CA1157567A - Text recorder with automatic word ending - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A text recorder includes a text display device to record text in intelligible form on a typewritten page or line or page-like display in response to character and function identifying signals. A keyboard is included having a plurality of alphabetic, numeric, symbol and function keys for actuation by an operator to produce a keyboard signal unique to the actuated key. A decoder is responsive to keyboard signals from the keyboard to produce character and function identifying signals, such decoder including a word completion facility for producing one of at least two groups of one or more character identifying signals in response to actuation of a selected key on the keyboard, each group of character identifying signals representing a different word ending. The word completion facility includes a selection feature for selecting among the group dependent upon the identity of one or more keys actuated prior to actuation of the selected key.

Description

~ 1~7~7 T~XT RECQRVER WITII AVTO~IATLC WORD ~NDING

Field o~ the Invention The present invention deals with improvements in te~t recorders, i.e., typewriter or typewriter-like devices which may produce intelligible -text of printed form or a text display by the use of a CRT or the like, or both.

BACKGROUND OF THE INVENTION

There have been many suggestions made to improve keyboarding efficiency in typewriter and typewriter-like devices. There have also been suggestions for devices to automatically verify the spelling of text input through a keyboard. A particular disadvanta~e of most such devices is the relatively vast amount of storage required, and several recent suggestions, such as those disclosed in U.S. Patent No. 3,024,761, issued March 13, 1962, to Bruce ~. Bertelsen, entitled "Vacuum Evaporation Apparatus" and U.S. Patent No.
3,005,254, issued October 24, 1961, to Donald E. Thomas, entitled "Brazed Zirconium Base ~lloy Structures", evidence an effort to reduce the required amount of storage.
The addition to the typewriter (which is itself about 100 years old), of the intelligence afforded by programmed digital computers, and even more recently by the microprocessor, allows a vast improvement in the intelligence of the device without significantly increasing the space it occupies since the microprocessor itself and its related storage devices can easily be enclosed in otherwise unused spaces within a typewriter casing.
Electronic typewriters, i.e., typewriters including digital processors, on the market today generally are comprised of three basic components. A first component is the LE9-78~037 ^~

1 1~7567 keyboard itself which generally has an appearanc~ ~imi-lar to other conventional typewriters in that thQ l~yout of the alphanumeric keys is standard, although it may have a few additional function implementing keys. In contrast to the earlier mechanical or electro-mechanical typewriters, the function of the keyboard in the modern electronic type-writer is merely to generate a unia~ue signal in dependence upon a particular key actuated by an operator. This signal sometimes called the keycode, is then presented to the elec-tronics, which is the second major component in the type-writer. The function of the electronics is to interpret the keycode in order to generate character or function identify-ing signals which are fed to the third component, i.e.~ the display mechanism for the generation of alphabetic symbols, numerical symbols, punctuation marks, other graphic symbols, and the functions necessary to relate these symbols. These various symbols must be related in a format which is easily understood by a reader and this requires such functions as spacing between different symbols, spacing between words, spacing between lines, and locating symbols in an ordered sequence as determined by the operator's actuation of the various keys on the keyboard. The particular form which the character and function identifying signals take de-pends in large part on the form of the display or output mechanism. For example, in those typewriters which inclucle a print ball, the character identifying signals must be such as to cause the ball to rotate and tilt to the proper orientation to locate the desired character with respect to the printed page so that when the ball is impacted, the desired character symbol will be produced~ On the other hand, in those typewriters employing an ink jet printer, the character and function identif~ing signals may take on different characteristics, and the same character and function identifying signals for use with the CRT or the like display possess still other requirements. Inasmuch as the present invention can be employed with all of these, and other equivalent output devices, the specific form of the ~ ~7S~

character and function iden~ifying signals will no~ be detailed here as they are well known to those skllled in the art.
In large part, the electronic typewriter mimics the function of the electromechanical or mechanical typewriter.
More particularly, in the mechanical typewriter, the oper-ator's actuation of a specific key produced the combination of mechanical movements which xesulted in a t ~e ~ar carry-ing an image of the character associated with the actuated key impacting a typeribbon into a page to produce an im~
age of that character and to also allow the paper carrying carriage or a movable print carrier to be displaced so that - a next character is printed adjacent the previously printed character. In other words, this mechanical typewriter trans-lated the operator's actuation of a specific key to a speci-fic set of mechanical movements to produce the desired image.
Similarly, the electronic typewriter translates the key code genexated by the operator's actuation of the key in the keyboard to those signals necessary to produce the desired image frcm the particular display device being driven.
However, with the intelligence added to the type-writer by the digital processor, additional functions can be implemented; one important function is the buffering be-tween input and output provided by a storage device contained in the electronics, Thus, most electronic typewriters in-clude a buffer into which the keycode is stored, and se-quential key actuation result in the storage of sequential keycodes identifying the keys and the sequence in which they are actuated. The output device is then driven sequentially from the keycodes xead from storage and translated through the medium of a storage table correlating keycodes and character or function identifying signals.
Hereinafter when referring to electronic typewriters we use the term as equivalent to a text recorder in that "typewriter" no longer carries the implication of a machine necessarily requiring "type" to produce a text record.
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3 1~7557 By text recor~er we mean any device which produces a record (whether or not permanen-t) of a series of text characters and symbols interrelated to convey meaningful information to a human reader.
An earlier disclosure shows how, under certain circumstances, the actuation of a single key can be decoded into a string of character signals, so that actuation of a single key can produce a multi-character output. This earlier disclosure further shows how, under certain circumstances, the particular multi-character output produced by the actuation of a specific key can be vari.ed.
One feature of the earlier disclosure no~ed above is that of producing a first multi-character string upon the Eirst actuation of a specific key, ana producing a second multi-character string on a second sequential actuation of the identical key. Another feature of the earlier disclosure noted above is that of producing a first or second single or multi-character string upon the actuation of a specific key in dependence upon the identity of a key actuated prior to the specific key. This feature allowed the multi-character text recorder to output either a suffix or a word; the suffix was produced if the previously entered key was a character and the word was produced if the previously entered key was a function such as a space or carriage return.
The present invention is arranged to solve a related but slightly different problem and to assist in both improving keyboard efficiency by generating a multi-character signal string in response to actuation of a single key, and at the same time, insuring the correctness of the spelling of the words so typed. In particular, many word endings sound the same but are spelled differently.
For example, the word endings having the sound "ceed" can be spelled "sede", "cede", or "ceed". Thus, it is an object of the present invention to provide a typewriter or text recorder for producing a multi-character signal string identifying 1 ~575B7 one of plural character strings representing word endings which sound the same. The selection is made in dependence upon previously entered characters forming the remainder of the word for which the word ending is desired. Thus, for ex-ample, a typewriter or text recorder in accordance wi-th the present invention may have a plurality of word ending keys, each associated with different1y spelled word endings, all sounding the same, each key, when actuated, produces the appropriate word ending associated with the previously entered characters. While such word ending wxiting keys can be keys in addition to those found in the standard keyboard, they can also be incorporated within the standard keyboard by being associated with keys which are infrequently used during text typin~. In those cases where the ~ord end-lS ing writing key functions are lncluded in the conventionalkeyboard, a mode key can be provided to the operator to only allow automatic word ending writing when the text recorder is in a word ending writing mode, or to prevent automatic word ending writing when the text recorder is not in a word ending writing mode~ On the other hand, such a decision can be removed from the hands of the operator by incorporating within the logic of the text recorder the decision as to whether or not automatic word ending writing is appropriate which decision can also be made dependent upon previously ~5 entered keys.
Furthermore, while signals representing different word endings in each word ending group can be generated from a different key, a relatively large dictionary o~ word endings, some of which sound the same and others of which do not, can be produced by the actuation of a single word ending writing key, the specific word ending produced on actuation of the key being dependent upon the previously entered keysO
Summary of the Invention Thus, in accordance with the invention, an automatic word ending typewriter includes a text display device, i.e., impact print2r, ink jet printer, CRT display or the like, which displays intelligible text in response to character and ~ ~7567 1 fun~tion identifying signals, a keyboard for actuation by an operator lncluding a plurality of keys, each of which produces a unique key code when actuated and a decoder responsi~e to th~ keycode si~nals from the key~oard for producing one of at leas-t two groups of one or more character iden-tifying signals in response to actuation of a selected key on the keyboard, each group of character identifying signals representing a different word ending, wherein said word ending means includes means for selecting among said groups dependent upon one or more key actuations prior to actu~tion of the selected key.
Different embodiments of the invention are presented, each of which, however, employ a sequential logic processor as the decoding means and in which the sequential logic processor include the word ending means.
In one embodiment of the in~ention, which employs decision tree processing, a decision tree is implemented beginning with the identi-ty of the key entered prior to actuation of the elected key~ Each branch in the tree represents a previously entered key. Each node in the decision tree is represented by a table which has an entry for each branch connected to the node. Any node which is not connected to another node (i.e., no branch) identifies the desired word ending and therefore, the associated entry in the table includes identification of the desired character string forming the word ending. In the event that the node is connected to another node, instead of containing a representation of the desired character string, it contains a representation which, when summed with a representation of the next prior character, points to an entry in a further table. In effect, the decision tree processor begins with initiation of automatic word ending, retrieves from a memory an immediately prior entered character. This character keyboard, or keycode related quantity directs the processor to a table entry which itself points to: (a) a selected word ending; (b) a further table or ~c) a default entry. If -the entry directs the processor to a further J, r~

