CA1325481C - Handwritten keyboardless entry computer system - Google Patents

Abstract

Abstract Of The Disclosure A keyboardless entry computer system includes a transparent input screen that generates positional information when contacted by a stylus, and a display screen mounted physically below the input screen such that a character that is displayed can be seen below the input screen. The system includes a computer that has been programmed to compile the positional information into Strokes, to calculate Stroke characteristics, and then compare the Stroke characteristics with those stored in a database in order to recognize the symbol drawn by the stylus. Key features of the system are:
(1) transparent position sensing subsystem; (2) underlying display on which to mimic drawing of sensed positions and to show characters or symbols; (3) means to convert sensed positions first into plotted Points and then into recognized characters or symbols; and (4) means to "learn" to associate sensed input positions with a character or symbol.

Description

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1323~81 The present invention relates generally to a Xeyboard-less input syst~m to a computer, and when combined with a central processing unit, to a keyboardl~ss entry computer system. More particularly, the present invention relates to an information storage, manipulation and transfer device on whic:h text, data, computer commands and functions are entered by writing alphanumeric or any other characters and symbols by hand with a penlik~ stylus on an Input/Output tI/O~ screen.
Larg@ amounts of information and sophisticated applica-tions software are now available on co~ventional keyboard com-puters. The utility of this information and of application software could be greatly increased if text and dat~ could be :
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entered and applications software manipulated by writing in a normal fashion directly on a flat display. Thus, there is a need to allow the utility of computer technology to be extended for use by non-keyboard oriented individuals. There is also a need for a portable computer system that is lightweight, reli-able, accurate, inexpensive and permits use while standing or walking. One way to reduce expense and size and increase utility is to employ a keyboardless ~ntry system, such as a touch screen. However, this type of input device does not easily allow accurate detailed input within a real time framework with high resolution in a manner which is famiiiar and natural to the user.
Many positioning technologies can be used to meet the requirements of the position sensing input technology.
Essentially these requirements include accuracy, resolution and speed. The technologies include: mechanical, electrostatic, electromagnetic, acoustic, optical, and inertial. The desire in this system is to have its use as similar as possible to writing with pen or pencil on paper. One problem is proximity ~--- a pen on paper only leaves a trail when actually in contact.
Many of these technologies require an additional "pen down"
sensor which is awkward to use in many comme~cial pens, Another problem is writing angle -- a pen leaves the same trail independent of writing angle. Many of these technologies have the position detector displaced from the pen tip, so pen angle causes erroneous displacements. Beyond these general problems, each technology has numerous advantages and disadvantages in (1) the pen: size, weight, shape and whether it needs to be powered and/or wired, and (2) the writing surface:
transparency, smoothness, "feel", and whether or not physical contact is needed (as opposed to pressure transmitted through overlaying sheets of paper).

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A number of self-contained devices for viewing and processing large amounts of information are known. Most employ optical, magnetic or solid-state electronic storage means to store data. Illustrative of this body of art is U.S. Patent 4,1~9,417 to Rubincam which discloses a port:able electronic book configured to provide selective page by page call-up of large amounts of digital data and disp~ays it on a flat, solid-state screen. The preferred embodiment in the Rubincam patent uses an insertable holographic card, which may contain several hundred pages of text in digital form, as the main storage means. Rubincam's device, however, does not allow new information or text to be entered or manipulated.
In U.S. Patent 4,016,542 to Azure an electronic data collection system is disclosed which employs a solid state Ran-dom Access Memory (RAM) for its primary memory. This patent, which discloses a conventional keyboard for data entry, is di-rected to a hand-held portable data storage and transmission system, as well as an LED display and various Input/Output (I/O) connectors.
U.S. Patent 3,487,731 to Frank discloses a means of converting handwriting into character data through the use of a computer system. The disclosed invention is based on matrix pattern matching and does not employ any coincident display technology.
U.S. Patent No. 4,491,960 to Brown shows a handwritten symbol recognition system in which an array of image Points, in the form of a raster line sampling, is converted into segment-oriented lists which are filtered and compressed to obtain topologic features which are then analyzed with a logic tree decision mechanism.

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~32~3~81 U.S. Patent No. 4,262,281 to Buckle et al. discloses a handwriting recognition deviceO The disclosed embodiment is for use with a host computer and does not employ coincident display technology.
U.S. Patent No. 4,475,239 to Van Raamsdonk discloses a text editing apparatus. The '239 patent calls for the use of paper as a medium for the entering of editing functions and requires a conventional keyboard for the inputting of text.
U.S. Patent 4,521,909 to Wang shows a dual level pattern recognition system. The system is designed for use with an optical instrument.
U.S. Patent 4,520,357 to Castleberry et al. discloses an electroscopic information display and entry system with writing stylus. The disclosed embodiment does not claim to have the speed or accuracy to enable handwritten character recognition.
Additional prior art which discloses portable elec-tronic devices that provide large amounts of various ~ypes of stored information include U.S. Patents 4,218,760 to Levy;
4,4115,486 to Laine; and 3,932,859 to Kriakides et alO The ~ ~-Levy and Kriakides et al. paten-ts pertain to electronic dic-tionaries, while the Laine patent discloses a programmable television reminder system. None of these devices disclose the use o a handwritten input.
In U.S. Patents 4,071,691, 4,129,747, 4,198,539, 4,293,734, 4,302,011, 4,353,552, 4,371,746 and 4,430,917 to William Pepper, Jr. v,arious methods or machine-human interfaces using finger touch are disclosed. The preferred em~odiments in each of these inventions lack sufficient speed and resolution to allow handwritten character recognition with a stylus cmd are designed for other puxposes. U.S. Patent 4,318,096 to Pepper 1 3 2 ~ ~ 8 1 ~:
teaches the use of a conductive stylus. The '096 patent pertains to graphlc design and allows llne width and line intensity to vary by applying pressure on the stylus with the results displayed on a con~entional C~T screen. U.S. Patent 3,699,439 to Turner and U.S. Paten~ 4,055,726 to Turner et alO discloses two msthods for electronic po~tion sensing through the use of a pro~e.
It is an obJect of the present lnvention to prov$de a novel apparatus and method for recognlzing handwr~tten character~.
According to one aspect of the present invention there is provided an apparatus for recognizing handwritten symbols, comprising:
a display screen;
hand-held means, coupled to said display screen ~or writing a handwritten symbol over at least a portion of a first area of said display screen;
means, coupled to said display screen, for digitizing said handwritten symbol to provide a digitized symbol;
means, coupled to said display screen and said m~ans for digitizing, for displaying an image of the handwritten symbol on said display screen in at least a portion of said first area as it is written;
means, coupled to said display screen, for executing a plurality of different editing functions;
means, coupled to said means ~or digitizing, for correlating said digitized symbol with at least one of a plurality of predetermined symbols including a plurality o:E
font symbols and a plurality of editing symbols, by csmparing characteristics of said digitized symbol with stored :~
characteristics of at least some of said plurality of predetermined symbols, to provide one of said plurality of predetermined symbols as a designated symbol which is correlated with said handwritten symbol;
means, coupled to said display screen for displaying a computer-generated symbol on said display screen wh~n said designated symbol is a font symbol and for executing at least a first of said plurality of editing functions when sai~
designated symbol is a ~irst of said plurality of editing symbols, and ~or executing at least a second of said editing _ 5 _ ,,r.. ~1 functions different from said first editing ~unction, when said designated symbol is a second of said plurality of editing symbols.
According to another aspect of the present invention there is provided a method for recoynizing handwritten symbols, comprising:
providing a display screen;
writing a handwritten symbol over at least a portion of a first area of said display screen;
digitizing said handwritten said handwritten character to provide a digitized symbol;
displaying an image of the handwritten symbol on said display screen in at least a portion of said first area as i~
is written;
correlatiny said digitized symbol with at least one v~ a plurality of predetermined symbols including a plurality of font symbols and a plurality of editing symbols, by comparing characteristics of said digitiz~d symbol with stored characteristics of at least some of said plurality of predetermined symbols, to provide one of said plurality of predetermined symbols as a designated symbol which is correlated with said handwritten symbol î
I displaying a computer-generated symhol on ~aid ¦ display screen when said designated symbol is a font symbol;
¦ executing at least a firs~ of ~;aid plurality of I editing ~unctions when ~aid designa~ed s~bol i5 a first o~ :
! said plurality of editing symbols; and executing at least a second of said plurality of editing functions when said designated s~bol is a second of said plurality of editing symbols.
Pref~rably, the present keyboardlQs~ computer sys~em has the abllity to recognize ~nd di~pl~y Handwrltten S~nbols and I cau~e the oomput~r to display Font !3ymbo:L~ and, 1~ d~ired, ts I execut0 editing unctlon~ pur~uant to Ed:Ltlng S~mbol~, qulckly, ily and at rs~30n~ble co~t.
~ Prefer~bly, a co~puter hou~ing i8 provlded with a ~lat ;, display pa~el on whlch a u~er ~ay "wrlt~" wi~h a stylu~, 3 capablllty to r~cogniz~ ~andwrlt~n SYm~D1~ writt~n on *Ae panel with the Stylu~ and co~v~rt ~h~ to di~ y~d Font Sy~bol~ ~nd/or - a -~ , :
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to execute Edltlng Function~ wlth Edlting Symbol~, 811 wlth a mlnlmum of ~chnlcal complexlty for th~ us~r.
It 19 ~180 pref~rred that once the k~ybo rdless, portable computer ls losded with th~ d~slred lnfonmatlon and appllcation~ ssftware, informatlon and softwar~ can be used and r~sponded to wlthout regulrlng skllls or knowladge related to stats-of-the-art eomputer~ or o~h~r da~a sourc2.
Th~ sa~e-o~-us0 o~ the ~nput tec~oloyy of th~ pr~s~nt lnv~ntlon enh~nces thQ utlllty of th~ compu1:er for keybo~rd orlentad lndlvldu~ls. Ths port~bil~ty of th0 ~resent d~vice also allows it to b~ U8Hd in ~ppllc~tlon~ cnd ~ettin~ ln which portable keyboard computers ~re ~w~ward, dll:ficult or lmpo sible to U8e . For ex~mpl~, ~ ~ult~plicity o - 5~ -' 325~8~

blank, fully or partly completed forms may be stored in the . : .
portable computer memory. In a hospital, "sheets" of patient data can be stored in the memory of the portable computer, called up by a nurse as the nurse makes rounds and relevant data, such as blood pressure, temperature, etc., can then be entered manually with a stylus. These corrected or expanded forms can then be down-loaded into a central computer memory.
The requirements of the position sensing input tech-nology are accuracy (Point to Point), resolution (absolute position) and speed (Points per unit time~ to adequately define the written Stroke for recognition analysis. For the recognition apparatus and methods presently used, as described below, the present minimum requirements are: accuracy of .005 inch, resolution of .015 inch, and speed of 150 Points per second. This accuracy allows a 1/4" high writing line with over 10 raw input Points along a Stroke of a small letter. The resolution provides positioning of the symbol to within two pixel~ on a present display of 640 pixels to 9 inches. The speed permits about 50 raw input Points for a rapidly written single letter (1/3 second).
One emb~diment of the present invention comprises a transparent input screen. As the use,r writes alphanumeric or other characters or symbols on the input screen, the character is represented as a stream of Points Pmulating written input with pen on paper. Once the discrete alphanumeric and other characters or 5ymbols are complete, they are translated into com-puter text or computer commands that can be displayed on a dis-play screen at a location that is preferably beneath the area on the input screen where they were entered. The embodiment also comprises a pattern recognition algorithm which allows the translation of any written character or symbol, such as ideographs and scientific ~ymbols, into computer text.

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~ In a particular, presently preferred embodiment, a keyboardless computer according to the present invention is con-~ figured as a manipulation and display device comprising a trans-I parent touch screen and associated electronics placed over an 80 column by 25 line or larger display screen; a stylus for 1 entry of data; a microprocessor and storage meansj artificial f intelligence/pattern recognition software and editing software;
and a battery power system; and other I/O means.
~, As used herein, "Handwritten Symbols" are any symbols capable of being handwritten and having communicative effect.
By way of example, and not limitation, numbers, letters, j "Kanji" (Japanese ideograms) or other language symbols, editing symbols and engineering, scientific, architectural and ~ mathematical symbols are Handwritten Symbols. Other examples ¦ of Handwritten Symbols are free-hand drawings or signatures or any other such written information uniquely configured by a ~ particular writer. Handwritten Symbols may also include 3 Editing Symbols (defined below).
As used herein, "Font Symbols" are computer-generated symbols which are displayed in a predetermined font format. By way of example and not limitation, alphanumeric symbols may be Font Symbols and displayed in numerous font formats. Japanese or Chinese "ideograms" may also be Eont Symbols, as may be engineering, scientific, mathematical; architectural or other such characters. Other examples of Font Symbols include any form which can be stored and displayed by a computer, e.g., a ~3 drawing of a car or a house.
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.1 As used herein, an "Editing Symbol" is ~ symbol (such ~¦ as a caret, horizontal line, short vertic~l line~ long vertical line, etc.) which is intend~d, when recognized, to cause the computer to execute a particular Editing Function ~defined ; below), ~uch as insert test ~caret), delete text (horizontal , . , 1 3 2 ~
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line), delete a letter (short vertical line) or move a margin (long vertical line), to list a few representative examples.
"Editing Function" means any computer-generated text editing operation, such as by way of example and not limita-tion, insert text, delete text, move text and substitute text.
Some primary Editing Functions are listed on paged 40 and 4}
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Thus, the present inven-tion provic~es improved methods and apparatus for providing a keyboardless computer on which usua} computer functions are per-formed by writing in a norm~l manner with a pen-like stylus on an input screen placed directly over a flat display.
The keyboardless computer provided is ideally config-ured for use by non-keyboard oriented individuals, by keyboard individuals for whom the utility of the computer is enhanced, and in various settings and applications in which keyboard entry is awkward or impossible.
Preferably, means are provided whereby computer-based information and applications soft-ware can be loaded into a portable device for later viewing, manipulation of text and data, and adding new text and data in a normal handwriting mode. Thereafter the user may transmit this comp~lter text to another computer, a simllar clqvice, an external electronic storaye device, a hard copy printer, or through a telecommunications system. It ls als~ ore~.rr~ ~h~t ~ the present inven~ion prc~vldes acomputer capable of recognizing 9 Handwritten Symbols with a high degree of accuracy and of ~ "learning" individual styles of handwriting.
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132a481 Preferably, the present invention also provides a portable keyboardless computer in which data and commands are input with the use of a . stylus.

Embodiments of the present invention will now be described by way of example only with ~-~ reference to the accompanying drawings in which '~, Fig. ~ is a schematic block diagram of a portable handwritten, keyboardless entry computer system;
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Fig. 2 is a perspective view of the ~,~ housing containing the operating elements of the system shown in Figure l;
, Fig. 2A is an enlarged portion of Fig~ 2, -~ with parts removed to show the positional relationship between the touch input screen and tha display screen.
~s .. r Fig. 3 is a schematic diagrammatic view of ~ the input screen, stylus and associated electronics;
:~q Fig. 4 is an overall schematic system block diagram of the apparatus of a keyboardless enkry computer system;

~ Fig. 5 is a schematic block diagram ;~ depicting the movement of data within the system when modified by handwritten chaxacters and commands;

Fig. 6 is an overall sy~tem block diagram ~ depicting the hierarchy of software used to operate ,I the sytem; -~

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Fig. 7 is a generalized block diagram of the character and pattern recognition alogoithm.
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~, Figs. 8A and 8B together are a detailed block diagram of the patter recognition alogroithm.

