Direct :: Computer Science

DirectDirect stimulation methods.In this report I am going to explain the disparate direct inputmethods commencement off with cake codes.A single measuring rodcode number is actually seven units. A unit is either foreboding(a) or white. A unit that is black would display as a bar. A unitthat is white would display as a space. Another way of writing abarcode unit is 1 for a single unit black bar and 0 for a singleunit white space. For instance, 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 same numbers on the left-hand stance (the manufacturer 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 scanned in either direction.Direct input methods.In the second part of my report on direct input methods I am going tobe talking about magnetic stripe usherers.A magnetic stripe reader, also called a magstripe reader, is a ironware device that reads the information encoded in the magneticstripe located on the back of a plastic badge. Magnetic stripe readerscan be read by a computer program through a serial port, USBconnection, or keyboard wedge, and are generally categorized by theway they read a badge. For instance, insertion readers require thatthe badge be inserted into the reader and then pulled out. Swipereaders require that the badge pass completely thr ough 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 state of flux reversal, causes a change in themagnetic field that can be detected by the magnetic stripe reader.