7 ~ ~7 table, a further prior entered character is extra~ted which directs the processor to a specific entry in the further table. This entry also has the same ~hree possibilities.
Processing is carried out by sequentially retrieving prior entered characters until result (a~ or (c) is achieved.
The processor determines the appropriate word ending by traveling through the decision tree from branch-to-~ranch until the desired word ending is located.
In another embodiment of the invention, a sum is formed of quantities unique to each alphabetic character~
and cleared on selected functions or characters such as space function, numerical character or the like. When the selected key is actuated, the sum is used as a pointer to the desired word ending string.
In a third embodiment three word ending designators are available to allow ready selection among a relatively large group of word endings with minimum processing time and storage requirements.
The first designa-tor is the identity of the key entered just prior to automatic word ending initiation. This is determined by reading from a storage buffer into which key-codes are written in the sequence that keys are actuated by the operator. In some cases the identity of the charac-ter will uniquely identify the appropriate word ending or immediately signal a default conditionO In either event, processing is texminated. If the identity of the immediately preceding character is inadequate then the second designator is employed. A character preceding table (CPT~ stores, for each potential character information representing an appro priate word ending, a default condition or a pointer to a further table if this single designator cannot uniquely determine an appropriate word ending~
As each character in a word is keyed in by the operator a quantity, uniquely related to each actuated key~ is added to a prior sum in an accumulator (termed the alpha sequence ID register~. This sum, at the time automatic word ending iS initiated can be used to select an appropriate word LE9-78-~37 ... . ..

ending.
For the few cases in which the two designators are in-adequate a third data item can be used to resolve the remain-ing conflicts. For example, ~his third data item can com-prise the first character in the word corresponding to oneof two ~or more) otherwise apparently appropriate word end-ings. This third data item can be compared with the firs~
character keyed in by the operator. A match or lack of match then indicates the correct word ending if there are only two lQ available choices. The presence of three or more choices requires one or more comparisons.
The use of plural designators allows the designators to be chosen to effec~ively select appropriate word endings with minimum storage and processing requirements in accordance with the ensemble of allowable word endings.
In the embodiments of the invention presented herein, the representation of the word ending string pointed to, when the desired word ending has been determined, can alter natively comprise a memory area which stores the necessary

2~ character identifying signals, or on the other hand, a memory area which s~tores only pointers to the memory areas which already store representations of the desired character identifying signals. The latter alternative is disclosed in detail in the above-referenced copending application, in which a start address storage area stores a plurality of pointers, each pointer representing the address of a sequence of pointers~ the sequence of pointers each pointing to repre-sentations of the character identifying signals.
In one form of the invention, the selected key, which generates the keycode calling for automatic word ending, may comprise a key which is used uniquely for this purpos~. The key can be arranged to address all possible word endings which are automatically written, and the selection between the available word endings is determined by the characters associated with the previously actuated keys. On the other hand, a set of keys can be used, each of the keys generating '~:
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1 1~75~7 _ 9 _ a different keycode and each of them actuating automatic word endiny operation. Each o~ these keys i5 associated with a different group of word endlnc3 character strings;
one convenient manner of grouping the word ending charac-ter strings ~or each key is by grouping the word endingstrings that sound alike. A further alternative is to use multi-purpose keys to generate the keycode to actuate automatic word ending. In order to designate the desired effect of the keycode from lQ such a multi-purpose key, a further ke~ can be employed to place the machine in an automatic word ending mode or re-move the machine from an automatic word ending mode~ This mode selection key is arranged to set ox xeset a latch, and when the latch is set and the multi-purpose key is actuated, automatic word ending is performed In this alternative, a single multi-purpose key can be u~ed to address all pos-sible word endings, or groups of word endings can be as50-ciated ~ith different multi-purpose keys Finally, the multi-purpose key can be arranged to initiate automatic woxd ending only if a previously actuated key was a character (or a h~phenl as ~ill be disclosed.
The case in which the word ending appears can be fixed either as upper ox lower case or, preferably, the case is determined by the status of the shift or shi~t lock sig-nals at the time the automatic word ending actuating key isdepressed. More particularly, the conventional shift or shift lock keys on the typewrit~r control tne status of the shift and shift lock latches. When the shift ke~ is de-pressed, the shift latch is setr ~hen the shit key is released, the shift latch is reset. When the shift lock key is depressed, it is mechanically xetained in its depressed - condition, and a latch is set. On the next depression of the shift lock key, it is mechanicall~ ~eleased, and the shift lock latch i$ reset. These latche~ provide shift and shit lock signals which con~entionall~ control the case in which a character is displayed, If eithe~ the shift lock LE~-78-Q37 .. . . ~ . . .. .. . ... . . . .

l 1~7~67 or shift latches are set, the cha~acter is displayed in upper case, if both latches are reset, the charac~er is displayed in lower case. Pre~erably, the status of the shift and shif~ lock latches is retained ~i.e., stored~
at the time the automatic word ending key is actuated, and the display of the various characters in the selected character string are made in a case determined b~ the`
status of the s~ift and shift lock latches at the time the key actuating the automatic word ending operation lQ is actuated.
Finally, the invention also includes the disclosed method of automatic woxd ending in a text recorder of the type having a text display for the displa~ o~
text in intelligible ~ormat, a keyboard with plural alpha, numeric function and symbol graphic keys for pro-ducing a unique keycode on actuation, and decoding means responsive to the key 2a codes for drivlng said text display wherein the method comprises the steps o :
storing a CPT table representing a matrix of appropriate word ending represen tations as a function of a character pre~
ceding a word ending, if said preceding character uniquely identifies an appro-priate word ending, addressing said CPT table with a repre-sentation o~ a character preceding actuation of an automatic word ending initiatin~ key activation to identify an appropriate word endin~, and employing said identi~àcation to select appropriate signals to drive said display to display ~aid identified word endin~, ,. . . . . . . . .