Fig. 9 is a schematic block diagram of the StroXe characterization subroutine.

Fig. 10 is a top plan view of a screen illustrating the "initializing" of the database for Handwritten Symbols.

Figs. llA through llI are a series of top ~' plan views of screens depicting the operation of a text editing system.

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,, Figs. 12A through 12G are a series of top plan views of scraens depicting the operation of a data entry system.
Fig. 13 is a generalized block diagram of the Linus Editor.

With refereDce no~ to the figure5, where1n 11he numer-als indicate like elements throughout the several views, and in particular wlth reference to Fig. 1, an overall block diagram of ~; a portable handwritten, keyboardless entry computer system 10 is ~ depicted. The complete computer system is encased in a housing ¦ ~ 12, indicated graphically by the dashed line, and includes a con-ventional, general purpose digital microcomputer 14, described in greater detail hereinbelow. Input information is provided to microcomputer 14 by stylus 16 "writing" on writing or input screen 18. Stylus 16 (Fig. 2) is connected to the computer of system 10 with wire 17 (Fig. 2). As stylus 16 "writes" on input screen 18, a plurality of locating signals representative of a plurality of corresponding positional coordinates are transmitted to microcompu~er 14. Microcomputer 14 has been programmed in accordance with a computer program de.scribed hereinbelow, to recognize the stream of locating signals and to store these signals in a computer memory. The programmed microcomputer 14 also provides a corresponding plurality of display signals to a display screen 20. ~oth input screen 18 and display screen 20 are c]escribed in ~reater detail hereinbelow.
Referring now to Fig. 2, there is shown a perspective view of ~eyboardless computer system 10.
~I Keyboardless computer system 10 is con-tained in housing 12, which is a rectangular enclosed casing having a sloped top surfac~ 22 with a multi-line, solid state ,~ , ~.
~;' 1 32~481 display area 24. Input screen 18 is depicted in Fi~. 2A as be-ing positioned over display screen 20. In this example, display screen 20 displays a plurality of horizontal lines 25 with the following indicia:

- Name Address Handwritten entries are made above each line 25. The distance or space between two lines 25, denoted 26, is used by the system to normalize all distances, and lin s 25 themselves serve as a reference axis or base line.
Below display area 24 on top surface 22 is a key input section 26 comprised of a plurality of "Softkeys" 28.
Softkeys 28 can be programmed by the operator for any purpose, such as to enter computer commands. Exemplary commands for Softkeys 28 are "store,ll l'recall," and '7delete. Il In addition, ~ Softkeys 28 can be used to switch loetween different programs or i, between modes ~e.g. data entry mode and edit mode). However, Softkeys 28 are optional and are used to supplement the input obtained by handwriting the entries. Stylus 16, used for writing input data and commands in display area 24, also is used to activate the selected Softkey 28. An ON-OFF switch 30 is positioned on the side of housing 12 adjacent to Softkeys 28. A data output or peripheral connector 31 is located on the , upper right side of housing 12.
~ Input screen 18 can be a conventional resistive type ; touch screen in which a voltage is applied ko the screen edges and a stylus detects the voltage at the touched location. The writing surface is a transparent material, typically glass, coated with a thin, uniform, conductive layer (presently, vacuum deposited indium tin oxide). Vertical bus bars or conducting strips (not shown) are used along the two sides to :

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~'i,` apply the reference voltage to deter}nine the "X" coordinates of the stylus position and 7!i horizontal bus bars or conducting strips (not shown) are used along the bottom and top to apply the reference volt~ge to deterrnine the "Y" coordinates of the stylus position. In this embodirnent, stylus 16 is merely an electric probe that, when physically in contact with the conductive layer, detects the local voltage at the Point of contact, which w;ll vary with the distance from the conducting strips or bus bars. With the orig;n at the -~
Point of voltage application, the X,Y coordinates are inversely propor~ional to ~he impressed voltage. Stylus 16 must make good contact to minimize adding resistance that would lower the voltage detected, and thus add an erroneous distance increment. In a presently preferred embodiment, a soft graphite tip is used. The voltage is conducted from the pen through a wire, such as wire 17 in Fig. 2, to an analog to digital converter for use in the computations desc~ed below. The stylus may be a charged "pen" as described herein, a light pen as is well known in the art, or any other hand-held device which can outline Handwritten Symbols on a screen.
An example of a conventional electros~atic screen is di.~clos~d in the aforementioned 4,318,096 Pepper patent. This resistive type scr en has th~ advantage J that the inference caused by the user's hand touching the screen is minimiz~d.
Both horizontal and vertical position sensing is provided by alternately switching the voltage impressed on a conductive layer between the pairs of horizontal and vertical bus bars by an interface and multiplexer controlled by a microcomputer or microcontroller. In one commercially available input or touch screen, the bus bars are broken into a series of short strips with diodes to prevent the horizontal strips ~rom shorting out vertica~ strips and vice versa. This technique is used in a commercially :' ;.' , .

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l3~81 available touch screen f~om Touch Technologies of Annapolis, MD. and Elographics of Oak Ridge, Tenn.
Referring now to Fig. 3, an altemate embodiment of a low power position sensing novel input screen 33 is described in greater detail. Input screen 33 is also for deterrnining an X,Y position on an electrically resistive plate 34. A stylus 35 containing a voltage source, such as battery 36 or a vol~age transmitted to stylus 35 from an external source such as ~he system power supply, is used to touch screen 34 and apply a vol~age at the touched position. When the touched position is charged by stylus 35 with a positive voltage with respect to a plurality of plate measurement Points 37, the voltages at these Points will vary wi~ the distance to the pen position, such as position X" Y" indicated at 38. These voltages are sequentially measured in the X and Y direetions by using conventional means, such as disclosed in the aforementioned prior arts patents. In ~ig. 3 these means are a conventional interface/multiplexer 42. A conventional Analo,g-to-Digital conveIts 43 converts the detected voltages into a digital signal. A microcontroller 44 receives the digital signal, performg standard checks to ensure the signa~'s numerical valu~ is "valid;' (e.g. is within the possible range of voltages), and then converts the voltages to X and Y distances in the manner described herein. Micr~ontroller 44 is conventional, but could be replaced by a system computer. Microcontroller 44 pro~rides a digital signal representative of the X and Y distances to measuring Point 3~ ~o an output pore 46. Port 46 casl be a ccnventional PcS 232 port. Alternatively, micr~controller 44 ould ~nslate Point Xl, Yl to any othes reference Point, such as a Point on base line 25 (Fig. 2~.

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As long as there is no contact by stylus 35 at posi-tion 38 or any other position on plate 34, no current flsws and :,::
power consumption is minimal. An incident measurement of the 7 voltage at the measurement Points may occur by using ramped 3~ voltage at the positioning Point and timing when the measuring Ij Point voltage exceeds a preset back voltage.
17 The scope of this invention covers the followinq ~
options for the input or touch screens 18 and 33: resistive ~-~ plate 34 or its equivalent for screen 18 can be transparent or J translucent and the position Point oan be made by a stylus or a ~; finger of the user, or a connecting Point of an overlapping conductive screen (such as the commercially available touch screens from Touch Techno]ogy, Annapolis, MD.). Input screens 18 and 33 can be a physical solid surfaee which is transparent 7, or translucent and can be glac~s or plastic such as Mylar. Th77 surface can be coated with a conductive/resistive substance , like indium tin oxide. Other physical surfaces can use sound j or electromagnetic radiation transmission from the touched ~ position to a reference Point or Points and the distance i5 determined by the time delay or phase shift. Alternatively, input screens 18 and 33 can use an ethereal or geometric surface defined by an electromagnetic, optical or sonic field.
Position detection can be accomplished with electrical contact closure by resi.stive, capacitive or inductive çoupling, remote sensing by sonic, electric or magnetic ~ields or by light (W, IR, or microwave) scanning.
The advantages of the low power position sensing input invention over other such screens are: l) $he invention makes stand-by power requirements minimal; 2) thé invention eliminates distortion due to opposing parallel "bus" bars in conventional touch screens; and 3) when a ramped voltage is employed, the ~, -14-132~81 . ;~ . . `~ ~
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inven~ion eliminates the need for an A/D chip which is a major cost factor in state-of-the-ar~ touch screen technology.
The coeff-cient of friction of the screen 18 is desir-ably selected to be "rough" enough to offer some resistance to the movement of stylus 16 on the screen. If ~he screen were too smooth, the stylus would slide too easily and would be difficu}t to control.
Reference is now made to Fiy. 4 which discloses an ; overall system block diagram of the major electronic circuitry used in the preferred embodiment of the present invention.

Microcomputer 14 includes a microprocessor 50, interconnected A, ~ to a plurality of other electronic elements by means of data path or bus 52. A Read-Only-Memory ~ROM) 54 which is ~3 programmed with the operating and application programs and a '' battery powered Random Access Memory (RAM) 56 i5 connected for bidirectional data flow onto bus 52. Microprocessor 50 may be j a conventional single-chip eight-bit or sixteen-bit device :l which functions to execute the fixed control programs residing in ROM 5a, and further receives control programs from and provides control signals to the other electronic elements via 3 bus 52. Microprocessor 50 may be of the type commercially j designated Z80*(manufactured.by Zilog Microcomputers of Cupertino, California), of a type 8088*device (manufactured by Intel Corp. of Santa Clara, Caliornia) or any similar or more ~, powerful microprocessor. ROM 54 may be of the type 2564*or 4764*, both manufactured by Texas Instruments of Dallas, Texas.
The storage capacity of RAM 56 is determined in part by the ~ sizes of the application programs, the operating program and !`1 the database. As discussed below, RAM 56 may be of the static SRAM or dynamic DRAM type. The prim~ary requirements of RAM 56 ~, are that it have sufficient storage capacity and that it require a minimum of input power.

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A battery 58, such as a lithium battery, provides -power for making the memory of RAM 56 non-volatile for extended ~-periods of time. A battery pack 60 containing the well-known rechargeable types of batteries is used to provide the various voltage levels rec~uired by the other electronic elements of microcomputer 14.
Alternately, the storage function o RAM 56 may be served by a non-volatile device which requires no power for main-taining storage, such as an electronically erasable snd repro-grammable memory (~E~ROM), or devices using magnetic bubbles or capacitance. State-of-the-art disk or Sape may also be used for mass storage. Suitable bubble memory devices include types 711C*and 7114*which have storage capacities of l megabit and 4 megabits respectively. (Both are manufactured by InteL Corp.).
Furthermore, it is possible to use a single integrated circuit chip which includes microprocessor 50, at least part of ROM 54 and at least part of R~M 56.
Also connected to bus 52 is an EIA RS-232 serial inter-face 62 which provides a means for inputting and outputting data.
Data is provided to bus 52, (usually to RAM 56) by interconnect-ing an external data source to RS-232 port 52 directly to the microprocessor 50 and other elements of the microcomputer 14.
Offloading data from RAM 56 can also be done by microprocessor 50 to an external computer, o~her data gatherlng device, a mas3 data storage device (e.g. floppy and hard dlsk drlveq) or an electronic telecommunications system. In lik~ manner data can be communicated through port 62 to a prlnter (not shown) from interconnecting bus 52.
Stylus 16 is used to write on input screen la and to cause the generation of X,Y coordinate information by conven-tional touch screen interface electronics circuitry. The coor-dinate information is communicated via the bus 52 for control * Trademark .
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use by system 10. The solid state display 20 consisting of a ~ multi-line display -- illustratively 80 columns by 25 lines --f~ is interconnected to bus 52 through a display interface 66.
The fundamental requirements for the display are that it be sub-stantially flat and sufficiently thin for use in the present invention. The display may be of the following types: scanning types such as a cathode ray tube, projected types such as a rear-view projector, light emitting array of Points types (e.g., electroluminescent or plasma discharge~ and light blocking array of Points types (e.g., liquid crystal displays, solid state PLTZ or magneto-optical). In addition, it is preferable that the display be compatible with input screen 18 in size, configuration and transparency, and that both be low power consuming types.
The X,Y coordinates for this invention are input to keyboardless computer 14 via input screen interface electronics 64 and communicated via bus 52 to microprocessor 53 which executes programs stored in ROM 54 and RAM 56.
The number of Points (i.e., sets of X,Y coordinates) used in defining each Handwritten Symbol and the speed at which Points are identified are important to the practical utility of the invention. It is desirable to use at least about 100 Points per inch and at least about 100 Points per second to define Handwritten Symbols. It is to be noted that the more ~ Points per inch that are identified, the greater the accuracy ¦ of the system in identifying Handwritten Symbols -- however, ~J more Points being identified will slow down the speed of Y identification and require more computer memory. Accordingly, a balance will have to be achieved, based on the size (avail-~ able memory and processing ability~ of the computer system and j the re~uirement for speed of response and accuracy. For most , ~ -17-:`: : ' 1 3 2 5 ~
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purposes, standards in the range from about 100 Points per inch and per second to about 200 Points per inch and per second will be suitable. -~
It is also to be noted that the greater the precision of the system in identifying the X,Y coordinates of each Point the fewer the number of Points needed to be identified per inch and per second to accurately identify Handwritten Symbols. Con-versely the less the accuracy, the more Points that are needed.
Point resolution is needed to place Points where intended, e.g., to write an editing symbol precisely between the two characters. Ideally, resolution to a single display pixel is desirable. However, operationally, resolution within two displayed pixels is sufficient for a display with 640 pixels in a nine inch horizontal scanline.
When switch 30 ~Fig. 2) is positioned to "power on", the basic display mode is activat~d and microcomputer 14 (Fig. 4) programmed by the operating system, causes a menu to be displayed on display screen 20 (Fig. 1~. The menu presents various software options. A primary software function, editing, functions in a manner similar to conventional word processing software with the difference being that handwritten characters, symbols and commands are;interpreted by the system as if they were entered from a conventional keyboard. The system is capable of learning the editing symbols used by a particular writer for functions such as indent, insert, delets, move and reformat and translates those symbols into digital command functions. Optionally, Softkeys 28 (Fig. 2), activated by touching those areas on the input scree~ with stylus 16, ~unction like conventional hard function keys on a computer keyboard.

The present invention is particularly adapted for use as an interactive screen editor or word processor. After a ~:
32548~
writer retrieves a document by (for examp~e) touching the displayed name of an existing file with the stylus or by writing the name of the file on the screen, all usual editing functions can be performed with stylus entry. When the user wishes to change a displayed character or symbol, he may simply write over the displayed character or symbol and as described hereinbelow the pattern recognition algorithm will translate the written entry into computer text. For example, the editing software allows text to be eliminated by simply drawing a line through it and a conventional caret symbol may be used to change the operating mode to the insert mode. In the insert mode, display screen 20 provides additional space for entry of handwritten characters or symbols which are inserted in the text after the Point where a caret was written in. Text can be moved simply by placing brackets or other user-defined delimiters around a displayed phrase or word and writing a caret or other user-defined symbol in the area of the text in which the user wishes this material to appear. New margins can be set by drawing vertical lines down the side of the displayed text where the new margins should appear.
The basic editor software also allows new documents to be created by simply writing Handwritten Symbols on the screen.
All documents can be stored, changed and communicated in the manner in which these functions are accomplished on a conventional word processing system with the difference that these functions are accomplished with handwritten Editing Symbols on the (optional~ screen or by touching the Softkeys with the stylus. The composite text thus produced and stored can be subsequently offloaded through the RS 232 port 62 (Fig.
4) to another computer, a similar device, an external data gathering device or recording device, into a printer or through a telecommunications system.

