Sherr, S, Durbeck, R.C., Suryn, W, Veillette, M."Input and Output The Electrical Engineering Handbook Ed. Richard C. Dorf Boca Raton CRC Press llc. 2000
Sherr, S., Durbeck, R.C., Suryn, W., Veillette, M. “Input and Output” The Electrical Engineering Handbook Ed. Richard C. Dorf Boca Raton: CRC Press LLC, 2000
89 Input and Output Solomon sherr 89.1 Input Devices Keyboards. Light Pen. Data Tablet(Graphics, Digitizer) Mouse· Trackball· Joystick· Touch Input: Scanners Robert C. Durbeck Voice.Summary. Advantages and Disadvantages 89.2 Computer Output Printer Technologies Classification of Printer Technologies. Page Printer Technologies Witold Suryn Serial Nonimpact Printer Technologies. Impact Printer Technologies 89.3 Smart Cards Michel veillette Hardware Architecture.Contact ICC, Contactless ICC .Operating Systems. Standards.Applications. Readers. Card-to-System olutions· Trends 89.1 Input devices Solomon sherr Input devices are those portions of computer, data processing, and information systems that perform the essential function of providing some means for entering commands and data into the system. Therefore, input devices are found in all such systems, but are treated here as a separate equipment group, independent of the total system configuration. However, the place of input devices in evice categories generalized system that accept the inputs. The categories and the devices listed in Table 89.1 are the subject of this section ey Keyboards are essentially electromechanical devices, and are still ubiquitous, in spite of the inroads of other input devices. The primary type of keyboard in use as an input device is the alphanumeric(A/N)form, well known in its typewriter application, but with various additions and expansions consisting of numeric and special function keys. This type of keyboard is shown in Fig. 89.1(b)with a standard QWERTY format, so hamed because of the layout of the top left alpha keys, for the a/N portion, a separate numeric set to the right, and a group of function keys at the top. Other layouts for the a/n portion have been proposed and at least one(Dvorak) accepted by the American National Standards Institute(ANSI), but it has not received much use in spite of its advantages in increased efficiency. At present, the overwhelming majority of system keyboards still use the QWErTY layout, and it is the only one considered here illustrated in Fig. 89.1, a keyboard consists of a number of importance in keyboard design. The relevant characteristics of keyswitch operation are life, actuation force, travel distance, and feedback. Accepted values are shown in Table 89.2 for different keyswitch designs. The elastomer type is preferred to a limited extent over the other two when the electronic audio feedback is included. This indicates that some type of audio feedback is desirable. One form of keyswitch design using an elastomer The material contained in this section is a shortened version of that which appears in Electronic Displays, 2nd ed, by Sol Sherr, Chapter 6, Section 6.1, 1993, published by John Wiley Sons, Inc., and is reprinted here by permission. c 2000 by CRC Press LLC
© 2000 by CRC Press LLC 89 Input and Output 89.1 Input Devices Keyboards • Light Pen • Data Tablet (Graphics, Digitizer) • Mouse • Trackball • Joystick • Touch Input • Scanners • Voice • Summary • Advantages and Disadvantages 89.2 Computer Output Printer Technologies Classification of Printer Technologies • Page Printer Technologies • Serial Nonimpact Printer Technologies • Impact Printer Technologies 89.3 Smart Cards Hardware Architecture • Contact ICC, Contactless ICC • Operating Systems • Standards • Applications • Readers • Card-to-System Solutions • Trends 89.1 Input Devices1 Solomon Sherr Input devices are those portions of computer, data processing, and information systems that perform the essential function of providing some means for entering commands and data into the system. Therefore, input devices are found in all such systems, but are treated here as a separate equipment group, independent of the total system configuration. However, the place of input devices in a representative computer system may be clarified by reference to Fig. 89.1(a), which shows the interface of the main input device categories in relation to the portions of the generalized system that accept the inputs. The categories and the devices listed in Table 89.1 are the subject of this section. Keyboards Keyboards are essentially electromechanical devices, and are still ubiquitous, in spite of the inroads of other input devices. The primary type of keyboard in use as an input device is the alphanumeric (A/N) form, well known in its typewriter application, but with various additions and expansions consisting of numeric and special function keys. This type of keyboard is shown in Fig. 89.1(b) with a standard QWERTY format, so named because of the layout of the top left alpha keys, for the A/N portion, a separate numeric set to the right, and a group of function keys at the top. Other layouts for the A/N portion have been proposed and at least one (Dvorak) accepted by the American National Standards Institute (ANSI), but it has not received much use in spite of its advantages in increased efficiency. At present, the overwhelming majority of system keyboards still use the QWERTY layout, and it is the only one considered here. As illustrated in Fig. 89.1, a keyboard consists of a number of