Subtitles of the Movie

I want to talk about a bus just a second. I've mentioned them and they've been in diagrams so far in the course, but I want to make sure that I don't just assume you know what the bus is. A bus is simply a,,, pathway from one piece of equipment on the motherboard to another. And for example you have the External Data Bus, and this connects the processor to the external parts of the processor also called the Front Side Bus, and this is the bus that actually connects to the processor. Now there's another bus in there that ah connects and sometimes you'll call it, you'll year it called the Backside Bus, and all sorts of things. But this allows the processor to speak to the RAM, okay. And this goes through a little station called the MCC, or the Memory Controller Chip and there is a bus between the memory controller chip, ah, and the CPU and this lets the CPU ask for things in RAM, the MCC converts that, goes across its bus out to the RAM and grabs the information. Now what's the most important thing to understand about buses is that these things have grown in size since the first PC. Ah, the original IBM PC had an 8-bit data bus and if you remember from our ah examples about binary earlier, 8-bits meant eight pieces of information and ah nowadays we have 32-bit buses, so 32 bits of information as opposed to eight, it's a tremendous amount of information can be passed across that bus. You also see these buses getting faster. You now hear of like, ah, 800 megahertz front side bus speed. Well, what's happening is, is the front side bus isn't actually running at 800 megahertz but there's a multiplier being applied to it, but it's functioning as if it was 800 megahertz because it may be actually running at 100 megahertz but they're putting four times as much information into a single clock ah tick. So, anyway, buses can get ah, the whole process can get ah somewhat confusing and they won't go that deep in A Plus but just understand that a bus is simply a pathway between the various components that are on the motherboard.