!

`: : 1 3 2 ~ 4 8 1 In addition to these major operating modes, a number of ancillary elements and features add to the utility of the present invention. A conventional ~phanumeAc keyboard (not shown) containing a full set of keys can be connected to a cvnventional keyboard interface ~not shown) to support the ent~y of alphanumeric ch~acters. An AC/I)C power connector may also be uscd in those applications when portability is not needed and when needed to meet the power requirements of screen technologies such as gas plasrna displays and electroluminescent displays.
In actual use the keyboardless computer can function in ~ny application or environment in which handwritten input translated into computer ~xt is useful or necessary. Illustratively, the devic~ un function as a new gene~ation word processor, or for use in fields such as sales, nursing, inventory control, census taking, claims adjusting, to narne just a few of the many uses of the invention, or as a general learning and testing device in education. Since the pattern recognition softu are can learn and translate into computer text from l~nguages which are not made up of a small or limited set of alphanumeric characters (e.g., Japanese, Korean, and Chinese), it has particular utility for word pro essing and ~elecommunications in these languages.
In the practice of this invention, it is particularly desirable to use a single computer screen to display any initial fonns, Font Symbols or other displays ~o be edited, and to create a nearby "window" of blank space where Handwritten Symbols are to be written, displayed and identified, and where the Font Symbols corresponding to the Handwritten Symbols are to be displayed. In this way, the user c~n view ~he text being edited and the propvsed insert or ~hange without significant moYement ~if any) ~ the head and eyes. Ihis is illust~ated in ~igs. llA to llD. This fea~ure of the invention (proximity on on~ screen of text to be edited and the windvw into which new text is to be handwritten) is very important to the simple, rapid, comfortable use of the invention.

132~4~1 In a preferred embodiment of this invention, the system "learns" the handwriting of a particular user prior to actual use For cxarnple, if using the Roman alphabet, the twenty-six letters of the alphabe~ the numerals from 0 to 9 would be inserted into the database. Punctuation symbals, such as periods, commas, question marks, colons, semi colons, hyphens and the like could also be inserted. There ;s virb~ally no limit to the Handw~itten Symbols which can be recogni~ed and stored in the database. Of course, the computer will have to store a suitable array of ~ont Symbols for conversion of the Handwritten Symbols. Different sets of ~ont Symbals could be created and stored in the pennanent memory sf the computer, as in ROM c~ip 54. For example, in English language usage, a chip could con~ain one (or more~ fonts of numbers and letters, suitable punctuation symbols and appropriate mathematical symbols. Other chips could h~ve stored Font Symbols ~or the Arabic, Cyrillic or Greek alphabets, Japanese, Chinese or Korean "Konjin, symbols for use by architects or engineers, or chemical symbols (~, benzene rings and the like).
In Fig. 10, one of a series of learning screens is displayed and the user is prompted to write the numbers û through 4. ~he computer will at~empt to match the written numbers with the exis~in~ database (if any). If it cannot be ma~ched because there is no existing database or because there is a poor match with an existing database, the charac~er is added ~o the database. This learning process con~inues until all ~ the alphanumeric (or other) charac~s and symbols to be 132 a481 ~
used are entered into the database. The system has the capa-bility of storing multiple Stroke characterization databases for systems used by more than one user. The existence of a unique Stroke characterization database for each user has the further advanage of making the writing angle irrelevant. As a result, the invention is adaptable to all handwriting styles and is usable by right-handed and left-handed persons. One feature may desirably be incorporated into the apparatus of the invention to accommodate left-handed and right-handed persons.
This feature is a receptacle (not shown) for the stylus connector on either side of housing 12, so that the stylus 16 may be connected on the left side for left-handed persons and on the right side for right-handed persons.
Fig. 10 also provides an example of the use of "Softkeysl'. In addition to the input line, a variety of Softkeys appear. Each Softkey corresponds to a function that can be performed by the system. In order to execute the funtion, the user merely touches the indicated Point with the pen. The Softkey will then appear in reverse video and the selected function is performed. There are numerous advantages to Softkeys over traditional function keys. Some of the more significant of these are that the user is no longer re~lired to memorize what function key performs what function; the need for keyboard overlays is eliminated: and different Softkeys can be made available (displayed and made operational) at different Points within a program.
Figures llA to llI demonstrates some of the simpli-fications in word processing made possible through the use of this invention. In Fig. llA a standard screen of text is displayed. The user of the keyboardless entry system decides that additional information needs to be added and draws an ~ ~ ~32~L8~
insert symbol (e.g., caret) on the screen at the desired position. A data entry "window" then appears. (Fig. llB).
The text is written in as Handwritten Symbols (Fig. llC), matched (converted to Font Symbols) (Fig. 'ID), and then inserted (Fig. llE). The opera~cor reconsiders the addition and draws a horizontal line through the new material. (Fig. llF).
It is immediately erased. (Fig. llG). Next, the operator decides that a larger right-h~nd margin would be more appropriate for the text. A vertical line is drawn on the screen (Fig. llH) and the margin is automatically adjus-ted (Fig. llI).
A generalized block diagram of the editing process is provided in Fig. 13 and a description of that figure appears hereinbelow.
Figures 12A-12G illustrate how a blank form may be used for a hospital patient. The user of the system first calls up the proper blank form (Fig. 12A). This may be done, for example, by touching an appropriate Softkey. The area where the information, in this case a pulse observation, is to be inserted is touched with the pen (Fig. 12B). After the desired location is highlighted, a "window" appears directly below the space where the observation is to be recorded (Fig.
12C). The nurse then touches the pen on the match box which appears highlighted (Fig. 12D). The software then matches the handwritten input to the corresponding Font Symbols and displayes the result (Fig. 12E). If there is an accurate match, the "insert" block is touched (Fig. 12F), and the new observation is added to the patient's records (Fig. 12G3. This mechanism is clearly appliçable to a wide variety of l'blank forms" in which data is inserted into a form or corrected. For example, it could be used to correct or update financial information in a spreadsheet program. All such applications 132~

are within the purview of this invention. Other information ran be record~ in the same manner.
The reason for using a black background and white letters for ~e newly entered Font Symbols is tc facilitate checking the accuracy of the inputted cha~acter.
Although this is preferable, it is not essential and a white backgrol3nd and black letters is also acceptable.
The abili~ to create a window and input ~ta on the same screen and in physical proxirnity to the text being edited or space for da~ to be input is an important feature of this invention, for it permits ease and speed in the sse of the invention. 1 he user's eye may focus on the space where the data will be inse~d and the abili~ to con~emporaneously display Handwritten Symbols and the co~esponding Fon~ Symbols makes it easy ~o see errors, when the system "misreads" a Handwritten 5ymbol, and then corr~ct errors quicldy and easily.
Referring first to Fig. 5, the overall operation and functioning of the pattern recognition sofhvare will now be described. When the Dperating system calls thP
pattern recognition program7 the program begins in terminal 75 where a number of variables and counters are initialized. The software then proceeds to decision diamond 76 where the prograrn determines if stylus 16 ~Fig. 2) is in contact with input screen 18 (Fig. 2A). The system provides a "pen down" signal, as showll in processing box 78, as well as the X,Y coordinate voltages as loca~ing signals, as described aboYe.
Microcomputer 14 (Fig. 4), using the software according to the pre~sent invention, converts the X,Y coordinate locating sig~lals into Stroke characteristics using programs stored in ROM 54 (Fig. 4), or a separate micr~omputer can do the conv~rsis~n, such as microcontoller M. If a pen down signal is received9 the so~tware proc~dx to processing box 80 where the individual locating signals are combined into "Strokes", a Stroke being -2~-::

132a~81 defined as the Point lo~ting s;gnals produced between a "per. down" signal and a "pen up" signal.
The system then calculates a transforrn~ as described below, for each Point, transforming the Point coordinates from the X,Y cartesian coordinate system to a relational coordinate system. The software nex~ proceeds to processing box 82, where it compares the Stroke with previously entered Strokes accumulated into a database, and determines if the Stroke is represented by a symbol in the databa~e. If a match is found (if the Font Symbol represented by the Strokes is recogniæd), as indicated in decision diarnond 84, microprocessor 50 (Fig. 4) causes the symbol ~o b¢ sent to display s reen 20 (Fig. 4) as indicated in processing bo~ 86. If a match is not ~ound, microprocessor 50 (Fig. 4) causes a mess~ge to be displayed, as indicated in processing box 88, which requests filrther input from stylus on input screen 18 (Fig. 4) by either ~ashing an entry which is close to a match or a non-recognition symbol.
As menboned above, the software compares the S~roke characteristics of each Handw~itten Symbol to data entries previously stored in a database. In a preferred embodiment, the database is arranged into sections of characters or symbols by the number of Strokes needed to make the character or symbol. Within each section, the entries are rando~nly arranged at ~rst, but after use, as explained herein, the most frequently used entries "rise" ~o the top of the database. lt should be noted that each user will have his or her own particular style of wri~ing a lIandwritten Symbol and tha~ ea~h Handwri~ten Symbol may ha~e a number of different variatio~s.
For example, many people write the lower case letter "h" using a single Stroke. They do this by starting the pen on the writing ~ablet at a Po;nt where they wish to place the top of the letter, drawing a vertiçal line downwardly to the base line, then :

~ 325~

without remo~ing the pen from the paper, proc~ding baclc up to the midPoint of the previously drawn vertical line, over to the right and down to the base line when the pen is picked up from the paper. On the other hand, these sample pesple may draw the upper case letter "H" using two Strokes. They do this by drawing the left hand vertical line and horizontal line as is done fior the lower case "H", picking the pen up from the tablet, and then drawing the right hand vertical line. Appendix I displays the data of the Strolse data Points for these two letters as the data is slored in memory aft~} having been generated by an embodiment of the present invention.
As shown in Appendix 1, the letter "h" as drawn at one particular timç by ~;
one user has one S~ke (ns = 1) with 20 Points (np = 20) and x ~nd y coordinate charactenstics for the minimum~ mean and maximum normalized values (1/80th of a line width) 2S follows: -17 and -6; 0 and 18; and 19 an~ 60, respectively. The values in the first vertical column are the Point-t~Point slopes, normalized to 360/256. The values in the second vertical column are the Point-to-Point average vertical positions above the base line, normalized to 1/80 of the line width. A typical line width is about 0.4 inches.
Referring now to Fig. 6, a software hierarchy of programs is depicted. At the top, overseeing the entire ~ ation of computer system 10 (Fig. 1), is an operating ~ystem as indicated by box 90. Applications programs shown in boxes 92 and 94, residing in RAM 56 (Fig. 4) and ROM 4 (Fig. 4) can be executed by mieroprocessor 50 (Fig. 4) under contr~l of the operating systems. When a Handwritten Character is required or is indicated by an interrupt, handwriting recognition so~tware 96 is called. A
first subroutine, indicated in box 98" encodes the X,Y coordinates into Strokes. The characteristics of the Strokes are then defined by a subroutine 1~ fol}ow~d by -2~

::: :: :
:::
::
132~481 comparison of the Strokes with a database that has been loacled from ROM 54 ~Fig. 4) into RAM 56 ~Fug. 4). The omparison is made by a subroutine 102. When the operating system is in the "learning" mode, the database is updated with the new Stroke data and symbols, as indicated in ~,x 104. Similarly, a previously stored document can be edited by applications program 92 by using edit function 94 as callecl by the operator, who provides the instructions as input using the subroutines 98, 100 and 102 of handwAting recognition prograrn 92 ReferIing now als~ to Fig. 7, operating system 90 ~Fig. 6) executes the Handwritten Character recognition software 96 (Fig. 6) by accepting as input the X,Y
coordinate Points, depicted in box 110, of the position of stylus 16 (Fig. 2) on input screen 18 (Fig. 2) and encodes these Points into Strokes as depicted in b~ 112. The program then characterizes the Strokes by some descnption set, such as considenng the length, curvature, slope, and position of the Stroke, as depicted in box l14. In box 116 the best comlparison is then found of the characteriæd Stroke or sequence of Strokes with those in the database. If a sufflciently close match is found, the character is iden~ified in box 118 and the database entry is swapped with the entry above it as shown in box 120.
In this way, the most frequently identified characters will "rise" to the top of the~ database and the overall system peffonnance, ~u measured in time to find a rnatch~ will be increased. If a match is not found, the user can add to ~he bot~om of the database, as indicated in box 122.
With reference l~OW to Figs. 8 and 9, a ~owchart of the computer program to recogni~e a particular Stroke sequence is set forth. The computer program begins in terminal 150 and proceeds to p~ocess the X,Y vol~ages from process;ng box 152, 132~481 :.:
the voltages having been converted to a digital signal. The program then proceeds to decision box 154 where the program determines whether the pen or stylus 16 (Fig. 2) is out of contact with input screen 18. This determination is made by both the X voltage and the Y voltage being zero. If the program determines that the pen is up, then the Stroke is determined as having been completed and the program branches to decision box 156. In decision box 156, the program determines whether there are less than three Points in the Stroke and if so the program branches to decision box 158. In decision box 158, the program determines whether there are zero Points in the Stroke. If there are zero Points in the Stroke, then the ~-program loops back to the beginning of processing box 152 where another set of Points is read. If the Point counter (incre~
- mented in processing box 164) indicates that there are more than zero Points, the progr;am branches to processing box 172.
In processing box 172 the Stroke is identified as a dot and its height above the base line (HABL~ is calculated in processing box 173. From processing box 173 the program proceeds to processing box 171.
However, if the pen down signal is received, the pro-gram branches to processing box 160 where the voltages are scaled to determine the coordinate Point using the following formulas:

X = alVl + bl y = a2v2 ~ b2-The constants al and b~ are scaling param ters that are deter-mined fxom calibrating the input surface of the particular dis-play.

132~4~1 Once the voltages are scaled, the program proceeds to decision diamond 162 where the program determines whether it is an erroneous Point. This is done by comparing the distance between Points and eliminating a Point if the distance is to great (greater than .10 inches is presently used.) On the other hand, a Point is also eliminated if the Points are too close together. Points are presently ~hinned out if they are within .015 inches.
The comparison problem that exists for the first Point is resolved by determining if a Point is the first Point after a pen is down and then that Point is used only to check the next Point which is accepted, assuming that that Point is within the maximum distance (;10 inches).
If the distance between Points is determined as being outside the two criteria, the program drops the Point and branches back to the top of processing box 152 to read another pair of coordinate Point voltages.
On the other hand, if the Points fall within the cri-teria, the program continues to processing box 164 where a Point counter is incremented to keep track of the number of Points. This number is used in decision diamond 156, as mentioned hereinabove. The program then continues to processing box 166 where the Points are smoothed accordlng to any one of a number of formulas. Smoothing is used to minimize noise from digitization, from erratic hand motion and from electronic noise. The simplest smoothing technique is a multiple Point average which results in calculatiny new Points (xj'yj') as follows:

.

