Quality Assurance Consulting: Printer Overview
Here are the main modern printing technologies:
Matrix printers print using metal pins arranged in several rows on the printhead. When the pin extends from the head and strikes the surface of the paper through a strip of the ink soaked cloth, it makes impression on the paper as a small dot. If all the pins are pulled out simultaneously, a vertical dash about three millimeters long is obtained. The printer prints the letter in parts: the head is fed to its left edge, the necessary pins are put out, printing the first part of the letter, then the head is shifted to the right, the next part of the letter is printed in the same way, and so on. Typically, the matrix printers have 9 or 24 pins, but there are other options as well. There are also such printers, in which the head, studded with pins, spans the full width of the line, so it does not move to the right and to the left, but prints the entire line with a single punch. The letter printed by the matrix printer looks granular, and distinct points are clearly visible in it. It is especially noticeable in 9-pin printers in draft mode (at the highest speed). With the development of matrix printing technology, manufacturers have learned to produce more advanced devices, which heads move fast enough, while the points are located so close to each other that they practically merge. As a result, they can print graphics at higher resolution, and produce the text of much better quality. Quality assurance consulting is a great way to obtain optimal software testing and quality assurance solutions.
Inkjet printers squirt ink on the paper, forming small dots. Their main advantages are the quietness and high quality of printing.
Page printers do not print characters and lines, but complete pages. By printing technology, they are divided into laser, LED and thermal ones.
Parallel printers are more common in Microsoft and Amiga worlds. Parallel connection gets information transferred to the printer much faster than any other connection, because 8 bits of information are transmitted at once – across eight parallel wires. By the way, software qa outsourcing gives you the chance to reduce costs of the product development while boosting return on investment.
When the printer is connected in series, the information bits are transmitted one at a time. This kind of connection is somewhat more complicated, since it requires more complex protocols, in particular, determining the availability of the device and designating the beginning and end of the bit sequence.
The main thing that you need to know to test a program that supports both parallel and serial printers is that you will have to separately test both types of devices. List of software testing companies can be useful for you to find a good testing specialist within shortest time possible.