I ~S75~7 Brief Descri~tion o thP ~rawln~s The present invention is now further described in the following portion of the specification to enable those of ordinary skill in the art to practice the invention, when taken in conjunction with the attached drawings in which like reference characters identify identical appara-tus and in which:
Figures 1, 2, 3A and 3B illustrate different arrange-ments of a typewriter keyboard for use with khe present invention;
Figures 4A-4C are block diagrams of three embodi-ments of a text recorder;
Figure 5 shows a decision tree appropriate or the "ceed" sounding word endings;
Figure 6 illustrates table appropriate for the de-cision tree of Figure 5;
Figure 7 illustrates the logic flow for the decision tree processing;
Figures 8 and 9 illustrate the start address tables with the pointers to function control storage;
Figure 10 illustrates the logic flow for processing associated with the alpha sequence register word ending selection;
Figure 11 is a table showing frequency of occurrence of an assembly of eight word endings as a function of the character preceding the word ending;
Figure l2 illustrates the CPT table appropriate for the third embodiment of the invention;
Figures 13A and 13B-D represent alpha table format and the plurality of alpha tables whose use is appro-priate with the third embodiment;
Figures 14A and 14B illustrate the exception table format and an exception table appropriate to the third embodiment;
Figure 15 represents the character sequence table useful for producing a character string once an appropriate ~ ~7~67 start address,representing the desired word ending, has been determined;
Figures 16A-C illustrate the logic flow appropriate to the third embodiment, and Figures 17A and 17B illustrate supplementary logic in connection with use of a multi-purpose key without use of a mode latch.
Detailed Description of Preferred Embo~iments Figure 1 illustrates a typewriter keyboard laid out in accordance with a preferred embodiment of the invention to e~ecute automatic word ending operation~ As shown in Figure 1, the layout of the alpha-numeric keys and function keys for conventional typewriter operation is conventional.
Figure 1 illustrates three variations over such a conven-tional arrangement; firstly, a word ending mode key 38 is illustrated which, when actuated, will change the mode ofthe text recorder from automatic word ending to non-automatic word ending and vice versa. O course, the location of the key 38 in the illustrated keyboard is subject to wide vari-ations. Secondly, the fraction key 35, the key to the right of the "p" character key, will, when actuated in the wordending writing mode, produce the character identifying sig-nals appropriate to the previously executed character keys, such as the multi-chaxacter word endings "cede", "sede"~
"ceed", "tion", "sion", "i~e", "ise", or "yze"~ Finally/
indicator 22 such as a light emitting diode r is available within the operator's viewing area to indicate whether or not the text recorder is in the aut~matic ~ord ending mode.
Indicator 22 may be energized when a latch~ set and r~set on alternat~ actuations of key 38, is set.
In operation, in the automatic word ending mode, that ;s, with the indicator 22 illuminated, assume the opex-ator actuates the keys corresponding to characters "pre" and then actuates key 35. In response to sequential actuation of the keys "pre", the text recorder will display the characters "pre"~ Furthexmore r coded signals representing the actuated keys are stored in a buffer in the order of their actuation. When key 35 is actuated, the t~xt r~corder 7 5 ~7 determines that it is in the auto~atic word endinq mode and therefore, display of either of the fraction charac-ters l/2 or l/4 is inhibited. Rather, the text recorder identifies the previously actuated key (e) and detarmines the appropriats word ending string, or determines that the appropriate word ending string cannot be determined from the identity of the previously entered key and therefore, further processing is initiated which may examine the key tr) entered previous to the previously entered key. This process continues until the appropriate word ending string -~ is identified from one or more previously entered keys or other processing to be disclosed herein. When the identity of the apprspriate word ending is accomplished, the appro~
priate word ending is displayed adjacent to the previously lS entered characters. In the example described, the appro-priate word ending to the characters "pre" is "cede".
The case of the automatically displayed word endi~g characters is also determined by the text recorder in re-sponse to the status of the shift and shift lock latches r which status is controlled by the shift lock key 41 and the shift key 40.
In the event that key 35 i5 actuated when the auto-matic text recorder is not in the automatic word ending mode, then the appropriate fraction character, either 1/2 or 1/4, will be displayed depending upon the status of the shift and shift lock latches, as is conventional in the prior art type-writers. It is also within the scope of the invention to allow the recorder to determine upon actuation of key 35, whether automatic word ending is appropriate. This can be determined from the previously entered key. If it is an alpha character and the automatic word ending i5 appro-priate the word ending is induced. On the oth~r hand, if previous key is a space function or a key other than an appropriate alpha character the logic defaults to the fraction display.
Figure 2 is an alternate arrangement for the key~oard 1 ~75~7 according to the present invention. The keyboard of Figure 2 is identical to the keyboard of Figur~ l with the exception that the raction key 35 i9 no longer associated wi~h the automatic word ending operat~on~ Rather, the numeral keys 28~30 are IlOW associated with ~he au~omatic word ending mode, wherein ~ey 28 is associated with a group of three word ending~, k~y 29 is as~ociated with another group of word endings and key 30 i~ associated with a third group o~ three word endings. Automatic word ending operation is available when the text recorder is in the automatic word anding mode, much as in the example deqcribed in connection with Figure l.
However, when any o~ keys 28 30 is actuated in the automatic word ending mode, only on~ group of three word endings will be examined to determine the appropria~e word ending.
Figures 3A and 3B show two further keyboards in accor-dance with the present invention. ~he keyboard of Figures 3A and 3B diffor from the keyboards of Figures l and 2 in that the word ending mode key 38 has been eliminated. Rather, the keyboard of Figure 3A incorpora~e3 an automatio word ending key ll whiah, when actuated, will initiate the auto-matic wora ending to ~elect among a large group of possible word endings, ~ome of which sound alike, and others o~ which do not. Figure 3B i9 a fuxther alternative in which the word ending key ll o~ Figure 3A has been replaced by I key Zs 12 and a II ~ey 13~ ~ i9 implied in Figure 3B, when I key 12 i5 actua~ed, an appxopriake word ending from the group "ceed", 7'c~de", or "~de" wlll be ~elected and di~played depending upon tha pre~iously entered character or charac-ter~ Similarly, when I~ key 13 is aatuated, the appro-30 priate wo~d e~din~ among ~he possible word andings "ize","i9~1' or ~yze" will be ssleated and di~pla~ed, dep~nding upon the identit~ o one or more previou~ly entered charac-t~xs .
On~ embodimant o ths automatic word ending text 3S record~r o~ the invantion is illus~xated in bloak diagram~ashion in FigurQ 4~. The keyboard 20 shown in Figure 4A

LE9-78-~37 .~. ,, .. . . . . .. . . . . .. .... . . .. . .

1 ~57~

can by of any of the keyboards illus-trated in Figures 1, 2, 3A or 3B. Each of the keys in the keyboard 20 ls associated with a switch; actuation o~ a key, and the corresponding contact closures or other key to signal producin~ means of the keyboard 20 are accepted by the Iceyboard interface 1, and used to generate a multi-bit code (keycode) representative of an actuated key. The d.isplay 21 is driven by the interface 5~, and can comprise a hard copy printer of any of a plurality of conventional such printers, or a C~T
display or the like, also conventional. The digital processor 50, illustrated in Figure 4A, is employed to respond to each of the different key codes provided by the interface 1, and to output the necessary character and function identifying signals to the interface 5~ to appropriately drive the display 21. While a preferred embodiment employs a microprocessor, which is preferable from the size standpoint, those skilled in the art will understand that other digital processors could be used instead.
As shown in Figure 4A, the digital processor 50 is coupled to the keyboard interface 1, and -to the output interface 54 via data, address and con-trol lines. The digital. processor 50 includes a sequential logic processor Imicroprocessor) 52 and a read only storage (ROS) device 53.
Also coupled to the data, address and control lines of the microprocessor 52 is a read/write storage (R/W) device 51.
Preferably, the read only storage 53 embodies, in coded form, a set of predetermined responses for the processor 52 as well as fixed data which will be defined hereinafter.
For example, the fixed da-ta may include da-ta corresponding to the function control storage (translating keycodes to character and function identifying signals), files containing pointer information for pointing to specific locations in the function control storage, etc. The read/write storage 51, on the other hand, may include reserved areas for the storage of the keycode of the keystroke being processed~ as well as keystrokes awaiting processing, and in addition, an area reserved for previous key ,. ~, ,3' 1 ~57~67 entry or entries.
Before describing the operaticn of the inventive auto-matic word ending apparatus, normal operation of an electron ic typewriter o~ the form generally shown in Figure 4A will be discussed.
When a key in the keyboard 20 is depressed, the con-tact closures, in connection wi~h t'i~ k~yboard interface 1, generates a multi-bit code, called a keycode, which is unique to the actuated key. ~h~ microprocessor 52 re-sponds to recognition of the keycode firstly by storingthe keycode in a register which may reside in processor 52 or the R/W storage 51, in an area set aside for the pre-sent keycode. Once the keycode is stored, the processing of the keycode is begun. Typically, the pl-ocessing is li-mited to determining the corresponding character or functionidentifying signals which will b~ output to the interface 54 to drive the display mechanism 21. This tran,slation of the coding function is effected by employing the keycode as an address into a reserved area of the ~f;~ 53 (function control storage), at which tha corre3ponc;Jng c~arac~er or function identi~ying ~ignal~ are s~ored. While normally the procass-ing o~ tha keycode entxy i~ rapid, tha proce~ing of some entri~s m~y require ~igni~icant amount~ of time and thero-fore, the input/output operations may be int~rrupted to 25 ~or~ a ~ubseguenl: k~ycode. By appropr~ at~ u~e o~ pointer~, the microproce~or 52 c~n ~eep track o~ the locatlon of pre~ent keyaode b~lng processed ~o thak sub~e~uent keycode~
can be proc~ed in tha order o~ th~ir receipt. At ~ome time in th~ proce~sing o a key~ode i i~ al~o ~tored in a buf~er in ~/W ~torag~ Sl ln an area res~rved ~or ~he lina (or other length) of text tha~ i9 heing gen~rat~d. Thus, the R/W ~torag~ 51 may r~tain pll~xal k~yaode~, or exampl~, tho~e e~t~Eed bekw~en the ~rst indexincJ o~ the plat~n, to ~t~rt a llne, and ~ secon~ indexing o~ the platen/ to terminate d~play oX a line and to bsgin opsration~ on a~o~h~r li~e. ~hu~, no~ only do~ ~h~ mi~roproG~ox 52 ~esp g~ask o~ th~ k~y~ode~ b~ing proaa~d, but it can ~l~o L~9-78-037 1 ~ 57567 refer to previous keycodes entered in the same line of type or in some other length text stxing.
The read only storage 53 r in addition to containing the various tables which will be described hereinafter contains the instruction~ for keycode and display pro-cessing routines which, in effect, personalize the processor 52 and provide it with the desired charact~ristics. Tho~e psrtions of the processing routines which merely store the kéycode in the RjW storage 51 and increment the pointer to the next available keycode storage location, as well as the output processing functions which select a decoded or ~ranslated character or function signal and provide it to the interface 54 for display puxposes, will not be des-cribed herein inasmuch as those functions are well known to those skilled in the art~ The intermediate functions, ho~ever, namely, those of extractlng the kaycode from the R/W storage 51 and tran~lating that code into a character or function signal or a multi-character signal for auto-matic word ending in accordance with the present invention will be described herein. Before describing that process-~ing, we will now describe the various resarved areas in the read only storage 53 which are used during that processing.
A first reserved area in read only storage 53 cor-responds to the ~unction control storage 6 of the above-referenced applicakion. This reserved area is addressed by a keycode, eithex directly, indirectly or in a relati~e fashion, and ~tored at the corresponding location is the respective character or ~unction signal necessary to drive the display 21. Thus~ for example, at the location cor-responding to a space keycode wQuld be those signals nec-essary to escape the display mechanism print point in the case,of an impact pr.illter or similar function in the case of a,CRT or ink jet p~inter, Likewise, the entries or characters, in addition ~o allo~ing the spacing unction to proceed after pi~inki~lg or display, provide for printing or di~p?~y of the appr~priate ~hara~ts~-~ and the case ~uppa~ or lower) may be determined by a control signal LE9-78-~37 :~ ,y ) .. ..
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... .. ~ ., . ~ .. ... .. ... . . . .