~ ~ .
i32~81 n2 ~: x~ xj/(n2 - nl + 1) i=n, And sirnila~ly for Yj. smoothed over Points nl - n2.
Another simple method is called the running weight:ed average method and ~ :
utilizes the following fo~nula:

Xj' = a~ Xj ~ (1 - ~Y) x~

Alpha is a weighting constant that is usually positive (and less ~han one~ and has been used at 0.25. The summa~ions have been taken with n2 minus nl equal to one. A third method involves what is called a spline fit wherein the following fonnula is used:

:
Xj~ --(xj l + 4 xj + xjtl) Any of the foregoing methods can be applied either before or af~r filtering. The filtering is done 50 as to reduce the number of input Points and to space data so that di~erence and/or angle calcula~ions can be made within acceptable :random error bounds. A simple process of thinning a se~uence of Points by e7~cluding the accep~ulce of subsequent Points within a set distance of the preYiously accepted P~ints has been found to be an effec~ve filter.

From process~ng box 166, the program proceeds to processing box 168 where ~e Point is stored in an array that is incremented for each ne~v Point since the last pen dow~ signal. Thus, an addressable ar~y of Points i5 created for each se~uence of Points obtained from a pen down to a pen up signal. This sequence of Points is called a : : :

~2~81 ,:~
Stroke. From proc ssing box 168, the program loops back t~ the top of pr~cessing box 152 where another Point is obtained until a pen up signal ends the Stroke.
In decision diamond 156, a determination was made as to whether there were less than three Points in a Stroke. By dPfinition, if there are three or more Points in a Stroke, the Stroke is a line and not a dot. If there are three or more Points in the Stroke, the program branches to subroutine box 170. In subroutine box 170, discussed in greater detail hereinbelow with resp~ct to Fig. 9, the Stroke is characterized as to its slope and base line height.
As can be seen from the foregoing, the segmentation of the stearn of coordinate Points into a Stroke is based pnma~ily on the determining when stylus 16 is "up" or not in eontact with the surface of input screen 18. Alternatively, a strearn of Points can be segmented to ~orm Strokes on the basis of other considerations. Fsr exampie they can be segmented based upon changes in a loc~lly calculated curvature or upon a large local curvature. L~cal curvature is calculated by the change in distance along the input coordinates divided into the change in slope. This produces radius of curvatu~. When the radius of curvature changes rapidly with respect to distance along the input coord;nates, or if the radius is too small, then a segmentation S~oke is assurned to end, and a new Stroke begun. Further segmentation techniques can look at the relative maximum and minirnum in one or both coordinates and/or the curve crossings in the coordinates. Mowever, these latter two methods have been dete~nined to be less effective.
Characterizing a Stroke reduces the sequence of coordinates defining the Stroke or segment to a set of characteristics that are unique, generalized and minimal. Unique-:

~ ~32~8~
ness refers to both actors that the same characteristics are generated by the same coordinates and that the characteristics are sufficient to regenerate an approximation to the original coordinate se~uence. The term "generalized" is used to mean that the characterization is invariant under such transformations so that the symbols are invariant (e.g., translation and scaling or stretching or small tilt). The scaling of all distances is accomplished by takins~ a ratio of the distance to a writing entry line width.
The minimal set of segme~t characteristics have the following features:
(1) Stroke position: one or more of centroid/average, extent extreme or beginning and ending Points determined relative to the writing entry line, to previous Strokes, or to character extent or center;
(2) Stroke shape is characterized by one or more of average slope, change in slope (~hich is a measure of a~erage curvature) andjor a change in curvature, by sequence of slopes over specific length segments or over fractional 12ngths, or by a gross description of linear direction or circular completion and opening direction;
(33 And Stroke length as characterized ~y distance along the curve and/or the extent extremum along the coordinate system.
In one embodiment of the present invention, position-ing by centroid, extent extremum, and starting and ending coordinates have been successfully used. The Stroke shape is encoded as a sequence of slopes and vertical positions (relative to Stroke centroid). The Stroke length can be approximated by the number of filtered Points. Alternatively, 3 ~ ~ ~ 8 1 - -:
~ ~.

the average curvatu~ can be encoded in total slope change (along with length), change in starting ~ -to er.ding slope or fifflng the slope angle versus length curve: for rate of change of slope angle.
Additional charact~ristics that could be used include location of coordinate relative extrema, curve crossing, cusps, and Stroke direction. A particular method used to determine the unique characteristics is set for~h ~elow.
1. The numerical values of the CAteria for each Stroke of the Handwritten Symbol are detem~ined.
2. The database values for each stroke of the previously learned Handwritten Symbol is determined and sub~acted from the newly determined values respectively.
3. The absolute values of each difference ue scaled, ~o make eaeh of the five measurements reasonably equwalent to the others such as lengths scaled to height bet~een lines.
4. The five thus-determined values are added.
5. A predetermined threshold is used as "goodness" test o~ recognition -- too high a value and Font Symbols are infrequently recognized and too low a value causes Font Symbols to be misidentified. Thresholds of approximately 190()0 are used initially and then switched to approximately 100 for improved recognition. If the threshold is exeeeded, the comparison is discarded and an error message is created and displayed.
6. The database is searched to find a numerical minimum difference. If the minimum difference is below the acceptable threshold for recognition, ~he corres~onding Font Symbol is displayed on the screen or the command is perfvrmed, as ~he case m~y be.

~32~81 -. ;

It has aiso been found that the preferred classification of a Stroke is a continuous one, rather than one that is grossly discrete. For example, determining a slope by angle in 256 directions rather than in 8 is desirable. Other non-continuous classifications can include bars/arches/hooks, number and ciosure of cusps or horizontal or vertical Strokes.
From subroutine 170, the program pro~eeds to processing box 171 where both an individual Stroke and one or more preceding Strokes are compared with a database entry that is stored in RAM 56 (Fig. 4).
This comparison initially begins with three eliminating questions that are asked by ~he program in decision diamonds 174, 176, and 178. In each case, if the databaæ entry is eliminated, the program proceeds to a processing box 180 where the address of the next data entry is received and from which the prograrn loops back to the top of processing box 171. In decision diarnond 174, the first eliminator is asked by seeking if the num'wr of Strolces are different. If the number of Strokes are the ~ne, the prog~un proceeds to decision diamond 175 where the ~v~rage Height Above Base Line (HABL) is calculated and compared with ~he HABL of the data entry.
The entry is eliminated if the difference in the average HABL's is greater than one-half the height of the entry line. From a negative determination in decision diamond 176, the program proceeds to decision diarnond 178 where tne number of Points per Stroke are compared and the database entry is eliminated if the d}fference in number of Points is greater than ten. Ihis determina}ion varies from that made in decision diamond 174 because it is concerned only with ,he number of Points for each Stroke. However, in decision diamond 174, certain letters, such as the capital letters 1~ and "A", have more than one Stroke pe7 letter.

3 2 ~ ~ 8 1 . .
If a data entry is not eliminated by decision diamond 178, then the program proceeds to processing box 182 where the program calculates a gauge to be used to determine the closeness of the match between the selected en~y in the database and the d~wn Stroke. A
presently preferred gauge is the sum of the absolute values of ~e differences between ~he Stroke va1ues and the database entry values of:
a) distances or lengths in units of l/80th of the line height (e.g., space 26, Fig.
2); and b) the slopes in units of l/256th o~ 360 over ~11 the Points along the diagonal of tlle comparison matrix.
Altematively, Dynamic Programming Techniques can be used to optimize the comparison using off-diagonal elements as well.
From pro~ssing box 182, the program proceeds to decision diamond 186 where a match is detennined In actuality, a match is determined by (the applica~ion of an arbitrary) gauge (ma~cimum allowable vanance), which is the sum of absolute values of the differences between the entered Stroke characterization and that of the stored database entry. In processing box 1837 the lower of the present gauge and the previous lower g~wge is saved as ~he best ma~ch~ The program then goes to decision diamond 184 where a determination is made whether the present entry is the last database entry. If it is not, the program branches to processing box 180 where the next entry is selected. If i~ is the last entry, the prograrn proceeds to d~cision diarnond 185 where a detennination of a match is made on the basis of the gauge being below a predetennined threshold. This threshold is set by the user based on experience with ~he sys~em.
If no match is obtained, the program branches to decision diamond 188 where a determination is made whether all Strokes have been checked. If the las~ Stroke has been checked, then the present Strske is compared in sequence wiLh a previous Stroke to all two Stroke entries. As in the comparison with all one Stroke dictionary e.r.tries, ~he best fit comparison for all entered Strokes is the rec~gnized symbol or sequence of symbols.
HoweYer, if the last Stroke has been read and there still is not a match, then the program proceeds to processing box 190 where a question is displayed on display screen 20 asking the user if a new Font Symbol shou~d be added to the database. The user responds and ~hat response is used in decision diamond 192. Fither the Stroke sequence is added to the data~ase in p~ocessing box 194 and the program branches back to the top of processing bo~ 152, or the program branches immediately to the top of proeessing box 152.
On the othel hand, if a match is de~eTmined in d~ision diamond 186, the program branches to processin~ box 195 where the prograrn shuffles the database by interchanging the serial location of the matched entry with the entry above it. The program then pr~eeds to processing box 196 where the program zeros the Point counter and the increment counter. The program next proceeds to processing box 198 where the matched and characteriz~ Stroke or Strokes are displayed by the computer as the identified Font Symbol. This dis~lay is located at the position in which ~he ently was made on input screen 18 (Fig. 23.
From processing box 198, the program proceeds to px~essi~3g ~x 200 where the program can act on any commands which it has interpreted. An alternative charactenzation of the Stroke uses the Points themselves rather than the length, scope, curvature and pOSitiOIl.

-3~

~ ~ i l 32~481 With reference now to Fig. g, this Stroke characteriza-tion is depicted in greater detail. Stroke characterization ,: :
subroutine 170 essentially performs a mathematical transforma-tion of each Point on a Point-by-Point basis to transform the Points from an X,Y Cartesian coordinate system to one in which the coordinates are the normalized slope of each Point and the normalized height of each Point above the base line (HABL).
Subroutine 170 first calculates the Point to Point slope in processing box 220 and then calculates the height of each Point above the base line in processing box 222. The slope and HABL of each Point are then normalized respectively to 1/256th of 2 Pi and to l/80th of the width of the entry line in processing box 224. From processing box 224, the system pro-c~eds to processing box 226 where the calculated normalized values for each Point are stored in an addressable array. The subroutine then returns to the program through terminal 228.
When the comparison is made between each Stroke and the stored values, the comparison is made by the normaliæed Point slope and Point hei~ht above base line. As mentioned above, a match is determined by an arbitrary gauge which is the sum of absolute values of the differences between the written Stroke and the stored or dictionary Stroke. The system learns by adding new Strokes to the dictionary database. Once the database fills up, those Font Symbols that are inreyuently used are replaced by new entries.
In a working embodiment of the present invention, the algorithm successfully identified upper and lower cas~e letters and numbers when written discretely from one another. For Handwritten Symbols that are written such that they are continuous, direct extrapolation would require searching a database sequentially for one, two, three, etc. Stroke ~ymbols 1 3 2 ~ 4 8 1 :~ ~
and looking for the best fit. Upon identification of a Stroke fit, a "new" letter is tenatively recognized, except that the next few Strokes are analyzed to check if they change the previous symbol for a better fit. For example, two Strokes that have been identified as "ones" would be combined and changed to the capital letter "H" once a cross bar was identified.
The system design demonstrated by Figs. 7 to 9 could easily be coded by one with ordinary skill in the art of computer programming into almost any computer language. The source code listings for one application program utilizing the disclosed invention is included as Appendix II. The software in Appendix II is written in Microsoft Basic, a common computer language available for ~irtually all microcomputers and operating systems. The program is a complete text editing demonstration, which takes advantage of many of the key features of this invention and shows the improvements that can be made upon traditional word processing systems through the utilization of this invention.
Program lines 2600 to 4000 contain the character recognition subroutine which includes the software code necessary to get X and Y coordinates. This section of the program corresponds to Fig. 8.
Program lines 2600 to 2699 make up a subroutine designed to obtain the X and Y coordinates of a given Point.
This code corresponds to boxes 152, 154, 160, 162, 164, 166 and 168 of Fig. 8.
I Program lines 3000 to 3339 constitute a Point and Stroke analysis and characterization routine e~bodying boxes 156, 158, 170, 172 and 173 of Fig. 8.

.

3 2 ~ 4 ~ 1 :
~ . .
Program lines 3700 to 3790 make up a subroutine designed to compare the analyzed Strokes to a Stroke database.
These program lines embody boxes 171 to 184 of Fig. 8.
Program lines 3810 to 3980 make up a subroutine which is designed to learn a new character. This code embodies boxes 186, 188, 190, 192 and 194 of Fig. 8.
Program lines 3060 to 3273 make up a subroutine designed for Stroke characterization purposes. This section of the code corresponds to Fig. 9.
Program lines 3060 to 3095 are used to calculate Point-to-Point slopes and embody box 220.
Program lines 3058, 3241 and 3262 are used to calculate a height above baseline (HABL) and correspond to box 222 of Fig. 9.
Programs lines 3253, 3270-3273 are used to normalize the Point height and slope and correspond to box 224 of Fig. 9.
Program line 3253 is used to store the height above baseline and embodies box 226 of Fig. 9.
The foregoing program can be stored in the memory of a microcomputer of microprocessor with a re~uirement of approximately 25~ of machine memory, so that it can be seen that the use of the program does not use up a lot of expensive memory and is relatively fast in executing the program's operation. If the program is written in a language other than Basic, requiring less memory, such as assembly language, the size of the program can be made smaller.
Boxes 195 to 200 of Fig. 8 appear in logical places throughout the code.
A dictionary of the variables of the relevant code section is included as Appendix III.
With reference now to Fig. 13, a flowchart for the editing software ~"Editor") demonstrated by Figs. llA to llI

:
~ ~ ~: 132~481 . .
and described above is depicted. Once the Editor is loaded ~- into the system (box 229~, control of the screen is returned to the system. The system then proceeds in the normal manner described above to acquire Points and display them (box 230~, convert the Points into Strokes (box 231), characterize each Stroke (box 232), and attempt to match the Stroke or Strokes with the database (box 233). In processing box 234, the system sends each Handwritten Symbol to the Editor to interpret and execute a command if necessary. At decision diamond 235, the Editor determines whether the Handwritten Symbol is an Editing Symbol or a Font Symbol. If the character is determined to be an Editing Symbol, the Editor proceeds to processing box 236 where it determines which Editing Symbol has been entered and executes the Editing Function. If the character is determined not to be an Editing Symbol, then the alphanumeric character corresponding to the handwritten entry is displayed at pro-cessing box 237. In an alternate configur~tion of the ~ditor, Font Symbols will only be accepted when the Editor is in the "Insert Mode." This structure insures that each Font Symbol is verified before being added to a document.
The Editor uses a variety of symbols designed to make editing on the system similar to, but much more efficient than, traditional editing with pencil and paper. These functions include, but are not limited to:
DELETE symbol - " " A horizontal line drawn through a character or characters. The Editor will remove the underlying characters and reformat the text.
ADJUST MARGINS symbol - "¦" A vertical line longer then the height of one line on the display. The Editor will adjust the margin to the indicated position and reformat the text.

