If the resolution of the video display is 640 pixels horizontally by 480 pixels vertically, the total amount of memory required is 921,600 bytes, or nearly a megabyte. The number of bits per pixel is sometimes referred to as the color depth or color resolution.
Digital computer memory stores only bits, so anything that we want to work with on the computer must be stored in the form of bits.
Hangi tür kitapları seviyorsun?
🔎 Polisiye
💕 Romantik
🚀 Bilim Kurgu
🏰 Fantastik
📖 Klasik
🧠 Kişisel Gelişim
🏛️ Tarih
😱 Gerilim
For example, TXT indicates a text file (that is, a file containing only ASCII codes), and COM (which is short for command ) indicates a file containing 8080 machine-code instructions—a program.
Sometimes people squabble over whether programming is an art or a science. On the one hand, you have college curricula in Computer Science, and on the other hand, you have books such as Donald Knuth's famous The Art of Computer Programming series. "Rather," wrote physicist Richard Feynman, "computer science is like engineering—it is all about getting something to do something."... Occasionally, a programming problem incites flashes of creativity and insight, and that's the "art" part. But programming is mostly a designing and building process not unlike erecting a bridge.
The computer that we've built is constructed from relays, wires, switches, and lightbulbs. All of these things are "hardware". In contrast, the instructions and other numbers that we enter into memory are called "software". It's "soft" because it can be changed much more easily than the hardware can.
Generally, in computer programs, we can distinguish between code (which refers to the instructions themselves) and data, which are the numbers that the code manipulates.
While the two-dimensional image of a video display or a television might seem complex, the image is actually composed of a single continuous beam of light that sweeps across the screen very rapidly. The beam begins in the upper left corner and moves across the screen to the right, whereupon it zips back to the left to begin the second line. Each horizontal line is known as a "scan line". The movement back to the beginning of each of these lines is known as the "horizontal retrace". When the beam finishes the bottom line, it zips from the lower right corner of the screen to the upper left corner (the vertical retrace) and the process begins again. For American television signals this happens 60 times a second, which is known as the "field rate". It's fast enough so that the image doesn't appear to be flickering.