5~7 which accompanies the character iclent.ifyln~ n~l ~r m~y be derived from the function control s~orage area itself.
DECISION TREE EMBODIMFNT
In addition to these areas, a decision tree proce~sor embodiment includes one or more control table for the pos-sible word endings, to implement the decision tree processor.
Before discussing the makeup of those control -tables, refer-ence is made to Figure 5 to illustrate the decision tree for the word endings "ceedi' r "se.de" and "cede".
As shown in Figure 5~ actuation of the automatic word ending operation ~AWO) directs processing to begin at a node N1. At node ~l, seven possible paths (branches) can ~e taken depending upon the previously actuated key; branches are provided for any of the characters R,O,E,X,N,C. If the preceding keycode is none of those, that is, for example, if the automatic word ending is initiated after a space oper-ation, for example, the decision tree can not determine anappropriate word ending since none of the availahle word endings would be appropriate, ana thus, a default location is also available. Thus, from the node Nl, depending upon the previously entered keycode, certain branches of the tree lead directly to an appropriate word ending, i.e., the branches corresponding -to keycodes of O,E,X and N. How~
ever, if the previously entered character corresponds to an R or C, node Nl is connected to nodes N2 and N3l node N2 associated with a previously entered ~, and node 3 associ-ated with a previously entered C.
If the previously entered character was R, then from node N2 two branches are available, either a default branch or a branch correspondin~ to an E entered prior to the R.
This branch leads to node N4. Node N4 has has three bxanches available to it, one a default branch and the others cor-responding to the characters P and T preceding the E, each associated with an appropriate word ending. Thus, for ex-ample, if the three prior characters are TER, then theappropriate word ending is "cede" (corresponding to ~he word intercede) and if the previously entered characters are PER then the appropriate word ending is "sede" (cor-.

1 ~7~6~

l responding to the word supersede~. Similarly, node N3 has three branches available to it, a flrst branch which is a default branch, a second branch corresponding to a previously entered ~ character, and a third branch corresponding to a previously entered U character. Thus, if the previously entered two characters are UC, the appropriate word ending is "ceed" (corresponding to the word succeed3 and if the previously entered characters are AC, then the appropriate word ending is "cede" corresponding to the word "accede".
It should also be understood -that some of the branches on the tree actually correspond to multiple words. That is, for example, the E branch (from node Nl) provides the appropriate word ending (cede) when the previously entered character is an E and this can correspond to any of the words "precede", "recede", "secede" or "antecede".
From the foregoing, it should be appreciated ho~ the decision tree can be built up for any group of similarly sounding word endings, or for any group of word endings which can be distinguished from one another.
Figure 6 illustrates Continue Tables 1 through 4 to implement the decision tree processing of Figure 5. Each o the Continue Tables comprises a reserved area in the read only storage 53, each entry comprising a multi-bit entry including a pair of flags and a pointer. The pointer may point to a further table or to a further reserved area in the read only storage 53 which represents the desired word ending. Referring now to Figure 6 and Tables 1 and 3 therein, (corresponding to Nodes Nl and N3 of the decision tree~ it will be seen that Table 1 includes an entry for each di~ferent branch of the node Nl. The C branch entry includes a flag combination 10, and a pointer to Table 3 (corresponding to node 3~. The R branch includes the same flag combination 10 and a pointer to the R group, i.e , Table 2, corresponding to node N2. The E and N branches of Table 1 include the flag combination 00, and a pointer ~ ~57~7 to a reprasentation of the l'c~d~" word ~n~ln~ Th~ O .~ 1 X
b~anches include similar flags and a pointer to the "ceed"
word ending. Finally, each other entry (only some of which are shown) corresponds to the last branch and contains a default entry indicating that no appropriate word ending is a~ailable.
The C group entry at Table 1 points to a reserved area corresponding to Table 3 (representing node N3) and in the course of processing a particular entry a pointer will be developed to a specific entry in Table 3 depending on the character entered previous to the C. If that character was an ~, then the A entry of Table 3 is pointed to, if the previous character was a U, then the U entry is pointed to, and if the previous character is something lS other than that, one of the default entries is pointea to.
The A entry in Table 3 includes the flag combination 00 and a representation of the word ending "cede". The U entry includes the flag combination 00 and a representaiton of the "ceed" word ending. In a similar fashion, the R entry in Table 1 points to Table 2 (representing node N2). One entry in Table 2 points to Table 4 (representing node N4) which includes entries for characters P, T and a default entry for any other character.
The two flags provide for four di~ferent possibilitiesO
Flag 00 indicates that the decision tree processing is com~
plete, and an appropriate word ending has been identified.
Flag 01 indicates a short word with an identified word end-ing. Flag 10 indicates theprocess is not yet complete and th~ associated pointer is to another Table. Finally, the flag combination 11, indicates a default, i.e., no appropri-ate ~ord ending is available.
In order to enable this processing the processor 52 must be able to distinguish prior key entries and use their identity to address appropriate locations in the Table. To that end~ each different key code is assigned a unique num-ber and a register in the processor 52 is set aside to operate as a Continue Address Register (CAR). For example~
the CAR can be two bytes in length and can be used as an accumulator in which the previous contents of CAR are summed .. . .. . . .. .. ... _ .... .. .. . ... .. ..... .... .. . . ... .. . . . ... ..... .. .. . .. . ....... ... .. . .
. . . . . ...... ..

with a unique quantity r~presenting a key code to derive a new CAR quantity. In order to insure that the CAR r~g ister maintains a relevant quantity, it is cleared ~set) to a value of 1 on power on, or activation of a key cor-responding to a function, numeric~ sym~ol and most punc-tuation marks.
For repre~enting each different keycode ~or purposesof decision tree processing, any unique numeric quantity can be assigned to different key codes, for example, the keycode itself may be u~ed as a numeric quantity. For purposes of explanation, we will assign, in se~uence, even numbers beginning with 0, ~or keycode corresponding to A, through the numeric quantity 50 ~or the keycode corresponding to the character Z, Thus, the characters C, E, N, o, ~ and X correspond to the numeric quantities 4, 8, 26, 28, 34 and 46, respecti~ely.
When the automatic word ending operation is initiated, the C~R includes a quantit~ o~ 1, since it is cleared to that state on power on or selection of any function, numeric or most symbol gxaphics. A further register in the proces~or 52, the Retrieval Address Register (~AR) i5 initially loaded ~ith the address at which the keycode corresponding to the automatic word ending key entry is stored. This address is then decremented by 1 90 as to address the immediately preceding location and the cor-responding keycode quantity (for example C) is extracted and added to the CA~. Thus, the ~ntries shown in Fig. 6in the Continue Ta~le 1 are located at addxesses of 5, 9 27, 29, 35 and 47, respectively~
In the course of processing, ~hen the continue flag combination lQ is detected (~or example C)~ the RAR is again decremented so that it points to the lmmediately pre~
ceding character. At the same time, the flag bits are stxipped from the contents of the location and the pointer located there is inserted into the CAR, and that quantity is summed with the quantity corre$ponding the keycode pointed to ~y t~e R~R so as to point to a specific loca-.. .. . . .. .. .. . . . . . . .. . . .. . . . . .

-~ ~ ~7~6~
- 2~
tion in the next appropriate table.
In this fashion, the table entry of a nods is se-lected ~as~d upo~ the character, and if that information is inadequate to determine an appropriate word ending, the contents of the Table point to another Table, and a specific entry in that table is located by the quantit~ correspond-ing to the immediately prior character. This pxocessing continues in serial ~ashion until a de~ault entry is de-tected or a contin~le flag no combination is detected ~hich indicates that the corresponding pointer points to the representation Qf an appropria~e word ending.
In order to decrease the processing time, and the nec-essary storage, the generation of a pointer fxom one table to anothar can ~e preceded by a test to determine if the preceding character corresponds to a specific entry in the table. If it does not, then a default can be indicated, thus saving space otherwise required fox storage of plural default indications.
Once a flag combination 00 is detected, indicating that the associated entry represents a word ending, a further reserved area can include representations of the character identifying signals necessary to drive the display to out-put the desired word ending. However, this would duplicate the function control storage area of the read onl~ storage 53. Therefore, preferably, each table entry associated ~ith the flags 00 can comprise a start address which refers to a sequence of pointers, pointing to the desired charac-ter identifying signal stored in the ~unction control storage area of xead only storage 53. Once the start ad-dress is obtained, and the corresponding character identi-fying signal extracted from the function control storage area; the start address is incremented and the process is repeated for the next charactex identifying signal~ in se-quence, until a stop code is detected~ Thus, for example~
Figure 8 illustrates three reserved areas in the read only storage 53 pointed to by staxt addresses ~or the "ceed", "cede", and "sede" word endings. Accordingly, ea~h start add~ess is a representation o~ the associated woxd ending.

LE~-78-~37 , .. . . . . .. . . .

