Interchange Carrier code), which indicates which long-distance carrier you have chosen. Today, when you place a long-distance call, the switch in the local office accesses a database that contains a record for each phone number connected to the switch. Instead, there are many different long-distance and local carriers. The phone company is no longer a monopoly.The difference in cost between "a pair of copper wires carrying a single conversation" and "a single fiber carrying thousands and thousands of conversations" is phenomenal. Your voice (along with thousands of others) becomes a stream of bytes flowing on a fiber-optic line between offices. Instead, a fiber-optic line carries a digitized version of your voice (see How Analog and Digital Recording Works for a description). Physical wires no longer connect the offices together for each phone call.In today's world, there are two things that make the system more interesting: The computers in each office would pass the number along as digital data via data lines connected between the switches. Then the local office would connect you to your friend. The 555 told the long-distance office in New York which local office to connect to. The 212 told the long-distance switch which long-distance line to grab. If, from California, you dialed 1-21 - a New York number - the 1 identified it as a long-distance call, telling the local switch to connect to a long-distance switch. Physical wires still connected you to the receiving party on each call, but the computer connected them together at each office. The computers could create the connections and the billing records just like a human operator. To make a long-distance call, you would dial "O" to speak to a human being, and the human being would connect the call through the long-distance offices as before.Ĭomputers allowed for the replacement of the long-distance operators with computerized switches. When you placed a local call, the switch would connect you. The first act of automation was to replace Mabel with a mechanical switch. The long distance operator kept track of the length of your call and created a billing record. Your call was patched together with direct, physical wires going from one office to the next. Then Mabel would connect you to the long-distance line, and you would be able to have your conversation.Īs you can see, this system is still remarkably simple.That operator would make a connection to your friend.Eventually, Mabel would be able to talk to the operator in the central office for the town that your friend lives in.Mabel would tell the long-distance operator the number, and she would connect to another office.The long-distance operator would connect Mabel to another long-distance office - the office for the area code of your friend.She would speak to the operator in the long-distance office.Mabel would connect to one of the lines going to the long-distance office.
0 kommentar(er)