~ 132~4~1 INSERT symbol - "~" A caret drawn at the Point where text is to be added. The Editor displays an input writing line (Fig. 118) and when input is recognized inserts it into the text.
MAR~ TEXT symbols - "~' and "' A less than and greater than symbol drawn at the beginniny and end of a block of text. The marked text is displayed in reverse video and then special block functions can be performed.
DELETE MARKED TEXT - A delete s~mbol drawn within marked text will erase the marked text and reformat.
MOVE MARKED TEXT - An insert symbol drawn anywhere within the text moves the marked text to the indicated position, deletes it from its origional position and reformats the text.
REPLACE ~AR~ED TEXT An insert symbol drawn within the marked text displays an input line and replaces the marked text with the inputted text.
The Editing Symbols described above can be changed to the particular Editin~ Symbols preferred by each user, thereby customizing the Editor and preventing new users from having to learn unfamiliar Editing Symbols.
Further modifications and enhancements to the present invention would be obvious to those skilled in the art. For example, the common characteristics of each Font Symbol could be extracted and organized into a synthetic symbol. The synthetic symbol's characteristics could then be exaggerated to maximize their variance from all other synthetic symbols~ This would create a very compact, optimal database. On the other hand, as an example, a database created by the described preferred embodiment of the invention usually results in two to three different characterizations for each symbol.

:: : `:~
~: ~ 132~48~

~ The invention has numerous useful applications, :. ~
almost without limitation. The most obvious applications are text editing and filling out and modifying forms. Some of the many other applications that may not come to mind as readily are writing in languages utilizing large numbers of symbols like Japanese or Chinese; writing in Arabic and similar lan-guages made up of a limited number of complex symbols; writing chemical equations, including those involving organic compounds; writing music ~a "window" with five par~llel lines can be provided for musical applications); writing symbols and codes for graphic manipulation of data, including the transfer of graphic data to a spreadsheet; in education, as where predetermined questions are presented on the screens and the answers written in long-hand; as in teaching mathematics, as when numbers are manually inserted in equations and the equation analyzed to determine the result using those numbers;
in CA3/CAM applications involving symbols, geometric shapes and the like.
Although the invention has been described in terms of a selected preferred embodiment encompassing the apparatus and methods aspects of a keyboardless oomputer system, the invention should not be deemed limited thereto, since other embodiments and modifications will readily occur to one skilled in the art.

:
~32~81 APPEND I X I

'h' (1) ns = l x = (-17.Ø.19) y = (-6..18..60) 1) np = 20 x = ( -17. Ø .19) y ~ ( -6. .18. .60) 5, 42 _57, 34 -85, 26 -71, 19 -76, 10 -64, 3 - 89, - 3 -72, _9 -85, -17 ~72, -24 47, -17 56, -11 43, - 3 39, 3 ll, 7 _9, 5 -57, -3 -71, -11 -71, -1~
'H' (1) ns = 2 x = (-27.Ø.37) y = (-20..18..Sl) 1) np = 14 x = (-27..-12..-2~ y = (-20..22..61) _9, 37 4, 38 -39, 32 -48, 25 -58, 16 -71, 8 -72, 2 - 64, - 4 - 89, - 11 -72, -17 -80, -24 -89, -30 -80, -36 2) np 20 x = (-21..10..37) y = (-15..16..59) 27, 43 -80, 37 -71, 29 -98, 23 -80, 16 -78, 8 -85, -89, -6 -80, -12 -B0, -18 -64, -25 -64, 31 48, -25 56, -18 48, - 12 64, -6 89, -124, 0 124, -2 - ~ 3 2 ~
~- ~ APPENDIX II
-.

1 REM Z SERIES COPYWRITE: LINUS TECHNOLOGIES INCORPORATED, RESTON, VA., 7/30/85 10 DEFINT A-Y : REM all integers excep~ z 20 DIM X(2000),Y(2000),D(9, 800),DN~300),DC(300),SX( 80),SY( 80),SL( 80),SC( 80),SA( 80),SXX( 80),SXN( B0),SYX( 80),SYN( 80),SNO(80),MTITL$(20),A$(1500),LL(24),AS$(200),SLET(80),DBC(9,10),ASTRT(80),AEND(80) 25 PRINT FRE(O) 30 PRINT "Z SERIES COPYWRITE: LINUS TECHNOLOGIES INCORPORATED, RESTON, VA., 7/30/85"
IMARGN=5 : IMARGX=62 : JTOP=1 : JBTM=15 : JMENU=~60 :CR$= n ^ n KYBD=0: LHT=16 :SXTT=4: JTX=0: ACPT=1000 60 LHT4=LHT\4 :LHT3=LHT\3 :LHT5=LHT\5 :LHT2=LHT\2 70 PRINT "PLEASE INPUT PEN SWITCH...-1 TO RERUN, 0 TO RUN, 1 TO RUN & STORE": INPUT SWTPN
IF SWTPN > -1 THEN GOSUB 10700 :REM TOUCH TECH SCREEN IN ASCII @ 9600 80 PRINT "PLEASE INPUT DEBUG ...-5 TO 5 n: INPUT DBUG
85 PRINT ~PLEASE INPUT ACCEPTANCE CRITERIA...10 TO 1000 ~: INPUT ACPT
90 PRINT "PLEASE INPUT EDIT/LEARN SWITCH...1 TO EDIT": INPUT EDLN
92 PRINT ~PLEASE INPUT KEYBOARD SWITCH...0 FOR ~EYS, 1 FOR MENU n: INPUT KYBD
95 PRINT "PL~ASE INPUT RESTART SWITCH...1 TO RESTART WITX STORE~ DATA BASE~: INPUT RESTRT
97 IFAVE-0 :IF SWTPN=-1 THEN IFAVE=0 :REM PRINT "PLEASE INPUT AVERAGING SWITCH...1 TO READ & AVERAGE, 2 TO AVERAGE INPUT": INPUT IFAVE
100 KEY OFF :SCREEN 2 :CLS
120 IF RESTRT = 1 THEN GOSUB 12700 130 IF EDLN = t THEN GOSUB 12100 : REM READ IN TEXT
140 IF EDLN = 1 THEN GOSUB 600 : REM PRINT TEXT
150 IF SWTPN = 1 THEN GOSUB 7200 151 IF SWTPN = -1 THEN GOSUB 7000 170 IF EDLN <> 1 THEN GOSUB 6100 180 IF EDLN <> 1 THEN GOSUB 1250 205 LINY=0 210 IF SWTPN = -1 THEN GOSUB 7100 ELSE GOSUB 2600 :REM TOUCH TECH SCREEN IN ASCII @ 9600 211 IF SWTPN =1 THEN GOSUB 7300 220 REM RECOGNIZE SYM~OLS
221 IF NP > 2000 THEN LOCATE 23,1: PRINT "TOO MANY POINTS" : STOP
222 IF NP < 4 THEN GOTO 200 230 GOSUB 3000 :GOSUB 3400 :REM ~~ <>~ P~E
240 ON NCH~R GOTO 1200,1300,1700,6200,6700,6500,6600,12500,6900,200 :REM DELETE,MOVE,FORMAT,INSERT,WRITE OVER,REMOVE,PARAGRAPH,INSERT C~AR~CTER,END

605 LOCATE 23,20: PRINT " ", -~
610 I=II : J=JJ : REM INITIAL DISPLAY POINT FOR NC1 620 FOR K=NC1 TO NC
630 IF A$~K) <> CR$ TH~N GOTO 660 6qo LOCATE J,I : PRINT ~ n : I=I~1 : IF I < 81 GOTO 640 650 J=3+1 : I=IMARGN : LL(J)=K : GOTO 740 660 IF I< IMARGX THEN GOTO 670 ELSE IF A$IK~- n n GOTO 690 670 IF J> JBTM THEN LOCATE 21,20: PRINT ~READYU, :RETURN
680 LOCATE J,I : IF I=IN THEN GOTO 710 ELSE PRINT A$tK) : I=I+1 : GCTO 740 690 LOCATE J,I : PRINT ~ IF I< 81 ~OTO 690 700 J=J+1 : I=IMARGN : LLtJ)=K+1 : G9TO 740 710 IF A$tK) <> " " THEN GOTO 730 720 IF LL(3~=K GOTO 740 730 I=I+1 : PRINT A$(K) 740 IF I> IMARGX+10 THEN GOTO 690 ELSE NEXT K
750 IF J> JTX THEN GOTO 790 760 JS=J
765 LOCATE J,I : PRINT " ": I=I+1: IF I< 81 GOTO 765 770 J=J~1 : I=IMARGN: IF J > JTX ~HEN GOTO 780 ELSE 50TO 765 2 ~ 4 8 1 ,~

; 7~0 J=JS
790 JTX=J : LOCATE 23,20: PRINT "READY", :RETURN

1205 XX=~XX(1): XN=SXN(1): YX=SYX(1): YN=SYN(1) 1206 IF NSTRK=l GOTO 1220 1210 FOR L=2 TO NSTRK
1212 IF XX < SXX(L~ THEN XX=SXX( L) 1214 IF XN > SXN(L) THEN XN=SXN(L) 1216 IF YX < SYX(L) THEN YX=SYX(L) 1218 IF YN > SYN(L) THEN YN=SYN(L) 1220 IN=IMARGN
1225 I=INT(XX/8)+1 : IF I < IN THEN I=IN
1230 J=INT(YX/8)+1 : ML=LL~J) :M2=ML+I-IN : IF A$(ML)=~ ~ THEN M2=M2+1 1231 IF A$/ML)=CR$ THEN M2=M2+1 1232 I=INT(XN/8)+1 : IF I < IN THEN I=IN
1234 J=INT(YN/8)+1 : ML=LL(J) :M1=ML+I-IN : IF A$(ML)=n n THEN Ml=Ml+1 1240 IF A$(ML)=CR$ THEN M1=Ml+l 1250 MD=M2-M1~1: IF MD < O THEN MD=M1-M2+1 : Ml=M2 1260 FOR M=Ml TO NC : A$ ( M ) =A$ (M+MD) : IF M+MD=NC THEN GOTO 1270 ELSE NEXT M
1270 FOR M=NC-MD+1 TO NC :A$(M)= ~ n : NEXT M
1280 II=I: JJ=J: NC1=~1 : GOSUB 600 1290 NC=NC MD : GOTO 200 1305 IN=IMARGN
1~10 XX=SXX(1): XN=SXN(11: YX=SYXI1): YN=SYN(1) 1320 XP=(XN+XX)/2: YP=(YN+YX)/2 :REM AVE BRACKET POSITION
1330 I=INT(XP~8)+1: J=INT(YP/8)+1:REM CONVERT X,Y TO I,J
1340 ML=LL(J~: M1=ML+I-IN :REM CALC A ARRAY INDEX OF LETTER AT l,J
1 1350 IF A$(ML)=" " THEN Ml=Ml+l l~ 1360 IF A$(ML)=CR$ THEN Ml=Ml+1 I 1390 XX=SXX(2): XN=SXN(2): YX=SYX(2): YN=SYN(2) : 1400 XP=~XN+XX)/2: YP=IYN+YX)/2 :REM AVE BRACKET POSITION
1410 I=INT~XP/8)+1: J=INT(YPj8)+1:REM CONVERT X,Y TO I,J
1420 ML=LL~J): M2=ML+I-IN :REM CALC A ARRAY INDEX OF LETTER AT I,J
1 ~ 1430 IF A$1ML)=" " THEN M2=M2+1 ~:~
¦ 1440 IF A$~ML)=CR$ THEN M2=M2+1 1 1450 M3=0:REM INITIATE COUNTER ~
1 1460 FOR M=M1 TO M2 :REM LOOP OVER PORTION CUT ~:
1470 M3=M3+1: REM INCREMENT COUNTER
1480 AS$~M3)=A$~M) :NEXT M :REM COPY CUT TEXT :~
1 1490 XX=SXX~3): XN=SXN(3): YX=SYX(3): YN=SYN(3l ~:~
1 1500 REM INSERT WITH M3 LETTERS STORED IN AS$ & xx,x~,yx,yn :~ .
1520 XP=(XN+XX)/2: YP=IYN~YX)/2 :REM A~E BRACKET POSITION :~
1530 I=INTtXP/8)+1: J=INT(YP/8)+1:REM CONVERT X,Y TO I,J
1540 ML=LL(J): M3=ML+I-IMARGN :REM CALC A ARRAY INDEX OF LETTER AT I,J ~.
1550 IF A$1ML)=n n THEN M3=M3~1 1560 IF A$~ML~=CR$ THEN M3=M3+1 1570 MD=M2-Ml~l : IF MD > O THEN GOTO 1S80 ELSE GOTO 200 1580 FOR M=Ml TO NC : REM LOOP OVER A$ M RAY POSITIONS TO BE SHIFTED
1590 A$/M~=A$(M~MD) : REM SHIFT A$ ARRAY LETTERS
~ 1600 IF MIMD = NC THEN GOTO 16 15 ELSE NEXT M : REM STOP AT END OF ARRAYzNC
} 1610 IF M3 > M2 THEN M3=M3-MD :REM OFF SET INSERTION POINT TO ACCOUNT ~OR DELETI
~3 ON
:~ 1620 FOR M=NC-MD TO M3 STEP -1 : REM SPRED ARRAY TO MAKE ROOM FOR INSERTION, 1630 A$(M~MD)=A$1MI ~REM MOVE LETTERS
`~ 1640 NEXT M
1650 FOR M=l TO MD :REM LOOP OVER CHARAcTERs ` 1660 A$(M3+M-l)=AS$~M) :REM INSERT LETTERS

1680 CLS: II=IMARGN: JJ=JTOP: NCl=l : GOSUB 600 ~.
:' .

~` ~
1 3 2 a 4 8 1 , , .
1720 XP=(SXN(L)+SXXlL))\2 :REM AVE BRACKET POSITION
1730 I=XP\8+1 :REM CONVERT X TO I
1740 IF ABS(I-IMARGN) <ABS(I-IMARGX) THEN IMARGN=I ELS~ IMARGX=I
1750 CLS: II=IMARGN: JJ=JTOP: NC1=1 : GOSU8 600 2600 REM TT ACQUIRE POINTS IN ASCII @ 9500 WITH TIME OUT
2603 M=20 2605 IF LOC(2) > 0 THEN IPUT$=INPUT$(1,2) : GOTO 2605 2506 PRINT ~2,"G" :N=0 2610 IF LOC(2) < 40 THEN GOTO 2610 2620 NU=0: INPUT #2,XP,YP :INPUT #2,XP,YP :INPUT #2,XPA,YPA :INPUT #2,XP0,YP0 2630 N=N+1- XPA=(XPA+XP0)\2: YPA=(YPA+YP0)\2: XP0=XPA: YP0=YPA: X(N)=XPA: Y(N)=Y
2640 INPUT #2,XP,YP
2653 XPA=(XP+3*XPA)\4: YPA=(YP+3*YPA)\4 2657 IF ABS(XPA-XP0)+ABS(YPA-YP0) < 3 THEN GOTO 2672 2660 I=32~XPA\AX+BX:J=32*YPA\AY+BY:PSET(I,J) 2670 N=N11 : X(N)=XPA :Y(N)=YPA: XP0=XPA: YP0=YPA
2672 IF LOCl2) > 9 THEN GOTO 2640 2675 MM=0 2680 MM=MM+1: IF LOC(2) > 9 THEN GOTO 2640 ELSE IF MM S M THEN GOTO 2680 2685 X(N)=-X~N): IF X(N) = 0 THEN X~N)=-1 2690 IF LOC(2) > 39 THEN GOTO 2620 ELSE NU=NU~1 :IF NU < 4000 THEN GOTO 2690 2695 PRINT #2,"S": NP=N
2696 IF DEBUG <> 0 THEN ~OCATE 20,2 :PRINT "NP=",NP
2697 IF IFAVE=2 THEN GOSUB 4200 2698 IF DEBUG <> 0 THEN LOCATE 20,12 :PRINT NP