1 ~S75~7 Figuxe 7 is the pxocessing ~outine exe~uted by the processor 52 when automatic word endin~ ~per~tion is ini-tiated on decoding of the keycode for an automatic ~ord ending key actuation. A~ described above, this can be based on the unique keycode, i.e.~ or a single purpose S key, such as the ke~ 11, shown in Figure 3~ or the key 12 or 13, shown in Figure 3B. On the other hand, auto-matic word ending operation can be înitiated based upon decoding of a multi-purpose keycode~ such as that of key 35 (Figure 11 or one of keys 28, 20 and 30 ~in Figuxe 2), in the simultaneous pxesence of the set condition of auto~
matic word ending mode latch.
Finally, auto~atic word ending can be initiated by de-code o a multi-purpose key ~i.e. key 35) coupled ~ith the condition that a previous key entry was a chara~ter (or one of a set of specific characters~.
I~, for example, a multipurpose key is employed without use o~ a mode changing key and no allowable word ending is found the text recorder is allowed to output the character/function associated with this ke~ which is not an automatic word ending function, see page 22 Regardless of the manner in which entry into auto-matic word ending operation is initiated~ the ~irst func-tion, function 100, stores the present memory address (contained in MAR) in the RAR. The present memory address is the address in the keycode storage, at which the key-code c~rresponding to the automatic word ending key actu-ation is stored. Function lGl then decrements the ~uan-tity in RAR, thus, RAR points to the keycode stored prior to actuation of the automatic word ending key. Function 102 then retrieves the code quantity from the keycode storage area in R/W storage 510 Function 103 then tests the entry to deter~ine if it is an alpha key. Assuming it is an alpha key, then function 104 adds the keycode or the corresponding unique quantity to the CAR. As will be seen hereinafter~ the contents of CAR prior to per-LE~-78-Q3~

~ ~S7S6~
- 2~ -forming function 104 was the quantlty 1. Function lOS
then employs the qu~ntity in C~R as an addre3s into read only stoxage 53. Function 106 detects the continue flag combination. If the continue Elag combination is 00, then S function 107 is performed to extract the start addxess inasmuch as the desired word ~ndiny has been identified.
Function 108 begins with the start address and outputs the character identifying signals by using the appropriate reserved area as shown, for example, in Figure 8. Func-tion 109 then sets the CAR to a quantity 1 and that con-cludes the processing.
Function 108, in processing the desired word ending, can then fill the sequence of character identifying signals corresponding to the desired word ending into the keycode storage area (or into an output buffer~ just as if the operator had actuated the corresponding keys.
The first character identifying signal is inserted into the space located by the Memory Address Register,(MAR~
which is thereafter incremented. Each succeeding charac-2Q ter identifying signal is similarly stored until the stop code is detected.
Assuming, however, that the continue flag was not 00, then further processing may be required. Therefore J func-tion 111 removes and saves the continue flags ~or reasons which will be explained. Function 112 then replaces the old quantity in CAR with the ~uantity obtained from the continue table at the location addressed. Then the rou-tine loops back to function 101 to decrement the RAR and con-tinue processing.
If, at test 103, the entry pointed to by the RAR
is not an alpha key, then test 113 determines the status of the saved continue flag, saved at function 111. If the continue flag had been 01, indicating that processing was continuing, the unique keycode associated quantity is s~mmed to the contents of the CAR at function 114 to develop a pointex to a further table. A short example will su~fice. Con~ider the words accede and ostracize.
Each word ending is preceded by "ac", however the word .. . . . .

l 1S7~67 endings can be differentiated by examining the keycode preceding the "ac" combination. If a space, then word ending cede is appropriate, if an "rl' then the ize ending is appropriate. In the first case the continue ta~le entry pointed to by the sum of "a" pointex and space func-tion code would identi~y the the cede word ending. Inthe second case the sum of l'all pointer and the "r" code would point to the ize ending. In the absence of an 01 flag combination, detection of a non-alpha keycode in dicates a default at test 113.
The routine continues at function lOS and obtains the new continue table entry at the address corresponding to the contents of the C~R.
If at any time the continue flags saved at function 111 correspond to 11 (indicating a default~, on the next or a succeeding pass through the routine at which a non-alpha keycode is found, at decision point 113, it will be determined that the continue flag is not 01, and therefore, a default will be noted, at function 115.
Alternatively, a second test can be used on the no branch of function 106, to test for a default condition.
Depending upon other constraints, the default can be handled in one of a number of ways. It may, for ex-ample, simply result in no operation indicating to the operator that, for some reason, the text recorder is in-capable of automatically completing the word, and there-fore, requires the operator to do so in a con~entional fashion. In other circ~nstances, where for example, the key which actuated the automatic ~ord ending opera-tion is a dual purpose ke~ it may merely indicate that automatic word ending is not appropriate and another func-tion associated with that key should be employed or a character associated ~ith that key should be displayed in lieu of a word ending.
Based on the ~oregoing explanation, we can now describe opexation of an automatic word ending text re~
corder, operating with a keyboard of the type shown in Figure 3B. For this example, we assume that the operator .

has previously keyed in several characters and no~ wishes an automatic word ending to be selected corresponding to that associated with the key 12, and therefore, thi~ key is actuated.
When the key 12 is actuated, the keycode is gener~
I ated in the keyboard interface 1, and coupled through the ¦ data lines to the processor 52. Processor 52 determine~
¦ ~hat the key is an automatic word ending key by any con-i ventional decoding steps. Upon recognizing actuation of the automatic word ending key 12, the program steps of I Figure 7 are initiated. After processing one or more pre-¦ vious key entries as outlined above, a continue table en-try is read which has the 00 flags indicating that the associated quantity is a start address. This address is passed to the character processin~ routine of the type shown in Figure ~, in the above-referenced application.
Briefly, this routine merely retrieves the character identifying signals stored either directly or indirectly at the addressed location and increments the addressed location and continues retrieving character identifying signals until a stop code is detected. In this connec-tion it should be noted that it ma~ be desirable to include a space function at the conclusion of the last character and before the stop codes so that the automatic word end-ing text recorder will not only display the appropriate word ending, but also provide the space function between the word and the remaining text.
operation of a keyboard such as that shown in Figure 3A is identical except that the decision tree is 3Q amended to include the other possible ~oxd endings and correspondingly, the continue tables are supplemented with the necessary entries.
Operation of an automatic word ending text recorder with a keyboard such as that shown in ~igure 2, requires few additional modifications. Firstly, an automatic word ending mode latch must be added and controlled as is dis-closed in the above-referenced application for the multi-character mode latch. Each of the keycodes ~or keys . . .

i 1~7~7 - ~7 -28-30, when decoded in the presence of a set condition of the automatic word ending latch, will result in actuation of the automatic word ending operation. That equipment is identical to that described in relation to the keyboard of Figure 3B with the further exception that a different set of continue tables are provided for each of the keys 28-30. Finally, the operation of the keyboard such as that shown in Figure 1 requires a con-tinue table appropriate to the additional word endings, and the use of an automatic word ending latch so that when the keycode of key 35 is decoded in the presence of a set condition of an automatic word ending latch, automatic word ending operation is initiated.
This first group of embodiments of the invention is employed with the retrieval address register (RAR?
which is used to point sequentially to the previously entered keys in the keycode buffer in the reverse se-quence in which those keys were first entered into the buffer. ~ continue address register (CAR) is employed to point to one of a sequence of continue tables, and the entry in the continue table is selected based upon the identity of the previously entered character, the result of that entry is either a pointer to a next con-tinue table or a word ending start address. The process repeatedly adds a unique quantity corresponding to a retrieved keycode to the continue table pointer to locate an entry in the table. This operation continues until either a default condition is determined or the start address of a word ending is located, ~LPH~ SEQUENCE ID EMBODIMENTS
In another group of embodiments of the invention, a quantity is built up in an accumulator, termed the alpha sequence identification accumulator (or register) which, when the automatic word ending key is actuated, points directly to the start address of the associated word end~
ing. To effect this, as each keycode is entered a unique : . . . . . . . . . . . . .

~ ~57~67 quantity is added to the alpha sequence identiflcation accumulator. Upon the occurrence of most numeric, func-~ion or symbol graphics, the alpha sequence identiication accumulator is cleared to zero and a new sum is accumu-lated on the next entry of a cha.racter key. So long a~
the different word endings are pointed to by a unique `
alpha sequence identification, the automatic word ending can be selected and output. In the event that an alpha sequence identification is provided which does not cor-respond to a start address of an automatic word ending~
then a default condition is indicated.
Although the only constraint UpOII the numeric quantity assigned to the different keycodes to differen-tiate them is that they be unique, for purposes of the present example, we will assume that the keycode ~or each of the 26 alph`abetic characters comprises an ordered se-quence from 1 to 26 wherein the quantity associated with character A is 1 and the quantity associated with the chaxacter Z is 26.
Table 1, reproduced below, compares the alpha se-quence ID with the different word endings for the group of word endings comprising "sede", "ceed" and "cede". It will be seen that the alpha sequence ID 79 is the only one . corresponding to "sede" and alpha sequence ID cor.responding to "ceed" is 29, 49, or 43, and the other legal alpha se~
quence identi~ication numbers 40, 4, 32, 66, 39, 23 and 24 all correspond to the word ending "ceed", The alpha se-quence ID can be us~d directly to enter a table of start~
address pointers, or other conventional addressing tech-- 30 niques such as indirect and relative addres.sing techniques can also be employed.

