Input-Output Systems

A CRT (Cathode Ray Tube) monitor consists of several key components: the phosphor screen that glows when struck by electrons, the shadow mask that ensures electrons hit the correct phosphor dots, and the electron gun that emits the electron beam. Gas plasma is an entirely different display technology used in flat-panel displays, not in CRT monitors. This is a knowledge-based question about CRT monitor architecture.

Optical disks (CDs, DVDs) store data by burning microscopic pits onto a circular disk using laser technology. This is fundamentally different from magnetic storage (floppy disks, tapes) or punch cards. Option D correctly identifies optical disks as using this pit-burning method.

Dvorak is the fastest keyboard.

A touch pad (touchscreen) uses switch contacts placed under a plastic pad that can be inscribed with symbols. When pressure is applied to specific areas, the underlying contacts make connection, registering input. This is characteristic of resistive touch technology where two conductive layers with contacts are separated by a spacer. Punched cards use holes, soft keyboards are virtual interfaces, and mice use optical/trackball sensors.

Baudot code is a character set that uses 5 bits per character, allowing for 2^5 = 32 combinations. However, with the use of shift characters (Letters and Figures), it can represent 58 distinct symbols.

A standard Hollerith card has 80 columns and 12 rows. If organized into nibbles (4 bits), the capacity calculation depends on the specific encoding, but 240 is the accepted answer in this context.

Punched cards, particularly those used by IBM, were based on the Hollerith code, which was developed by Herman Hollerith for the 1890 US Census.

Flat panel displays, such as LCDs and OLEDs, utilize solid-state technology to manipulate light and display images, replacing bulky cathode ray tubes.

Electrostatic plotters work by placing dots on paper to create an image. Therefore, the input data must be in a raster format, which consists of a grid of pixels or dots.

Holographs (or more accurately, barcode scanners/readers) are used to sense and decode the information contained in bar codes for inventory management.

A daisy wheel printer uses a wheel with characters at the end of spokes. It strikes an inked ribbon against the paper, making it an impact printer.

Laser printers use toner and laser technology to produce high-resolution, sharp text and graphics. Other options like dot matrix or ink jet generally offer lower precision or slower output for high-quality graphics.

Plotter accuracy is defined by its ability to return to a specific point (repeatability) and the smallest increment it can move (resolution). These two factors determine the precision of the output.

A dumb terminal consists primarily of an input device (keyboard) and an output device (screen). It lacks its own CPU or storage, relying entirely on a host computer for processing.

Parallel printers historically utilized the Centronics interface standard, which involved specific handshake signals to manage data flow. These elements are standard components of parallel printer communication.

Resolution is determined by the number of pixels or lines a display can render, which is influenced by bandwidth and scan rates. Screen size refers to physical dimensions and does not inherently dictate the resolution.

Optical Character Recognition (OCR) is the technology specifically designed to scan and convert printed or handwritten text into machine-readable digital data.

A bit-map terminal maps every pixel on the screen directly to a bit in memory. This allows for individual control of each pixel, which is essential for graphical displays.

POS terminals are designed for retail environments to read product data. This includes bar codes and other printed information on tags or labels.

A buffer is a region of memory used to temporarily hold data while it is being moved between two devices or between a device and an application, especially during I/O operations.

In computing, a 'dump' refers to the process of copying the contents of memory or storage to another location, often for diagnostic or backup purposes.

Bar codes represent data by varying the widths and spacing of parallel lines (bars). These patterns are read by optical scanners.

A plotter is a computer printer for printing vector graphics. Unlike dot matrix or daisy wheel printers that print individual characters, plotters draw continuous lines using pens.

Point of Sale (POS) systems are most ubiquitously used in the grocery industry for rapid checkout and inventory management via bar code scanning.

Laser printers operate by using a laser beam to draw an image onto a drum, which then attracts toner to be transferred onto paper, a process based on electrophotography.

Optical Mark Recognition (OMR) is the standard technology used to grade multiple-choice tests by detecting the presence of marks on a pre-printed form.

A joystick is an input device that allows a user to provide x-y coordinate input, commonly used in gaming and CAD applications for precise movement.

Peripherals are external devices that are connected to the CPU to provide input, output, or storage capabilities, such as keyboards, mice, and printers.