Direct :: Computer Science

cipherDirect input methods.In this report I am going to explain the polar read inputmethods offset off with bar codes.A single barcode cast is genuinely s level off wholes. A building block is eitherblack or colour. A building block that is black would display as a bar. A unitthat is white would display as a space. Another room of authorship abarcode unit is 1 for a single unit black bar and 0 for a singleunit white space. For fount, the number 1 is composed of theseven units, 0011001 or space-space-bar-bar-space-space-bar.Remember, a single barcode number requires seven units.Also, on a UPC barcode the said(prenominal) poem on the left-hand side (theManufacturer Code) is coded different than the numbers on theright-hand side (Product Code). The left side numbers are actually theinverted or mirrored codes of the right side numbers, for instancewhat is a bar on the right-side, is a space on the left-side. Theright-side codes are called even parity codes because there is aneven number of black bar units. For instance the right-side 6 is101000 - 2 even-numbered black bar units. The left-side is calledodd-parity because there is an odd number of black bar units. Forinstance, the left-side 6 is 0101111 - 5 odd-numbered black barunits. Having different coded numbers for each side allows the barcodeto be s shadowerned in either direction.Direct input methods.In the second part of my report on direct input methods I am going tobe talking astir(predicate) attractionic band readers.A magnetic calamity reader, also called a magstripe reader, is ahardware device that reads the information encoded in the magneticstripe located on the back of a plastic mark. Magnetic stripe readerscan be read by a computer broadcast through a serial port, USBconnection, or keyboard wedge, and are generally categorise by theway they read a badge. For instance, insertion readers require thatthe badge be inserted into the reader and then pulled out. Swipereaders require tha t the badge promontory completely through the reader.The magnetic stripe on the back of a badge is composed of iron-basedmagnetic particles encased in plastic-like tape. Each magneticparticle in the stripe is a tiny bar magnet about 20-millionths of aninch long. When all the bar magnets are polarized in the samedirection, the magnetic stripe is blank. Information is written on thestripe by magnetizing the tiny bars in either a north or south poledirection with a special electromagnetic writer, called an encoder.The writing process, called flux reversal, causes a change in themagnetic field that can be detected by the magnetic stripe reader.