3005 REM GOSUB 4200 :REM 2 POINT AVERAGE POINTS
30~10 A1=0: A~=0: DA1=0: DA2=0: SEND=0: ZX=0: ZY=0: ZA=0: ZDA=0: ZL=0: NSP=0 :3015 NSTRK-0: XX=ABS(X(1)): XN=XX: YX=Y(1): YN=YX: M1=1: M2=1: M3=2: NLONG=0 3020 FOR M=2 TO NP
:3025 IF X(M) < 0 THEN SEND=2 :X(M)=-X(M) 3030 IF M > M1 GOTO 3035 ELSE 3391 3035 IF X(M1) ~ 0 THEN M1=M: GOTO 3391 3040 DX=X(M)-X(M1): DY=Y(M)-Y(M1): ADX=ABS(DX): ADY=ABS(DY): DS=ADX+ADY
3043 IF AY > 0 THEN DY=-DY
3044 IF DS < 3 THEN GOTO 3391 3052 IF X(M) < XN THEN XN=X(M) 3053 IF X(M) > XX THEN XX=X(M) ; ::
3054 IF Y(M) < YN THEN YN=Y(M) :
3055 IF Y(M) > YX THEN YX=Y(M) 3058 ZX=ZX+X(M)*DS: ZY=ZY+Y(M)*DS: ZL=ZL+DS: NSP=NSP+1 3060 IF ADX < ADY THEN GOTO 3080 :REM ENCODE ANGLE 0-255 l-n256 3070 IF DX > 0 THEN A1=64-(32*DY)\DX ELSE A1=192-(32*DY)~DX

3080 IF DY S 0 THEN A1= ~32~DX)\DY ELSE A1=128+t32*DX)~DY
3085 IF NSP>M2 THEN GOTO 3090 30~6 IF A1<0 THEN A1=A1+256 3087 ZA=ZA+A1~DS

3090 IF A1-A2 ~ -127 THEN A1=A1+256 : GOTO 3090 3095 IF A1-A2 > 128 THEN A1=A1-256 : GOTO 3095 3100 ZA=~A+A1*DS
3110 DA1=A1-A2 3115 ZDA=ZDA+DA1 3120 IF NSP > M3 THEN ADA=(DA2+ADA)/2 ELSE ADA=DA1 : AST~TlNSTRK~1)=(A1+A2~2 3130 I~ NSP = M3+1 T~EN ASTRT(NSTRK~1)=(A1-~A2)~2 3140 IF ABS(DA1-ADA) > 80 THEN SEND=1 31S0 IF ABS(DA1) > 64 THEN SEND=1 3190 IF SEN~=0 THEN GOTO 3300 , .

,., :
:.
~; -46--.
~, `~:
~ - ~32~481 .
i~ .
3205 IF SEND = 1 THEN GOTO 3220 3206 X(M)=-X(M) 3208 SEND=0: SZL=ZL: SZL=32*SZL\AY: IF SZL < 0 THEN SZL=-SZL
3209 IF NSP < 3 THEN GOTO 3210 ELSE IF SZL > 2 THEN Ml=M+1: GOTO 3250 3210 IF NSTRR > 0 THEN IF X(SNO(NSTRK)~ > 0 THEN X(SNO(NSTRK))=-X(SNO(NSTRK)) 3212 M1=M+1 3220 SEND=0: SZL=ZL-DS: SZL=32*SZL\AY: IF SZL < 0 THEN SZL=-SZL
3226 IF NSP < 4 THEN GOTO 3300 ELSE IF SZL < LHT5 THEN GOTO 3300 3230 M1=M
3240 ZX=ZX-X(M)~DS
3241 ZY=ZY-Y(M)*DS
3242 ZL-ZL-DS: ZA=ZA-A1*DS: ZDA-ZDA-DA1 3243 NSP=NSP-1 3250 NSTRK=NSTRK+1 3253 SL(NSTRK)=50*SZL\LHT: AEND(NSTRK)=(A3+A4)\2: SC(NSTRK)=ZDA : AZA=ZA/ZL
3254 IF AZA > 255 THEN AZA=AZA-256 : GOTO 3254 :REM USE 128 HERE FOR DIRECTION INDEPENDENCE
3256 IF AZA < 0 THEN AZA=AZA+256 : GOTO 3256 3260 SX(NSTRK~=ZX/ZL: SX(NSTRK)=32*SX~NSTRK)\AX+BX
3262 SY(NSTRK)=ZY/ZL: SY(NSTRK)=32*SY~NSTRK)\AY+BY
3264 SA~NSTRK)=AZA
3270 SXX~NSTRK)=32~XX\AX+BX: SXN~N5TRK)=32*XN\AX+BX: SNOtNSTRK)=M
3272 IF AY < O THEN SYN~NSTRK)=32*YX\AY~BY: SYX~NSTRX)=32*YN\AY~BY : GOTO 3280 3273 SYX(NSTRK)=32*YX\AY+BY: SYNINSTRK)=32*YN\AY+BY
3280 IF DBUG > 3 THEN LPRINT USING " ##"iM,NSP,X~M),Y(M),ZL,ZA,Al,DA1,ADA,ZDA,(AlIA2+A3+A4)\4 ELSE IF DBUG < ~3 THEN PRINT USING n ##n;M,NSP,X(M),Y~M~,ZL,ZA,Al,DA1,ADA,ZDA,~A11A2+A3+A4)\4 3281 IF DBUG > 2 THEN LPRINT n SL,SA,SC,AS,AE n ,SL(NSTRR) SA(NSTRK) SC(NSTRK) ASTR
T(NSTRK) AEND~NSTRK) ELSE IF DBUG < -2 THEN PRINT ~SL,SA~SC,AS~AE~SL(NSTRK) SA(NSTRK) SC(NSTRK) ASTRT(NSTRK) AEND(NSTRK) ~-~
3285 Al=0: A2=0: DAl.=0: DA2=0:DS2=0:DSl=0:SEND=0: ZX=0: ZY=0: ZA=0: ZDA=0: ZL=03290~XX=ABS(X(Ml)): XN=XX :YX=Y(Ml): YN=YX: NLONG=0 :NSP=0 3295:GOTO 3391 3300 REM FINISH LOOP ::
3310 M1=M
3320 DA3=DA2: DA2=DA1: DS2=DSl: DSl =DS: A4=A3: A3=A2: A2=Al `~
3390 IF DBUG > 3 THEN LPRINT USING " ##";M,NSP,X(M),Y~M),ZL,ZA,A1,DA1 ~ADA~ZDA
,(A1 +A2~A3~A4 )\4 ELSE IF DBUG < -3 THEN PRINT USING "#~###";M,NSP,X(M),Y(M),ZL, ZA~Al~DAl~ADA~ZDA~(A1+A2+A3+A4)\4 :.

3392 IF DBUG > 1 THEN LPRINT n I NO X Y L A C XX XN
X YN ST ND"
3393 IF DBUG ~ ~l THEN LOCATE 9~1 :PRINT n I NO X Y L A C
XX XN YX YN ST ND~
3394 IF DBUG < ~1 THEN LOCATE 10~1 :FOR I=l TO NSTRX:P~INT USING ~ #n;I,SNO(ISX(I)~SY(I)~SL(I)~SA(I)~SC(I)~SXX(I)~SXN(I)~SYX(I)~SYN(I~ASTRT(I)~AEND(I) :NE
XT I
3395 IF DBUG > 1 THEN FOR I=1 TO NSTRK: LPRINT USING ~ #~;I,SNO(I),SX~I),SY~I),SL(I),SA~I),SC~I),SXX~I),SXn~I~,SYX~I),SYN~l),ASTRT~I),AEND~ NEXT I
3396 IF NSTRK ~ 1 THEN GOSUB 4000 ELSE GOTO 3399 3397 IF DBUG < -1 THEN FOR I-1 TO NSTRK:PRINT USING ~ #n; I,SNO~I),SXtI),SY~I) ,SL~I),SA~I~,SClI~,SXXlI~,SXNll),SYX~I),SYN~I~,ASTRT~I),AEND~ EXT I
3398 IF DBUG > 1 THEN FOR I=1 TO NSTRX: LPRINT USING ~###~#";I,SNO~I),SX~I),SY~I~,SL~I~,SA~I),SC~I~,SXX~I~,SXNlI),SYX~I),SYN~I~,ASTRTtIl,AEND~ NEXT I

3410 FOR L=1 TO NSTRK
3412 A1=~SA~L)+32)\64: IF A1 > 3 THEN Al'0 3416 IF A1 = O THEN IF SL~L) > 100 THEN NCHAR=3: RETURN: ~E~ VERTICAL
3418 IF Al = 1 THEN IF SL~L~ > 60 THEN NCHAR=l: RF-TURN: REM HORIZONTAL
3420 IF Al = 2 THEN IF SL~L) > 100 THEN NCHAR=3: RETURN: REM VERTICAL
3422 IF Al = 3 THEN IF SL~L) > 60 THEN NCHAR=l: RETURN: RE~ HORIZONTAL

.
, .
~' ~47~

:
~ 3 ~ ~ ~ 8 1 3510 ED=l :GOSUB 3600 :ED =0 3515 IF NLET > 0 THEN GOTO 3530 3520 NCHAR=10: LOCATE 20,1: PRINT "TRY AGAIN" :RETURN
3530 IF CS$ = "-" THEN NCHAR =l :RETURN
3532 IF NLET = 3 THEN IF CS$ = "^" THEN NCHAR=2 :RETURN
3536 IF CSi$ = " " THEN NCHAR=4 :RETURN
3538 IF CS$ = "\" THEN NCHAR=9 :RETURN
3540 IF CS$ = "P" THEN NCHAR=7 :RETURN
3542 IF CS$ = "E" THEN NCHAR=8 :RETURN
3544 IF CS$ = n/" THEN NCHAR=6 :RETURN
3546 IF NLET= 1 THEN NCHAR=5 :RETURN

3602 IF DBUG > 4 THEN LPRINT USING " ##"; SXX(1),SXNIl),SYX(11,SYN~l),LHT4 3603 SLET(1)=1: NLET=1: IF NSTRK=1 THEN GOTO 3650 3605 FOR L=2 TO NSTiRK
3606 IF D~UG > 4 THEN LPRINT USING " ##"; SXX(T~ ,SXN(L),SYX(I,),SYN(L) 3607 ICONT=0 3610 FOR L1=1 TO 2 : IF L > 2 THEN GOTO 3615 ELSE IF L1=2 GOTO '2635 3615 IF SXX(L-L1) > SXX(L) THEN GOTO 3630 ELSE IF ~SXX(L-L1)+LHT4) < SXN~L) THEN GOTO 3635 3620 IF ABS((SYX(L)+SYN(L))-(SYX(L-L1)+SYN(L-L1))) > LHT THEN GOTO 3635 3629 ICONT=Ll :GOTO 3635 3630 IF SXN(L-L1) > SXX(L)+LHT4 THEN GOTO 3635 ELSE GOTO 3620 3640 IF ICONT=0 THEN NLET=NLET+l :SLET(L)=NLET: GOTO 3649 36i5 NLET=SLETIL-ICONT} : SLET(L)=NLET :SLET(L-1)=NLET
3646 IF DBUG > 3 THEN LPRINT "L,NLET,SL~T",L,NLET,SLET(L-1),SLET(L-2 3652 IF ED=1 THEN ZLINY=0: FOR LMN=l TO NSTRK : ZLINY=ZLINY+SYX-(LMN)ISYN(LMN): N ~ :
EXT LMN : LINY=ZLINY/NSTRK :LINY=(l+LINY\16)*8+4 :IF DBUG ~ O THEN LPRINT ~LINY=",LINY ELSE IF DBUG < 0 THEN LOCATE 22~1 :PRINT "LINY=",LINY
3655 MCHR-l: NST=0 XX=-l: XN=1000: XXl=-lOO :YX=-1 :YN=1000 :YX1'-100 3656 FOR LSTRK=1 TO NSTRK+1 3657 LST=LSTRK :IF LSTRK = NSTRK+l THEN GOTO 3659 3658 IF SLET(LSTRK) = MCHR THEN NST=NST~l: GOTO 3690 3659 IF NST > 10 THEN LOCATE 23,1 : PRINT "TOO MANY STROKES", :STOP
3660 FOR M=l TO NST :LMN=LST-NST~M-1 3661 DBC(l,M)=SL(LMN): DBC(2,M)=SA(LMN): DBC(5,M)=SCtLMN) 3662 DBC(6,~)=(100*(5X(LMN)-SXILST-NST)))\LHT :DBC13,M)=ASTRT~MN) :DBC(4,M)=i~END(LMN) 3663 DBC(7,M)=(100*(SY(LMN)-LINY))\LHT : DBC(9,M)=( 50~(32*Y(SNO(LMN)-1)\AY~BY-LINY))\LHT: IF LMN ~1 THEN DBC(8,M)=( 50*(32*Y(2)\AYfBY-LlNY))\LE~T ELSE DBC(~,M)=
( S0*(32*Y(SNO(LMN-1)+2)\AY+BY-LINY))\LHT
3664 IF YX < SYX(LMN) THEN YX=SYX(LMN) 3665 IF YN > SYN~LMN) THEN YN=SYNILMN) 3666 IF XX < SXXILMN) T~EN XX=SXX(LMN) 3667 IF XN > SXN(LMN) THEN XN=SXN(LMN) 3668 IF DBUG > O THEN LPRINT USING r #n;MCHR,DBC11,M),DBC~2,M),DBC(3,M),DBC(4,M),DBC(5,M),DBC(6,M),DBC(7,M),DBC(8,M),DBC(9,M) 3669 IF DBUG < O THEN LOCATE 10+M,27: PRINT USING " #";MCHR,DBC(1,M),DBC(2,M),DBC~3,M),DBC(4,M),DBC(5,M),DBC(6,M),DBC(7,M),DBC(8,M),DBC~9,M) 3670 NEXT M :GOSUB 3700 3671 NPOS=(Z~(XX~XN)\16-IMARGNI\2 3672 REM PRINT ~MCHR,NPOS,CHAR,ED" ,MCHR,NPOS,CS$,ED :INPUT IJK
3673 IF ED = 1 THEN NPOS=0: AS$(MCHR~SCS$
3674 IF NPOS > ~ THEN IF NROS < 40 THEN ~S$(NPoS)=CS$