LE~9 78-037 : . .
.. : . . .. .... .. . . . . . . . .

TABLE I
CHARACTERS ENTERED SUM WORD ENDING
S U P E R S E D E
19+~1+16~5+18 =79 S E X C E E D
5+24 =29 P R O C E E D
16+18+15 =49 S U C C E E D
19+21+3 =43 A N T E C E D E
1+14+20+5 =40 A C C E D E
1~3 = 4 C O N C E D E

3+15~14 =32 I N T E R C E D E
9+14+20+5+18 =66 P R E C E D E
~o 16+18+5 =39 ' R E C E D E
18+5 =23 S E C E D E
19+5 =24 LE--g--78-037 i ~ . . . . .
, ~ ~57567 Figure 9 illustrates the scheme employed. More particularly, when automatic word ending operation i5 ini-tiated, the alpha sequence identification register contents are used as an address into the word ending s~lection table~ to identify a number of start addresses which, in turn, refer to a charactex sequence table at which representations of a plurality ~f groups of word endings are provided, each group including a sequence of character representations in the sequence in which they are used in the word ending.
Since it can be foreseen that a hyphen may be a legal character in a word, it is important that entry of the punctuation graphic corre~ponding to a hyphen does not clear the alpha sequence identiication register. To this end, the key entry processing includes a test for a hyphen key and, when such a key is detected, the alpha sequence identification register is not cleared but the sum is maintained. Furthermore, detection of actuation of the hyphen key also protects the alpha sequence ID register from being cleared by a suhsequent carriage retuxn ~unc-tion, for the same reason.
Figure 4B is a block diagram of an embodiment of theinvention, similar to 4A, except that some oE the tables in ROS 53 and registers in processor 52 have been changed.
The read only storage tables required for this operation are the sequence of character sequence tables, and the .single word ending selection table. In the event that the alpha sequence quantity associated with each keycode is not the keycode itsel~ or some quantity which is contained within the keycode, a fuxther table may be required in the read only storage to translate keycode into alpha se-quence identification quantities for summing in the alpha sequence register.
In the processor itself, the RAR and CAR can be eliminated and instead an alpha sequence identification register and h~phen flag axe maintained. The processing routine is illustrated in Figure 10.

.. . . . . . ..

1 ~57~7 In connection with the discussion of Fi~ure 10, we will describe an example in which an operator keys in the alpha se~uence "ex" and then keys in an automatic word ending key. For example, in connection with the keyboard Figure 3B, that operation corresponds to actuation of key 12 or 13. Similarly, in connection with the keyboard of Figure 3A, actuation of key 11 initiates automatic word ending operation. Actuation of key 35 ~Figure 1~ or keys 28-30 (Figure 2~ will initiate automatic word ending operation in the event the automatic word ending latch is set by the previous actuation of key 38, Proceeding with the example, when an operator actu-ates the "F." ke~, function 200 detexmines that the entry is an alpha key. Function 201 then obtains the alpha key number, As explained, this number might well be the key-code itself, or a quantity which is derivable from the keycode and either comprising a portion of the keycode or related to the keycode through the use of a table. In the example in disussion here, the alpha key nun~er for this key is the quantity 5. Function 202 then sums the alpha key number in the alpha sequence ID~ As will be-come clear hereinafter at this point in the processing, assuming the letter "E" is the first letter in the word, the alpha sequenc~ ID would have ~een cleared to 0, and therefore after the summing operation of function 202 r the alpha sequence ID would contain the sum 5~ Function 203 resets the hyphen flag, the reason for which will become clear as this description proceeds. Function 211 then represents conventional key entry processing to display the character corresponding to the actuated key~ When that has been concluded, function 212 returns to process the next key actuation.
In accordance with our example, the next key actu-ation is the "X" key, and the same processing is performed~
As a result of function 202, the sum in the alpha se-quence ID register follo~ing that function is the sum 29, and at function 211, the corresponding character is ~is~
LE9 78-~37 ... .. .

1 ~57567 played and at function 212, the process returns to await the next key actuation.
In accordance with our example, we assume that the operator now actuates a key initiating automatic word ending operation. Thus, function 200 determines the entry is not an alpha key. Function 204 determines that the entry is not a hyphen key. Function 206 determines that the entry is an automatic wo~d ending key. Function 208 checks if the alpha se~uence ID was 0, since in our ex-ample it is not, function 214 uses the alpha sequence as a pointer to a selection table to obtain a start address located in that table (see Figure 9~. Function 215 uses the start address as a pointer to a character sequence table (see Figure 9) and function 2~6 processes the chaxac-ter string represented in the character sequence table beginning at the start address obtained at function 214.
The processing necessary to display the charactex string is described in detail in the abo~e-referenced ~pplication (in connection with Fig. 9~. Function 217 then resets the alpha sequence ID to 0 and function 212 returns the pro-cess to respond to the next key actuation.
In order to illustrate the use of the hyphen tests, we can modify the example described above to assume that the operator keys in the sequence "EX~" and a carriage return before actuating the automatic word ending initiat-ing key. The processing of actuation o~ the "E" and "X"
keys proceeds in the manner explained above~ Upon actu-ation of the hyphen key, function ~00 determines that this entry is not an alpha key, but function 204 deter-mines that the entry is a hyphen key. Accordingly, func-tion 205 sets a hyphen flag and function 211 processes this key entry to display the hyphen.
The need for the hyphen flag comes about when a function ~ey is executed, such as a carriage returnJ platen index or the like. To illustrate the ~oint, let us assume that the operator next initiates a carriage return.
Function 2Q0 determines that t'ne entry is not an alpha key and function ~Q4 determines that the entr~ is not a .. . ..

~ ~57~67 hyphen. Function 206 detexmines that the entry is not the automatic word ending operation key/ and ~unction 207 determines that the entry is indeed a function. Decision 203 determines that the hyphen flag is set, and there~
fore, the key entry is processed at function 211 Had the hyphen flag not been set, then function 210 would reset the alpha sequence ID to 0. Thus, setting of the hyphen flag prevents clearing of the alpha sequence ID in re-sponse to a function actuation. This serves to retain the alpha sequence ID sum so that the sum actually em-ployed to access the word ending selection table is that related to all characters in the word prior to the word ending rather than only those characters on one line.
The preceding embo~iments of the invention, i.e. r those employing decision tree processing ~those disclosed in connection with Figures 4A, and 5-8~ and the embodiments of the invention employing the ID sequence register (disclosed in connection with Figures 4B and ~-10l, carxy storage re-quirements or processing requixements (~or a given en-2~ semble of word endings) which can be reduced by carefultailoring of the processing and the stored tables employed with the processing~ by correlating the selections that must be made, and the information which is av~ilable to make those selections. The embodiment of the invention which will now be disclosed is a blend of the techniques from the previously disclosed embodiments, chosen so as to reduce the amount of storage tables requîred, and also to minimize the processing required in order to make an appropriate selection. Before disclosing the implementation of this embodiment, the basis upon which the tables and processing are based will be des~ribed.
We take as an example the selection to be made among the "sede", "shun", or "ize" sounding woxd endings based on preceding characters. Each of the 'Isede'l and l'ize" word endin~s include three distinct vex$ions~ and the "shun' sounding word ending includes two di~ferent versions~
LE~-78-Q37 .. . . . ... . . .. . . . . . . . . . .

1 ~575~

- 3~ -for a total of eight possible woxd endings. Appended -to this application as Appendix A is a relatlvely complete list of word endings arranged by pxeceding character, i.e~, the character prior to the word ending. Thus, from Appen-dix A it will be se~n that the word endings following thealphabetic character "a" are only the "shun" endings, and of which the vast majority are "tion" ending, only four words in Appendix A have a preceding "a" character and the "sion" ending~ Appendix A lists other possible word endings in order o the preceding alphabetic character.
One designator, to select among possible word end-ings is the alpha se~uence ID. Thus, each alphabetic character (or the corresponding key code) is given a numerical weight, just as in one of the preceding embodi-ments of the invention. However, rather than employing anordered weighting, the weightings listed in Table II is employed~
TABLE II
ALPHA NUMERIC ALPHA NUMERIC
KEY VALUE KEY VALUE

F, 1 R 18 I 9 ~ 22 J 1~ W 23 Appendix Ar in addition to identifying each immediately pre-ceding character with one of the selected ~ord endings, also lists the alpha sequence ID value for that word~ O

LE~-78-037 .. . . . . .. . . . . . . ~ .. ~

~ 1575~7 course, the alpha sequence ID value is the sum of the weightings for each alphabetic character preceding the word ending. Thus r for example, the word "abrasion" has an alpha sequence ID value of 72, corresponding to 26 (a) + 2 (b) + 18 (r) + 26 (a). While we have employed the particular weighting shown in Table II, those skilled in the art will understand that other weightlngs could similarly be employed with appropriate modification made to the tables which will be disclosed hereinafter.
An additional indicator, assistin~ in the designa~
tion of the appropriate word ending, is the alphabetic character immediately preceding the desired word ending.
Figure 11 is a frequence of occurxence table correlating the alphabetic character preceding the word ending with the associated or appropriate word ending or endlngs.
Figure 11 illustrates, for example, that certain o~ the alphabetic characters do not precede any of the allowable word endings (B-F-J-K-Q-Y~Z~. While, on the other hand, certain alphabetic chaxacters precede only one ~ord end-ing (G-V-W-X~.
2Q Accordingly, the processing is simplified when auto-matic word ending is initiated by reviewing the identity of the immediately preceding alphabetic character using a character preceding table (CPT~. If the alphabetic character is one of the first mentioned group, then the default selection can be immediately made because no amount of processing will produce an appropriate word ending. On the other hand, if the immediately preceding alphabetic character is one of the second mentioned group, then the appropriate word ending can be immedia'cely de-3~ termined from the identity of the preceding alphabetic character.
The remaining processing is employed to handle the situation when the immediately preceding alpahbetic charac~
ter is not in either of the two groups outlined above.
Those cases relate to word endings for the immediaieiy preceding characters a,c,d,e,h,i,l,m~n,o,p,~,s,t, and u.