keyswitches whose exact structure is of prime importance in keyboard design. The relevant characteristics of keyswitch operation are life, actuation force, travel distance, and feedback. Accepted values are shown in Table 89.2 for different keyswitch designs. The elastomer type is preferred to a limited extent over the other two when the electronic audio feedback is included. This indicates that some type of audio feedback is desirable. One form of keyswitch design using an elastomer 1 The material contained in this section is a shortened version of that which appears in Electronic Displays, 2nd ed., by Sol Sherr, Chapter 6, Section 6.1, 1993, published by John Wiley & Sons, Inc., and is reprinted here by permission. Solomon Sherr Westland Electronics Robert C. Durbeck IBM Corporation Witold Suryn Gemplus Michel Veillette Gemplus
详 ART OF COMPILING STATISTICS Herman hollerith Patented January 8, 1889 #395,781 n excerpt from Herman Holleriths patent application Having thus described my invention, what I claim as new is(1) The improvement in the art of compiling statistics,which consists in first preparing a series of separate record-cards, each card representing an indi vidual or subject; second, applying to each card at predetermined intervals circuit-controlling index points arranged according to a fixed plan of distribution, to represent each item or characteristic of the individual or subject, and third, applying said separate record-cards successively to circuit-controlling devices acted upon by the index-points to designate each statistical item represented by one or more of said index-points ubstantially as described 3. This patent, along with two others, describes a system for tabulating statistical items represented by les punched in cards. The 1890 U.S. census was completed $5 million under budget and two years head of schedule because of Holleriths system. The punch card system with encoded holes( the code for representing alphanumeric characters with holes was named after Hollerith) was widely used for sorting, counting, and tabulating even into the 1980s Holleriths original Tabulating Machine Company was the forerunner to the computer giant, IBM.( Copyright o 1995, DewRay Products, Inc. Used with permission. e 2000 by CRC Press LLC
© 2000 by CRC Press LLC ART OF COMPILING STATISTICS Herman Hollerith Patented January 8, 1889 #395,781 n excerpt from Herman Hollerith’s patent application: Having thus described my invention, what I claim as new is (1) The improvement in the art of compiling statistics, which consists in first preparing a series of separate record-cards, each card representing an individual or subject; second, applying to each card at predetermined intervals circuit-controlling index points arranged according to a fixed plan of distribution, to represent each item or characteristic of the individual or subject, and third, applying said separate record-cards successively to circuit-controlling devices acted upon by the index-points to designate each statistical item represented by one or more of said index-points, substantially as described. This patent, along with two others, describes a system for tabulating statistical items represented by holes punched in cards. The 1890 U.S. census was completed $5 million under budget and two years ahead of schedule because of Hollerith’s system. The punch card system with encoded holes (the code for representing alphanumeric characters with holes was named after Hollerith) was widely used for sorting, counting, and tabulating even into the 1980s. Hollerith’s original Tabulating Machine Company was the forerunner to the computer giant, IBM. (Copyright © 1995, DewRay Products, Inc. Used with permission.) A
TABLE 89.1 List of Input Devices Category Operation Mode Keyboard Alphanumeric Electromechanical Electromechanical Pen tablet Tablet pointing Coordinates Coordinates Curson Verbal Conversion Data Ep, Eb 网日 圖圖圖圖 FIGURE 89.1 (a)Generalized display-system block diagram. Source: After S Sherr, Electronic Displays, New York: John wiley Sons, 1979. with permission. ) (b) Alphanumeric keyboard. Courtesy of Key tronic. TABLE 89. 2 board Parameter values Parameter Snap Switch Elastomer Foam pad 3.2m 8 mm 10 million cycles 10 million cycles on cycles Feedback Audio mechanical Audio electric e 2000 by CRC Press LLC
© 2000 by CRC Press LLC TABLE 89.1 List of Input Devices Category Designation Operation Mode Keyboard Alphanumeric Electromechanical Keyboard Function Electromechanical Pointing Light pen Screen pointing Pointing Touchscreen Screen pointing Pointing Pen tablet Tablet pointing Coordinates Digitizer X-Y conversion Coordinates Data tablet X-Y location Cursor Mouse Movement Cursor Trackball Movement Cursor Joystick Movement Image Scanner Conversion Verbal Voice Conversion FIGURE 89.1 (a) Generalized display-system block diagram. (Source: After S. Sherr, Electronic Displays, New York: John Wiley & Sons, 1979.With permission.) (b) Alphanumeric keyboard. (Courtesy of Key tronic.) TABLE 89.2 Keyboard Parameter Values Parameter Snap Switch Elastomer Foam Pad Key travel 3.8 mm 3.2 mm 3.8 mm Force >60 gm >50 gm >30 gm Life 10 million cycles 10 million cycles 10 million cycles Feedback Audio mechanical Audio electric Tactile