3676 IF ED <~ 1 THEN LOCATE (LINY-LHT+1)\8,1XX~XN)\16+1 :PRINT CS$

:i r, ~i -4~-., ~32~481 3680 SXX(MCHR)=XX : SXN(MCHR)=XN
3682 SYX(MCHR)=YX : SYN(MCHR)=YN
3688 MCHR=MCHR+1: NST=1: XX1=XX: XX=-1: XN=1000: YX1=YX: YX=-1: YN=1000 3710 R1=16000 :M.~=0 :IF NDBT=0 THEN GOTO 3900 3715 FOR M=1 TO NDBT
3720 IF DN(M) <> NST THEN GOTO 3790 :REM CHECK NUMBER OF STROKES
3725 M2E=9 :IF LINY = 0 THEN M2E=6 .
3730 R=0 : FOR M1 =1 TO NST
3735 FOR M2=1 TO M2E
3738 DR=ABS(DIM2,M3+M1)-DBC(M2,M1~) 3740 IF M2 < 2 THEN GOTO 3744 ELSE IF M2 > 4 THEN GOTO 3744 3741 IF DR ~ 128 THEN DR=ABS(DR-256): GOTO 3741 :REM USE 64 FOR DIRECTION INDEPENDENCE
3742 IF ABS(D~5,M3+M1)~ > 20 THEN DR=20*DR\(ABS(D(5,M3+M1))) 3744 IF DR > 300 GOTO 3790 3748 R=R+DR
3749 IF R > R1 GOTO 3790 3750 NEXT M2 : NEXT M1 3780 MS1=M : R1=R
3790 M3=M3+ DNlM) :NEXT M
- 3800 REM IDENTIFY CHARACTER ~ 4 3803 C5$=CHR$( DC(MS1)) :~:
3804 REM ~:~
: 3805 IF DBUG <~ 0 THEN LOCATE 19,1 :PRINT R1,MS1,CS$

~- 3810 IF R1\NST > ACPT GOTO 3900 :REM CHARACTER NOT FOUND :~

:~ 3900 REM LEARN NEW CHARACTER ~.
: 3902 IF LERN = 0 THEN CS$=CHR$(2): RETURN
:~ 3904 IF KYBD=0 THEN LOCATE 23,1 :I~PUT ~CHARACTER NOT UNDERSTOOD, PLEASE ~YPE IT
IN: ",CS$
3906 IF KYBD = 0 THEN LOCATE 23,1 :PRINT "
3910 IF KYBD=1 THEN GOSUB 11400 3912 IF KYBD =1 THEN GOSUB 9600 3914 IF KYBD =1 THEN GOSUB 11600 : CS$=CHR$(MSEL) 3915 IF CS$=" " THEN GOTO 3960 : 3917 IF ED=1 THEN RETURN
3920 IF NDBT = 300 T-HEN PRINT "Too Many Symbols": STOP
3926 NDBT=NDBT11 : DN(NDBT)=NST : DC(NDBT)=ASC(CS$) 3930 IF M3INST > 800 THEN PRINT "Too Many Strokes" :STOP
3936 FOR M1=1 TO NST : FOR M2=1 TO 9 3940 D(M2,M1~M3)=DBC(M2,M1) : NEXT M2 : NEXT M1 3960 CS$

, 4000 REM CONCATENATE STROKES
4010 FOR L~2 TO NSTRK
4014 IF X(SNO(L-1)) < 0 THEN GOTO ~090 4016 I~ SL(L-1) < 4 THEN GOTO 4100 4020 ALNO=lABS~ABS(X(SNO(L)))-ABS~X(SNOtL-1))~)~ABStY(SNOlL))-Y(SNO5L-1)))) 402l REM LOCA~E 1,1: PRINT ~L,ALNON,L,ALNO
4022 IF ALNO > 100 THEN GOTO 4090 : REM TOD F~R A~AY
4024 ALNO= 8*ALNO\(SNOlL)-SNO(L-1)) 4026 DD =ABS(ABS(X(SNOlL~1)))-A~S(X~SNO(L-1)+2)))1~BS(YlSNO(L-1))-YlSNO(L-1)+2)): 4027 REM P~INT ~L,DD,ALNO~,L,DD,ALNO
4028 IF DD ~ ALNO T~EN GOTO 4090 : REM TOO FAR AWAY
4030 IR1=80*5C~L)\SL(L) : IR2=80*SClL-1)\5LlL-1) ~031 REM PRINT "L,IR1,IR2"~L,IR1,IR2 :: -49-.

13~5~1 4032 IF ABS(IR1) > 350 THEN GOTO 4040 :REM SMALL WIGGLE
4034 IF ABS(IRl) < 80 THEN GOTO 4038 :REM STRAIGHT LINE
4036 IF ABS(IRl-IR2) > ABS(IR1~IR2)\3 THEN GOTO 4090 ELSE GOTO 4050 : REM TOO DIFFERENT CURVATURE
4038 IF ABS(IR2) > 80 THEN GOTO 4036 ELSE IF IRl*IR2 < - 2000 THEN GOTO 4090 :REM
TOO DIFFERENT CURVATURE

4040 IF ABS(IR2) < 350 THEN GOTO 4036 ELSE IF IR1 *IR2 < O THEN GOTO 4090 4050 ASTND=ABS( ASTRT~L)-AEND( L-1)) 4052 I F ASTND > 128 THEN ASTND=ABS(ASTND- 2 56): GOTO 4052 4054 IF ASTND > 64 THEN GOTO 4090 ELSE IF ASTND > DD* (ABSlIRt)+ABS( IR2))\40 THEN

4101 REM PRINT nCOMBININGn L L-1 4110 L1=L-1 :SLL=SL(L1)1SL(L) 4115 IF SLL = 0 THEN LOCATE 23 1 :PRINT ~TWO STROKES WITH NO LENGTH" : STOP
4120 IF SXXtLJ ~ SXX~L1) THEN SXX(Ll )=SXX(L) 4122 IF SXN(L) < SXN(L1) THEN SXN(L1)=SXN(L) 4124 IF SYXIL) > SYX(Ll) THEN SYX~L1)=SYX(L) 4126 IF SYN(L) < SYN(L1) THEN SYN(Ll)=SYN~L) 4130 SX(Ll)=(SL(Ll )*SX(L1 )+SL(L)*SX(L))/SLL
41~3 SY(L1)=(SL(L1)*SY(Ll)+SL(L)*SY(L))/SLL
4137 SA(L1)=(SL(L1~*SA(Ll)+SL(L)*SA(L)~/SLL
4140 SL(L1)=SLL +DD
4150 SC(L1 )=SC(L1)+SC(L)+((SC(L1)+SC(L))*DD)\SLL
4160 SNO(L1)=SNO(L) :AEND(L1)=AEND(L) :
4170 NSTRK=NSTRK-1 : IF NSTRK ~ L THEN RETURN
4180 FOR LL=L TO NSTRK
41B5 L1=LL~1 :SXX(LL)=SXX(L1) :SXN(LL)=SXN(L1) :SYX(LL)=SYX~Ll) :SYN~LL)=SYN~Ll)41&7 SX(LL)=SX(Ll) :SY(LL)=SY(Ll) :SA(LL)=SA(L1) :SC(LL)=SC(L1) :SNO(LL)=SNO(L1)4189 SL(LL)zSL(L1i: ASTRT(LL)=ASTRT(Ll): AEND(LLj=AEND(L1) 4195 ~OTO 4010 4210 M2=0 4220 FOR M=2 TO NP STEP 2 :M1=M-l 4230 IF X(M1) > 0 GOTO 4240 4235 M?=M2~1 :X(M2)=X(M1) :Y(M2)=Y(M1) :GOTO 4280 4240 IF X(M) > O GOTO 4250 4245 M2=M2+1 :X(M2)=X(M) :Y(M2)=Y(M) :GOTO 4280 4250 IF ABS(X(M)-X(M1)) > 30 THEN GOTO 4280 4260 IF A8S(Y(M)-Y(M1)) > 30 THEN GOTO 4280 4270 M2=M2~1 :X(M2)=(X(M)+X(M1))\2 :Y(M2)=(Y(M)~Y(M1))\2 4283 X(M2)-X(NP) 4285 NPaM2 434 2 XCH 0 : IF NSTRK < 2 THEN RETURN
4345 FOR L=2 TO NSTRK
4350 IF SXNlLI > SXNtL-1) THEN GOTO 4~80 4355 XCH=1 :L1=L-1 4360 ST=SXXlL1) :SXX(L1)=SXX(L) :SXX(L)=ST
4361 ST=SXN(L1) :SXN(L1 )=S~(L) :SXN(L)=ST
4362 ST=SYN(L1) :SYN(L1)=SYN(L) :SYN(L)=ST
4363 ST=SYX(L1) :SYX(L1)=SYX~L) :SYX(L)=ST
4364 ST=SX(L1) :SX(L1)=SX(L) :SX(L)=ST
4365 ST-SY(L1) :SY(L1)=SY(L) :SYlL)=ST
4366 ST=SA(L1~ :SA(L1)=SA~L) :SAl~)=ST

( -50~
' .

132~81 4367 ST=SC(Ll) SC(L1)=SC(L) SC(L)=ST
43O8 ST=SL(L1) SL(L1)=SL~L) :SL(L)=ST
4369 ST=SNO(Ll) :SNO(L1)=SNO(L) :SNO(L)=ST

4390 IF XCH = 0 THEN RETURN ELSE XCH=0 :GOTO 4345 6105 LERN=1 : J=3: JJ=J : FOR I=1 TO 40 :AS$(I)=" " : NEXT I
6110 LINY=8* (JJ+3)-1 6120 LINE (0,LINY-LHT-8)-( 639 ,I.INY+LHT\2),0 ,BF
6130 LINE (8*IMARGN-1,LINY)-( 639 ,LINY-LHT), l,B
6140 LINE ( 607,LINY)-(639 ,LINY-LHT),1,BF
6150 IF SWTPN = -1 THEN GOSUB 7100 ELSE GOSUB 8600 :REM TOUCH TECH SCREEN IN ASCII @ 9600 6151 IF SWTPN = 1 THEN &OSUB 7300 6155 IF NP < 8 THEN GOTO 6190 6180 LOCATE 18,IMARGN FOR I=1 TO 40: PRINT AS$11);: NEXT I

6190 FOR I=1 TO 4 ~-~
61 92 IF AS$ ( I ) = n@~ THEN RETURN

6195 GOTO 6105 :

6201 XX=SXX(l ): XN=SXN(1 ): YX=SYX(1 ): YN=SYN(1) 6202 XP=(XN+XX)~2: YP=(YNIYX)/2 :REM AVE CHARACTER POSITION
6203 I=INTlXP/8) 11: J=INT(YP/8)+1 :ISAV=I: JSAV=J: REM CONVERT X,Y Tt~) I,J -~
6204 ML=LL(J): M1=MLII-IMARGN REM CALC A ARRAY IMDEX OF I.ETTER AT I,J ~:
6205 IF A$(MLj=" " THEN Ml=Ml+l 6206 IF A$(ML)=CR$ THEN Ml=Ml+1 ;
6:207 MSAV=Ml 6210:JJ=JSAV : FO~ I=1 TO 40 :AS$(I)=" " :NEXT I :-6215 LINY=8~*1JJ+3)-1 ~
62~20 LINE (0, LINY-LHT-8)-(639,LINY+LHT\2),0, BF
6230 LINE (8*IMARGN- 1,LINY)-(639,LINY-LHT),1,B
6240 LINE (607,LINY)-(639,LINY-LHT),1 ,BF
6250 IF SWTPN = -1 THEN GOSUB 7100 ELSE 9OSUB 8600 :REM TOUCH TECH SCREEN IN ASCII @ 9600 6251 IF SWTPN = 1 THEN GOSUB 7 300 6255 IF NP < 8 THEN GOTO 6270 6258 IF DBUG <> 0 THEN LOCATE 22,IMARGN: FOR I_l TO 40: PRINT AS$~ NEXT I

6270 JB=0: Jz1 6271 REM LOCATE 16,1 FOR I=1 TO 40: PRINT AS$lI);: NEXT I
6272 IE=2 :~OR I-40 TO 2 STEP -1 : IF AS$(I) ~> n n THEN IE'=I+1 : GOTO 6274 6274 FOR I=2 TO IE
6275 IF AS$~I) <> " " THEN GOTO 6280 6276 JB=JB+1 6278 IF J~ < 3 THEN GOTO 6288 6280 J=J+1: JB=0 6282 AS$1J)aAS$lI) 6289 REM LOCATE 17, 1: FOR I=l TO 40: PRINT AS$1I);: NEXT I
6290 AS$~J+l)=n "
6295 IF J < 2 THEN IF AS$tl) =l- n THEN LOCATE 18,1 : PRINT ~'NO l,ETTERS, TRY ~GAI
N" :GOTO 6210 6300 MD=J+l : M3=MSAV I=ISAV : J=JSAV
6 310 REM LOCATE 20,1: F~R I=1 TO 40: PRINT AS$1IJ;: NEXT I

6510 XX=SXX(l): XN=SXNll): YX-SYXI1): YN=SYN(1) 6520 XP=(XN+XX)/2: YP=(YN~YX)/2 :REM AVE CH~RACTER POSITION
6530 I=INT(XP/8)+1: J=INT(YP/8)+1:REM CONVERT X,Y TO I,J
6540 ML=LL(J): Ml=ML+I-IMARGN :REM CALC A ARPAY INDEX OF LETTER AT I,~
6550 IF A$(ML)=" " THEN M1=M1+1 6560 IF A$(ML)=CR$ THEN Ml=M1+1 6570 M2=M1 6710 XX=SXX11): XN=SXNll): YX=SYXll): YN=SYNIl) 6720 XP=lXN~XX)/2: YP=lYN~YX)/2 :REM AVE CHARACTER POSITION
6730 I=INTlXP/8)+1: J=INTlYP/8)+1:REM CONVERT X,Y TO I,J
6740 ML=LL~J): Ml=ML+I-IMARGN :REM CALC A A~RAY INDEX OF LETTER AT I,J
6750 IF A$~ML)-" " THEN M1=Ml+1 6760 IF A$~ML)=CR$ THEN Ml=Ml+l 6770 A$1Ml)=AS$(1) :LOCATE J,I :PRINT AS$(1) 6910 XX=SXX(l): XN=SXN(1): YX=SYXll): YN=SYNll) 6920 XP=lXN+XX)/2: YP=lYN~YX)/2 :REM AVE CHARACTER POSITION : :
6930 I=INTlXP/8)+1: J=INTlYP/8)+1:REM CONVERT X,Y TO I,J
:6940 ML=LLlJ): Ml=ML~I-IMARGN :REM CALC A ARRAY INDEX OF LETTER AT I,J
6950 IF A$1ML)=" " THEN Ml=M1+1 6960 IF A$1ML)=CR~ THEN M1=Ml~l 6970 AS$12)=AS$11) 6980 M3=Ml :MD=l 7010 OPEN`"I",#l,"POINTS.DAT"
~:~ 7020 INPUT #l,AX,BX,AY,BY

7110 INPUT #l,NP
7120 FOR N=1 TO NP
7130 INPUT #l,X(N),Y(N) 7133 IF IFAVE = 1 THEN GOSUB 4200 7134 FOR N=l TO NP
7135 IF X(N) ~ 0 THEN I=32*X(N)/AX+BX ELSE I=-32*XlN)/AX+BX
j 7136 J=32*Y(N~/~Y~BY
7137 PSETlI,J) 7148 IF DBUG > 5 THEN FOR N=l TO NP: LPRINT N,X(N),Y(N):NEXT N
. 7149 IF DBUG <> 0 THEN LOCATE 20,2 :PRINT ~NP=n,NP
j 7150 RETURN