L~9-78-~37 I ~575~7 At this level of processing, the processor has identified the immediately preceding alphabetic character and also has available to it, for the alpha ID sequence register, the word value o all of the characters in the S word preceding the desired word ending. Thus, assuming that the processing has determined that the im~ediately preceding character is not one of either of the two groups mentioned a~ove, then an alpha table is selected based upon the immediately preceding charactex. Enter-ing the selected table at a location determined by thealpha sequence ID will, in most cases, identify the desired word ending. The necessary string of character and function identifying signals can be produced using techniques described in connection with other embodiments of this application from single address ~hich is determined from the table.
In some cases, however, conflicts exist in that certain words, having identical alpha sequence ID quanti~
ties and identical characters preçeding the ~rd ending, actually employ different word endings, and thus additional information is required in ordex to make the desired selec-tion. Table ~II lists these conflict situati~ns for the words and endings of Appendix A.
TABLE IXI
A-TION ALP~A SEQUENCE XD
cancellation 101 computation 101 identification 101 modernization 101 toxication 101 vaxiation 101 persuasion 101 designation 72 gyration 7~
abrasion 72 obligation 67 LE~-78-037 , . _ _ . A . . , . _ . . _ .. . .~ ~

~ ~575~7 TABLE III ~Continued) A-TION ALPHA SEQUENCE ID
invasion 67 C TION ~LPH~ SEQUENCE ID
. . .
5 induckion 51 exercise Sl action 33 accede 33 N-IZE ALPHA SEQUENCE ID
reorganize 91 interVention ~1 mechanize 65 convention 65 S-SION ALPHA SEQUENCE ID
submission 83 empha~ize 83 con~e~sion 58 ~uestion 58 2Q Cons~der, ~or example, "variation" and "per uasion". Each has the alpha se~uence ID 101 and the alphabetia charaater "a" precedln~ the word ending, but o~ course~ the first hag the "tion" ending and the second has "sion ending.
Accordin~ly, additlonal pXoaes~ing is required to 25 resolve the~e con~lict~. Obviou~ly r in this conflict ituation, the inform~tion concarning the alphabetic charactex preceding the ~ord ending, and ~he alpha se-quence ID as~ociated with the word i8 simply lnadequate to make the desired selection~ Therefore, in the~e spe-ci~io situatio~s, additional tabl~s are xequlred J based on t~e3e ~pecific words~ and employing ln~ormation con cerni~g one ox more o~ the cha~a~tex~ ~rec~ding the charac-ter~ immediately precedi~g he automatic word ~nding~ to make the d~ired ~el~atio~.

: ~E~78-037 .. ~, ,, . . ... .. ~ . . .

i ~575~7`-This additional ta~le (exception table~ includes one entry fox each conflict situation. The alpha table~
which identifies a conflict also points to the entry in the exception table which can xesolve the conflict.
Rach entry in the exception table includes a pointer for each of the word endings making up the conflict and a data item with which to resolve the conflict. Preferably the data item will be a selected character in a word with one ending but not appearing in the word with the other lQ ending. For example, consider the words "persuasion" and "variation". Each has a different word ending, but each word has the identical character ta) preceding the word ending. Furthermore, each word had the alpha se~uence ID
of 101 - thus a conflict. Since both words have the same character preceding the word ending and both have the identical weight, some other distinguishing characteristlc is required. In the embodiment to be disclosed the dis-tinguishing data item is the first character "p" in per-suasion but not "p" in "variation". Thus~ the exception table data item can be compared with the first character of the word selected by the operator. This character is stored in a first entry register, in a mannex to be ex-plained. If comparison of the fixst entry register con tents and the exception table data item gives one result (favorable or unfavorable~ then one word ending is selected and vice versa. There is no requirement that the data item correspond to the first character although that is pre-ferred for simplicity purposes. Indeed, the data item can be any item capable of distinguishing the conflict words. For example~ rather than the first character, it might be the first char~cter pair, or other character com-bination. However, the data item need not even be related to the identity o~ one or more characters preceding the word endin~ for it might be the number of characters pre-ceding the woxd ending~

- 1 ~57~7 - 3~ -Within the example lndicated, the proce~sing steps and tables are ade~uate to make the desired selection in every case, axcept one. The words "action" and "accede"
have the identical prefix 'lac"~ Accordingly~ no amount of processing can select the appropriate word endings since there is simply inadequate information to make the selec-kion. Two alternatives are available; the first alterna-tive is to merely indicate to the operator that this is a default condition and automatic word ending is simply im-possible, thus requiring the operator to key in the appro-priate word ending; on the other hand, by appropxiately modifying the pxocessing tables disclos~d herein, the automatic word ending could be semi-automatically produced by requiring the operator to select the first character of the word ending (that is, the "t" for action and "c" ~or accedel, or by insuring that the initiation of automatic word ending operation distinguish bet~een the "shun" and "sede" word endings.
Thus~ in accordance with this embodiment of the in-vention, as the operator keys in alphabetic characters in a word, identification of the characters (according to the keycode or similar uni~ue charactPr designationl is stored in the buffer in the order in ~hich it is entered ~and in accordance with conventional techniques the cor-responding character is displayed or printed~. At thesame time, the first entry register is loaded with first character information and an alpha sequence ID register accumulates a quantity corresponaing to the alphabetic character weightings in accoxdance with that shown in Table II, for example. When an automatic word ending operation is initiated, for example, by depression of a single or multi~purpose key under the appropriate circum-stances, the proces~ing logic, based on the preceding alphabetic character, refers to a character preceding table ~CPTl. This table has thxee different types of ~ 1~75~7 -- g o ~
entries. A first type of entry in the table is a de-¦ fault entry associated with each alphabetic character which does not have an allowed automatic word ending in the dictionary of automatic word endings; a second type of entry in the CPT table is a start address, i.e., an address at which is stored a pointer designating (or rep-resenting~ a particular one oE the available word endings, and the third type of entry is a pointer to an alpha table associat~d with the preceding alphabetic character.
lG When the preceding alphabetic character points to either the first or second type of entry in the CPT table, the processing is, in effect, concluded, since a selection has already been ef~ected that no allowable word ending exists, or of the appropriate word ending. Only when the entry in the CPT table is to another table must sub-stantive processing continue.
Each pointer in the CPT table which points to an-other table points to one of a number of alpha entry ad-dress tables.
Each alpha entry address table is firstly associated with a diffexent one of the possible alphabetic charac~
ters immediately preceding automatic word endings, and each table includes plural multi-word entries. Each en-try includes a quantity corresponding to the alpha se-quence ID for an associated word, an address pointer which points either to a representation of a selected word end-ing (i.e. a sta~t address~ or a pointer to a further table, the exception table. When processin~ employs one of the alpha entxy tables the logic increments through ~he table~
starting at the beginning of the table~ looking for an e-qual comparison between th~ alpha sequence ID contained in the alpha sequence ID register, and the entry in the alpha table. One of the two fla~s in each entry is the "last compaxe fla~" which indicates that if a comparison is not effected~ then the last entry in the table is the .

l 1~75B7 pointer to the associated worcl ~ndln~.
When a compar.ison is effected between the ~uantity in the alpha sequence ID register and the ~uantity in the alpha table entry, then the further ~lag is checked, the exception flag. The exception fla~ identifies those conflict situations which are illustrated in Table III.
When an exception flag is on, further processing is re-quired with reference to an exception table, and the alpha entry table provides a pointer to the exception table.
Each entry in the exception table corresponds to a dif-ferent one of the exceptions of Table III~ If the last compare flag is set then by comparing the data item in the appropriate ex~eption table entry with the contents of the first entry register the proc~ssor can determine which of the word endings associated with the entry is appropriate. Additional processing is required if there is more than two word endings to select from in an exception group~ In particular, the processor must increment through an entry in the exception table to determine an appropriate word ending by comparing the exception table data item and the contents o the first entry register~ Once such a determination is made the corresponding character signals are extracted using the proper pointer also included in the exception table entry.
Figure 4C is a block diagram of the apparatus employed in this embodiment of the invention. Reference to Figure 4C illustrates that it i5 similar in fo.rmat to Figure 4A
and 4B but that some of the tables in the read only storage 53 have been altered as compared to Figures 4A and 4B t and that the processor 52 includes several registers and other hardware devices specific to this embodiment. Before de-scribing the processing logic employed, the several tables contained in the read only storage 53 are described.
Figure 12 illustrates the Character Preceding Table (CPT~. This table has 26 entries~ one corresponding to each alphabetic character Outside the table, under the column headed "Numeric Code Address" are three columns;