Backing Board nd sle Pad Card (b) Pivot Plate FIGURE 89.2 (a) Elastomer-type keyswitch. (b)Snap switch. Source: After H. Brunner et al, "Effects of key action design on keyboard preference and throughput performance, "Micro Switch. with permission.) or"molded boot " is shown in Fig. 89. 2(a), in which the boot consists of two collapsible domes. In this desigr the internal movement of the keyswitch is completely silent so that some source of sound must be added to achieve the desired audible feedback. The snap switch design shown in Fig. 89.2(b)has built-in sound and achieves a small reduction in insertion errors over the elastomer design with audio feedback. The life requirement is estimated on the basis of workstation users operating at approximately half the accepted rate of 20 million actuations per key used for electronic typewriters. The actual layout and content of the keyboard may vary greatly, ranging from the standard typewriter arrangement, through different com binations of alphanumerics and symbols, to the special-function keyboards that contain legends and symbols specific to the particular application. However, the outputs of each type are the same in that they must contain coded signals that relate the action to be performed by the information system to that defined by the key being operated, in terms of the input code of the system. Thus, many of the keyboards output the ASCII code, and the system is usually designed so that it can accept this type of standard code. Incidentally, ASCIl, the acronym for American Standard Code for Information Interchange, is the standard means for encoding alphanumerics and a group of selected symbols for transmission to a display system, among others. It is the standard code used in the United States and most other English-speaking countries and corresponds to the ISO seven-bit de. The seven-bit ASCII is usually used, and it should be noted that for serial data transmission an eighth bit is added for parity. Various keyboard arrangements are possible, and many variants are found in particular pplications. The means for coding the key operation may be through magnetic reed relays, solid-state circuits, or more exotic devices such as Hall effect sensors. These device characteristics are only incidental to the operation and beyond the scope of this chapter. Similarly, we do not discuss the human-factors aspects of keyboard design, not because they are not important, but because, apart from the visual considerations, the other factors have to do with tactile and physical features best left to others Light Pen The light pen initially was a very popular means for accomplishing manual input to the random deflection nformation display systems, but fell out of favor when raster systems became more popular due to its being e 2000 by CRC Press LLC
© 2000 by CRC Press LLC or “molded boot” is shown in Fig. 89.2(a), in which the boot consists of two collapsible domes. In this design, the internal movement of the keyswitch is completely silent so that some source of sound must be added to achieve the desired audible feedback. The snap switch design shown in Fig. 89.2(b) has built-in sound and achieves a small reduction in insertion errors over the elastomer design with audio feedback. The life requirement is estimated on the basis of workstation users operating at approximately half the accepted rate of 20 million actuations per key used for electronic typewriters. The actual layout and content of the keyboard may vary greatly, ranging from the standard typewriter arrangement, through different combinations of alphanumerics and symbols, to the special-function keyboards that contain legends and symbols specific to the particular application. However, the outputs of each type are the same in that they must contain coded signals that relate the action to be performed by the information system to that defined by the key being operated, in terms of the input code of the system. Thus, many of the keyboards output the ASCII code, and the system is usually designed so that it can accept this type of standard code. Incidentally, ASCII, the acronym for American Standard Code for Information Interchange, is the standard means for encoding alphanumerics and a group of selected symbols for transmission to a display system, among others. It is the standard code used in the United States and most other English-speaking countries and corresponds to the ISO seven-bit code. The seven-bit ASCII is usually used, and it should be noted that for serial data transmission an eighth bit is added for parity. Various keyboard arrangements are possible, and many variants are found in particular applications. The means for coding the key operation may be through magnetic reed relays, solid-state circuits, or more exotic devices such as Hall effect sensors. These device characteristics are only incidental to the operation and beyond the scope of this chapter. Similarly, we do not discuss the human-factors aspects of keyboard design, not because they are not important, but because, apart from the visual considerations, the other factors have to do with tactile and physical features best left to others. Light Pen The light pen initially was a very popular means for accomplishing manual input to the random deflection information display systems, but fell out of favor when raster systems became more popular due to its being FIGURE 89.2 (a) Elastomer-type keyswitch. (b) Snap switch. (Source: After H. Brunner et al., “Effects of key action design on keyboard preference and throughput performance,” Micro Switch. With permission.)