7210 OPEN "O",#l,"POINTS.DAT"
7220 PRINT #1,AX,BX,AY,BY
, 7230 RETURN
¦ 7300 REM STORE POINTS
7310 PRINT #l,NP
7320 FOR N=l TO NP
7330 PRINT #1, USING " ~#"; X(N),YlN) i 8600 REM TT ACQUIRE POINTS IN ASCII @ 9600 WITH INSERT
8603 M=20 ~ 8605 IF LOCl2) > O THEN IPUT$=INPVT$(1,2) : GOTO 8605 :' 8606 PRINT ~2,~G" :N=0 8610 IF LOCl2) ~ 40 THEN GOTO 8610 i~ :

.~

1 3 2 ~ 4 8 1 8620 NU=0: INPUT #2,XP,YP :INPUT #2,XP,YP :INPUT #2,XPA,YPA :INPUT #2,XPO,YPO
8630 N=N+1: XPA=(XPA+XPO)\2: YPA=lYPA+YPO)\2: XPO=XPA: YPO=YPA: X(N)=XPA: Y(N)=YPA
86 3 5 I F 32~XPA\AX+BX > 607 THEN GOTO 8695 8640 INPUT #2,XP,YP
865 3 XPA= ( XP+ 3 *XPA ) \ 4 : YPA=(YP+ 3 *YPA ) \ 4 8657 IF ABS(XPA-XPO)~ABS( YPA-YP 0) < 3 THEN GOTO û 672 8660 I=32*XPA\AX~BX:J=32*YPA\AY+BY:PSET(I,J~
8665 IF I > 607 THEN GOTO 8695 8670 N=N+1 : X(N)=XPA :Y(N)=YPA: XPO=XPA: YPO=YPA
8672 IF LOC(2) > 9 T}IEN GOTO 8640 8675 MM=0 8680 MM=MM+1: IF LOC( 2) > 9 THEN GOTO 8640 ELSE IF MM ~ M THEN GOTO 8680 8685 X(N)=--X(N): IF X(N) = 0 THEN X(N)=--1 8690 IF LOC~ 2) > 39 THEN GOTO 8620 ELSE NU=NU~1 : IF NU < 25000 THEN GOTO 8690 8695 PRINT #2, "S": NP=N
8696 IF DEBUG <> O THEN LOCATE 20,2 :PRINT "NP=n,NP
8697 IF IFAVE = 2 THEN GOSUB 4200 M~:
8698 IF DEBUG < > O THEN LOCATE 20,12 : PRINT NP
8699 RETURN .:~ :
9600 REM TT ACQUIRE POINTS IN ASCII @ 9600 WITH MENU
9603 M=20 9605 IF LOC~2) > O THEN IPUT$=INPUT$(1 ,2) : GOTO 9605 9606 PRINT #2, "G"
9610 II=0 :JJ=0 :N=0 9640 INPUT #2,XP,YP
9660 II=32*XP\AX~BX+II: JJ=32*YP\AY+BY+JJ: N=N+1 9670 IF N < 10 THEN GOTO 9674 9672 I=II\10: J=JJ\10: N=O : II=0: JJ=0 9673 LINE (I+1,J+l )--(I--1,J--l ),1,B
9674 IF LOC~ 2) > 9 GOTO 9640 9675 MM=0 9680 MM=MM+1: IF LOC (2) > 9 THEN GOTO 9640 ELSE IF MM < M THEN GOTO 9680 9690 IF LOC(2) ~ 9 THEN GOTO 9610 ELSE NU=NU+1 :IF NU < 1500 THEN GOTO 9690 9695 PRINT #2, "S"

19700 REM SET UP TOUCH SCREEN FOR ASCII @ 9600 10710 OPEN n I " ~ # 2 ~ "CAL . DAT"
10720 INPUT #2,AX,BX,AY,BY
10730 CLOSE #2 10740 OPEN "COM1 :9600,N,8,1,CS0,DS0" AS #2 10750 PRINT #2, "S"

11100 REM input selection menus 11101 REM mnum= ~o. of items 11102 REM mtitl$-titles 11103 REM miO,mie,mjO,mje=start ~ end points ~or boxes 11105 IF KYBD=1 GOTC) 11400 11110 LINElMIO,MJO)-IMIE,MJE),O,BF :LINEtMIO,MJO)--lMIE,MJE),t,B
11115 XX=MIO : MRATO=(MIE-MIO)\MNUM
11120 FOR K=1 TO MNUM : LINE IXX,MJO)-(XX,MJE) 11130 MJA=IMJO+MJE+8)\16+1 : LOCATE MJA,IXX+20)\3 : PRINT MTITL$(K) 11140 XX=XX+MRATO :NEXT X

11310 IF KYBD=1 GOTO 11600 11320 XX=O : FOR K=1 TO MNUM : XX=XX+MRATO : IF I < XX THEN GOTO 11340 11340 MSEL=R

11405 JMENU=163 : .
^ . ~ 132~481 11410 LINEtl,160)-(639,199),0,BF
11440 FOR I= 1 TO 26 :LOCATE 22,2*I : PRINT CHR$(I+64), : NEXT I
11450 FOR l= 1 TO 26 :LOCATE 24,2*I : PRINT CHR$(I~96), : NEXT I
11460 FOR I= 1 TO 10 :LOCATE 22,2*I+52 : PRINT CHR$(I+47), : NEXT I
11470 LOCATE 22,74 : PRINT ~. ~ ? ~, 11480 LOCATE 24,54 : PRINT "\ / * + _ ( ) , ; : n ;C~R~( ~4 1; n $ &1l;
11482 FOR J=163 TO 195 STEP 16 : LINE~3,J)-~629,J) :NEXT J
11484 FOR I= 3 TO 635 STEP 16 : LINE(I,163)-~I,195) :MEXT I
11490 LOCATE 1 ,1 :RETURN
11600 REM keyboard select from menu 11620 MSEL=(I\8+1)\2 11640 IF J > 179 THEN GOTO 11700 11650 IF MSEL < 27 THEN MSEL=MSEL+64 : RETUR~ .
11660 IF MSEL < 37 THEN MSEL=MSEL+21 : RETURN ~ .
11670 IF MSEL=37 THEN MSEL=46 : RETURN
11680 IF MSEL=38 THEN MSEL=94 : RETURN ~:~
11690 MSEL=63 : RETURN :
11700 IF MSEL < 27 THEN MSEL=MSEL+96 : RETURN
11710 IF MSEL=27 THEN MSEL=92 : RETURN
11720 IF MSEL=28 THEN MSEL=47 : RETURN
11730 IF MSEL=29 THEN MSEL=42 : RETURN
11740 IF MSEL=30 THEN MSEL=43 : RETURN
11750 IF MSEL=31 THEN MSELC45 : RETURN
11760 IF MSEL=32 THEN MSEL=40 : RETURN
11770 IF MSEL=33 THEN MSEL=41 : RETURN
:11780 IF MSEL=34 THEN MSEL=44 : RETURN
11790 IF MSEL=35 THEN MSEL=59 : RETURN
11800 IF MSEL=36 THEN MSEL=58 : RET.URN
11810 IF MSEL=37 THEN MSEL=34 : RETURN
11820~IF:MSEL=38 THEN MSEL=36 : RETURN
11830 MSEL=38 : RETURN

12000 REM input output 12t00 REM:read in text 12110 OPEN "I", #1 ~ ~ITEXTn :NC=0 12120 IF EOF(1) THEN CLOSE #1 : GOTO 12160 12130 INPUT #1, A1$ :KK=0 12140 FOR K=1 TO LEN(A1$) : KK=KK+1 :A$(NC+KK)=MID$(A1$,K,1) 12143 IF LEN(A$(NC~KK))=0 THEN K~-KK-1 12150 NC=NC+KK:IF NC < 1500 THEN GOTO 12120 12155 PRINT "TOO MUCH TEXTn STOP

12170 II=IMARGN : JJ=JTOP : NC1=1 : REM DISPLAY ALL TEXT
12175 CLOSE #t 12505 IF SWTPN <> 0 THEN CLOSE #1 12510 OPEN ~O",#I,"SYM.DAT"
12520 PRINT #1,NDBT
12530 M2=0 :FOR M=1 TO NDBT
12540 PRINT #1, DN(M) DC(M) 12550 FOR M1=M2+1 TO M2+DNlM) 12560 PRINT #1, D~1,M1) D(2,M1) D(3,Ml) D(4,M1) D(5,M1~ D(6,M1) D(7,Ml) 12570 NEXT M1 :M2=M2+DN(M) : NEXT M
12580 CLOSE #1 12710 OPEN ~In,#1,~SYM.DAT~
12720 INPUT #1,NDBT
12730 M2=0 :FOR M=l TO NDBT
12740 INPUT #l,DN(M),DC(M) 12750 FOR Ml=M2+1 TO M2+ DNIM) ~ 3 2 ~
,. .

12760 INPUT #1,Dl1,M1),D(2,M1),D(3,M1),D(4,M1),D(5,M1),Dl6,M1),D(7,M1) 12770 NEXT M1 :M2=M2+DN(M) : NEXT M
12780 CLOSE #1 30000 FOR I=1 TO NSTRK:PRINT I,SNO(I),SX(I),SYlI~,SL~I),SA(I),SC(I):NEXT I
30010 FOR I=1 TO NP:PRINT I,X(I),Y(I):NEXT I
30020 FOR I=1 TO NSTRK:PRINT USING " #";I,SNO(I),SX(I),SY~I),SL(I),SA~I),SC(I :
):NEXT I :
30030 FOR Ml=l TO NST :FOR M2=1 TO 5 :PRINT M1 ,M2,D(M2,M1),DBC(M2,M1):NEXT M2 :N ~
EXT M1 .

132~81 APPENDIX III

Al - angle of slope between Point M and Ml A2 - previous angle DA1 - change in angle (A1-A2) SEND - flag for end of Stroke ZX - double precision X position summation by arc length weighting ZY - double precision Y position summation by arc length weighting ZA - double precision angle summation by arc length weighting ZDA - double precision change in angle summation ZL - double precision length NSP - number of Points in Stroke, counter NSTRK - number of Strokes XX - maximum X
XN - minimum X
YX - maximum Y
YN - minimum Y
M1 - Pointer to previous Point M2 - (1) minimum number of Points for which to adjust for 2~ angle M3 - (2) minimum number of Points for which to calculate change in change in angle NLONG - counter (not used) M - Pointer to Point being considered NP - number of Points X - array of X coordinate Y - array of Y coordinate DX - change in X
DY - ch~nge in Y
ADX - absolute value of DX
ADY - absolute value of DY
DS - pseudo arc length ADX + ADY
AY - calibration multiplier for vertical (Y) direction, e.g.
AY ' O mean coordinate system true downward ADA running average change in angle DA2 - previous change in angle ASTRT - array for starting angle of Stroke SZL - single precision Stroke length SNO - array of number of the 1st Point for each Stroke BHT5 - height between lines divided by 5 in display coordinates used as a measure SL - array of Stroke lengths sealed to height between lines AEND - array of angles at end of Strokes SC - array of angle changes for eachs troke AZA - average angle through Stroke SX - array of averages centroid X coordinate for each Stroke SY - array of ~verages centroid Y coordinate for each Stroke SA - array of averages angle (slope) coordinate for each Stroke SXX - array of maximum X coordinate for each St~oke SXN - array of minimum X coordinate for each Stroke SYN - array of minimum Y coordinate for each Stroke SYX - array of maximum Y coordinate for each Stroke DBUG - debugging flag for printing INPUT - string of input bytes to be rejected XP, YP - input coordinates XPA - average 2 Points in X direction YP~ ~ average 2 Points in Y direction XPO - initial X average on pan down YPO - initial Y average on pan down I - display pixel corresponding to X coordinate input ` 13~81 .
J - display pixel corresponding to Y coordinate input N - counter of input Points -MM - counter for timing pan up ~-~
NU - counter for timing pan up ~''"''''~', -',' .. ' .

Claims

1. Apparatus for recognizing handwritten symbols, comprising:
a display screen:
hand-held means, coupled to said display screen, for writing a handwritten symbol over at least a portion of a first area of said display screen;
means, coupled to said display screen, for digitizing said handwritten symbol to provide a digitized symbol;
means, coupled to said display screen and said means for digitizing, for displaying an image of the handwritten symbol on said display screen in at least a portion of said first area as it is written:
means, coupled to said display screen, for executing a plurality of different editing functions;
means, coupled to said means for digitizing, for correlating said digitized symbol with at least one of a plurality of predetermined symbols including a plurality of font symbols and a plurality of editing symbols, by comparing characteristics of said digitized symbol with stored characteristics of at least some of said plurality of predetermined symbols, to provide one of said plurality of predetermined symbols as a designated symbol which is correlated with said handwritten symbol;
means, coupled to said display screen for displaying a computer-generated symbol on said display screen when said designated symbol is a font symbol and for executing at least a first of said plurality of editing functions when said designated symbol is a first of said plurality of editing symbols, and for executing at least a second of said editing functions, different from said first editing function, when said designated symbol is a second of said plurality of editing symbols.

2. Apparatus, as claimed in claim 1, wherein at least said means to execute at least a first editing function and said means for correlating said digitized symbol include an electronic processor.

3. A method for recognizing handwritten symbols, comprising:
providing a display screen;
writing a handwritten symbol over at least a portion of a first area of said display screen;
digitizing said handwritten character to provide a digitized symbol;
displaying an image of the handwritten symbol on said display screen in at least a portion of said first area as it is written;
correlating said digitized symbol with at least one of a plurality of predetermined symbols including a plurality of font symbols and a plurality of editing symbols, by comparing characteristics of said digitized symbol with stored characteristics of at least some of said plurality of predetermined symbols, to provide one of said plurality of predetermined symbols as a designated symbol which is correlated with said handwritten symbol;
displaying a computer-generated symbol on said display screen when said designated symbol is a font symbol;
executing at least a first of said plurality of editing functions when said designated symbol is a first of said plurality of editing symbols; and executing at least a second of said plurality of editing functions when said designated symbol is a second of said plurality of editing symbols.
4. Apparatus, as claimed in claim 1, wherein said plurality of font symbols includes at least one chemical equation symbol.
5. Apparatus, as claimed in claim 1, wherein said plurality of font symbols includes at least one music symbol.
6. Apparatus, as claimed in claim 1, wherein said plurality of font symbols includes at least one symbol for graphic manipulation of data.
7. Apparatus, as claimed in claim 1, wherein said symbol for graphic manipulation of data is a symbol for transfer of graphic data to a spreadsheet.

8. Apparatus, as claimed in claim 1, wherein said plurality of font symbols includes at least one equation.

9. Apparatus, as claimed in claim 1, wherein said plurality of font symbols includes at least one of an ideograph.

10. Apparatus according to claim 1, wherein one of said plurality of editing functions is a margin set function and wherein one of said plurality of editing symbols, corresponding to said margin set function, is a vertical line drawn down the side of displayed text where the new margin should appear.

11. Apparatus, as claimed in claim 1, wherein at least one of said editing functions is a function to move text and wherein one of said plurality of editing symbols, corresponding to said text move function includes brackets placed around a displayed group of symbols, and a caret.

12. Apparatus, as claimed in claim 1, wherein said step of correlating is performed by a computer and further comprising using said computer to learn the editing symbols used by a particular writer.

13. Apparatus, as claimed in claim 1, wherein said computer is further configured to provide a database of stroke sequences corresponding to characters and to effectively reorder the database to minimize time required to recognize the most frequently identified characters.