Introduction to Computers

Intro to Computers

WHAT MAKES IT GO The design and implementation of the Lego Drag Racers will take advantage of two computer systems that will work together to provide the control necessary to design a fast car. The Power Macintosh computers provide the interface and tools necessary to control the MIT Robot Controller Boards. While the two computers differ greatly in physical appearance and user interface, underneath they are fairly similar. A computer system is made up of many components. The computer itself is usually housed inside a box or, in the case of the Robot Boards, on a single circuit board. Along with the computer itself, a computer system usually will have a monitor or some form of display, a keyboard or other input devices and a disk drive or other form of mass storage. These are all linked together to make the computer systems we that we see every day. Since computers systems can take on many different shapes and sizes, it is helpful to look inside a computer and see what makes a computer a computer and not, say, a toaster (though a toaster could have a computer inside). The heart and brains of a computer is the central processing unit, or CPU. The brain inside the CPU is the arithmetic logic unit, ALU. The ALU performs basic arithemtic and logic functions such as addition of two numbers or the AND value of two numbers. The heart in the CPU is the data path. The data path pumps commands from memory through the processor. If the command requires an arithmetic operation, it is sent to the ALU and the result is returned to the data path to be sent to the rest of the computer. The data path provides all the necessary connections with the rest of the computer and sends out control signals to parts that are not embedded into the CPU. The program that the computer is running is stored in the computer's memory. A program is nothing more than a sequence of operations for the CPU to perform. The data path reads from the memory to get the next command for the program along with any other information that the command will need. If any of the informaion changes, the data path will send the new values back to the memory. A computer system is built around a CPU and memory. The PowerMac system also contains compoments to handle graphics, printer input and output, network connections and user input through the mouse and keyboard. The CPU can get information from these devices and send informtion to them. Since the Robot Boards do not need to have a complex display and a keyboard and mouse would make them _very_ bulky, they contain a simpler set of components. In addition to the CPU and memory, they have a simple LCD display, a network port, a few knobs and buttons for user input and digital and analog input and output ports. Just as with the PowerMac, the CPU can access all these devices. So, though they look different and accecpt different type of input, the Robot Boards and PowerMacs are very similar underneath. Now let's look a little more at each of the systems and how they can be used to build fast cars.: The design and implementation of the Lego Drag Racers will take advantage of two computer systems that will work together to provide the control necessary to design a fast car. The Power Macintosh computers provide the interface and tools necessary to control the MIT Robot Controller Boards. While the two computers differ greatly in physical appearance and user interface, underneath they are fairly similar.
A computer system is made up of many components. The computer itself is usually housed inside a box or, in the case of the Robot Boards, on a single circuit board. Along with the computer itself, a computer system usually will have a monitor or some form of display, a keyboard or other input devices and a disk drive or other form of mass storage. These are all linked together to make the computer systems we that we see every day. Since computers systems can take on many different shapes and sizes, it is helpful to look inside a computer and see what makes a computer a computer and not, say, a toaster (though a toaster could have a computer inside).
The heart and brains of a computer is the central processing unit, or CPU. The brain inside the CPU is the arithmetic logic unit, ALU. The ALU performs basic arithemtic and logic functions such as addition of two numbers or the AND value of two numbers. The heart in the CPU is the data path. The data path pumps commands from memory through the processor. If the command requires an arithmetic operation, it is sent to the ALU and the result is returned to the data path to be sent to the rest of the computer. The data path provides all the necessary connections with the rest of the computer and sends out control signals to parts that are not embedded into the CPU.
The program that the computer is running is stored in the computer's memory. A program is nothing more than a sequence of operations for the CPU to perform. The data path reads from the memory to get the next command for the program along with any other information that the command will need. If any of the informaion changes, the data path will send the new values back to the memory.
A computer system is built around a CPU and memory. The PowerMac system also contains compoments to handle graphics, printer input and output, network connections and user input through the mouse and keyboard. The CPU can get information from these devices and send informtion to them.
Since the Robot Boards do not need to have a complex display and a keyboard and mouse would make them _very_ bulky, they contain a simpler set of components. In addition to the CPU and memory, they have a simple LCD display, a network port, a few knobs and buttons for user input and digital and analog input and output ports. Just as with the PowerMac, the CPU can access all these devices.
So, though they look different and accecpt different type of input, the Robot Boards and PowerMacs are very similar underneath. Now let's look a little more at each of the systems and how they can be used to build fast cars.

The PowerMac/Robot Board Connection Since the Robot Board has no keyboard, commands can not be entered directly into it. Instead, it is connected to the PowerMac and a program is run that allows the board to be controlled from the PowerMac. Commands can be sent directly to the board or programs can be downloaded into the board. Once a program is loaded onto the board, the board can be disconnected from the PowerMac and execute the program on its own. This allows the board to act as an autonomous unit that can travel with and control the car without any ties to the PowerMac. The programs that you will use on the PowerMac have already been written. But, any programs for the board you will need to write yourself. While writing large scale applications such as word processors and games is a complicated task, writing simple programs such as the ones necessary to control a car is very easy.: Since the Robot Board has no keyboard, commands can not be entered directly into it. Instead, it is connected to the PowerMac and a program is run that allows the board to be controlled from the PowerMac. Commands can be sent directly to the board or programs can be downloaded into the board. Once a program is loaded onto the board, the board can be disconnected from the PowerMac and execute the program on its own. This allows the board to act as an autonomous unit that can travel with and control the car without any ties to the PowerMac.
The programs that you will use on the PowerMac have already been written. But, any programs for the board you will need to write yourself. While writing large scale applications such as word processors and games is a complicated task, writing simple programs such as the ones necessary to control a car is very easy.