1 ~57~7 - ~2 -a first column indicating the relative addr~qs o~ ~ach entry in the table, relative to the table's base address (K), the second column indicating the absolute address of each entry in the table, and the third column indicating the preceding character whose detection leads to entry to the table. Inside the table, the phrase describes the meaning of each table entry, while the numeric quantity in parenthesis is one example of what the table could actually contain. For example, the first entry in the table corresponds to an alpha table pointer for the E
alpha tab1e and this pointer actually comprises a numeric quantity 41. Similar pointers are included for the charac-ters D,C,H,I,N,L,M,O,P,R,S,T,U and ~. Reference to Figure 11 indicates that it is exactly these characters which are the preceding character to at least two differ-ent word endings, and therefore, the read only storage 52 includes an alpha entry table for each charactex. The second type of entry in the CPT table is a start address, and start addresses are provided corresponding to the pre-ceding characters G,V,W,X, respectively. Reference to Figure 11 indicates that it is just these characters which are the preceding characters to only a single woxd ending.
Accordingly, the corresponding CPT entry provides a pointer to the start address location for these different word endings, and thus each start address is a repxesentation of the associated word ending. Finally, a third type of entry in the CPT table is a default entry, and default entries are provided corresponding to the character pre-ceding a word ending for the characters B,Z,E',K,J,Q, and Y.
Reference again to Figure 11 indicates that it is just these characters which do not precede any woxd ending in the ensemble of word endings which can be automatically provided by the equipment. The default entry can com-prise any type of entry which the processor 52 will recog-3s nize as signaling a default, for example~ a numeric quan-tity of zero can be employed, alternatively various flags ~E9-78-037 .. . .. . . . . . . . . . . . . . ..

7~7 - ~3 -could be employed.
Figures 13A through 13D illustrate respectively the format for each entry in the alpha table, as well as each alpha table employed. Referring first to Figure 13A;
! 5 an entry usually comprises two words, the flrst word cor-responding to the alpha sequence ID, and a second word made up of two flags, a last compare 1ag and an excep-tion flag, and an address pointer. Each alpha table may include a plurality o entries, one for each different word having a character preceding the word ending identi-cal to the character which is associated with the table.
The address pointer portion of the entry is a start address pointer/ if no conflicts exist (a conflict is defined as a situation in which the alpha sequence ID and the charac~
ter preceding a word ending are identical for two dif-ferent word endings~. In the event that a conflict situ-ation exists, then the address pointer, rather than repre-senting a specific word ending, points to a location in an eXception table which is employed to resolve the conflict.
When the address points to an exception table, the excep-tion flag is set, otherwise it is not, The next to last entr~ in each alpha table has the last compare flag set, otherwise the last compare flag is not set. This is em-ployed in processing thr~ugh an alpha table to indicate that when the last compare flag is ~ound set, the next entry pxocessed is the last entry in the ta~,le~ This feature enables a large reduction in the extent of the table, as will ~e described, The last entry in each table omits the alp~a sequence ID word, and the flag bits may 3Q be i~nored.
Referring now to Figure 13B, the alpha tables for the preceding c~aracters "A", "D", "E"~ "~", and "C" are illustrated~ Refexring to the A alpha table, the woxd of the first entry is an alpha sequence ID of lOl. Note that the eXception flag is set for this entry indicating a conflict. Thus, the numexical ~uantit~ occup~ing the .

~ ~ ~75~

address pointer location can be employed as an entry in-¦ to the exception table so as to resolve th~ con~llct.
Referring back to Tabel III, lt will be noted that the I alpha sequence ID of 101 is identical for words with 1 5 the character preceding the word ending "A" ~or either the ~tion~ or ~sion~ word endings. Thus, the conflict must be resolved hy ~urther processing. On the other hand, the first memory word of the second entry in the alpha table for "A" has an alpha sequence ID 55 and an ex-ception flag which is not set. Thus, the numerical quan-tity in the address pointer location for this entry is a pointer to the "sion" word ending, and indeed, actually represents that particular ending. We can refer to Appendix A, for example, to verify that the alpha se~uence ID 55 corresponds to the word occasion.
Referring to the next entry in the alpha table, note that the exception flag is again set. The alpha se~uence ID 67 corresponds, according to Table III to either the words obligation or invasion, and the pointer "6" can be used to address the exception table to enable resolution of the conflict.
The next to last entry in the alpha table has an alpha sequence ID value 72, and the exception flag is again set. Referring to Table III, we see that the value 72 can correspond to either the "tion" or the "sion" end-ing, and therefore, the pointer "3" provides a reference to the exception table to resolve this conflict. Note that this next to last entry includes the last compare flag set also. Accordingly, the next entry in the alpha table is but a single word long, i.e., it does not have alpha sequence ID; it m~rely has a representation to a specific word ending. This illustxates an important advantage of this type of table. Figure 11 indicates that word endings pr~ceded by the alphabetical character "A" are either "sion" or "tion", four words falling into the first .

and 156 words falling into the second. The alpha table illustrated in Fi~ure 13B calls out each of the potential conflicts/ i.e., alpha sequence ID values of 101, 67 and 7?. as a specific entry, one entry for the one unambiguous "sion" word ending, and then rather than having an entry for each of the other 153 "tion" endings, a single entry suffices inasmuch as each of those words have the identi-cal ~Ition~ ending.
This is clearly illustrated in connection with the "L" alpha table, shown in Figure 13C. Reference to Figure 11 indicates that there are 49 different words in which the character preceding the word ending is "1", two of those employ the "yze" ending and the rest employ the "ize" ending. The "L" alpha table has but three entries, two corresponding to the tw~ specific "yze" endings, and a third handling all of the 47 "ize" endings. From the foregoing the contents and creation of each of the other alpha tables is believed apparent and therefore no further discussion is provided~
Figures 14A and 14B illustrate respectively, the for-mat for a typical entry in the exception table and the table itself. A first word includes a paix of flags, the last com-pare flag and the exception flag, and an alpha numerical value corresponding to the first character o~ one o~ the two words having the different endings. The different endings are represented by the pointers in the second and third words of each entry. Thus, for example, the first entry in the Excep~ion Table has a nu~erical value 16 in the first word corresponding to the alphabetic character P.
The first of the two pointers associated with this entry is a pointer to the word ending "sionl'. Thus, when this entry of the table is accessed~ the numerical quan-tity in the first word of the table is compared to the first entry register (which is loaded in a manner to be explained hereinafter~ the comparison indicates they are identical, then the first pointer employed~ i~

.. . . . . . . .

~ ~57~67 the comparison does not indicate A comparison, the ~ec-ond pointer is employed. Each of the other entries in the Exception Table are similar except for the entry cor-responding to preceding character with the ID value 33.
It has already been noted that the word ending for the words "action" or "accede" cannot be determined by refer-ence to the characters preceding the word ending, since they are identical (both use the preceding characters "ac"~. Thus, this particular entry includes a set ex-ception flas, and may also include a default entry ratherthan a pointer, to indicate that the exception condition cannot be resolved. While each example in the Exception Table (Fig. 14B~ has only two word endings to choose from, it is conceivable that a conflict may exist between more than t~o possible word endings. In that case the Excep-tion Table entry ~ould include a pointer ~or each member word ending of the group and enough data items for com-parison to allow the appropriate ending to be identified.
Figure 15 illustrates the word ending Output Table.
This table includes an entry for each different word end-ing. The table shown in Figure 15 includes accessible ad-dresses (relative to a ba~e address~ of 227 (for the word ending "sede"~ 231 (for the ~ord ending 7'cede'l) 235 (,or the word endin~ "ceed") 239 (for the word ending "yze") ~5 242 (for the word ending "isel'~ 245 (for the word ending "ize"~ 248 (for the word ending "sion") and ~52 (for the word ending "tion"),. When a start address is passed, each associated pointer is extracted, and used as a pointer into the function contxol storage at which was st:ored the charac-ter representing signals. Alternatively~ th~ character representing signals could be storad in the word ending output table, if desired. The additional bit, stop bit equals one, is stored with each polntex to the last charactex of a ~oxd ending to indicate to the processor that the ~ord ending is complete~ Optionally, the woru LE~-78-Q37 .. . . . .. . . . .. . . .. . . . . .

1 ~7S~7 ¦ ending can conclude with a space (or space pointer) ! following the last character and accordingly, the stop I code is associated with the space (or pointer).
Finally, Figure 16A through C illustrates the pro-cessing ~arried out by the processor 52 in connection with this embodiment of the invention.
When the processor 52 recognizes an actuated key, I function 500 stores, in RAR, the address at which the I keycode is stored. Function 510 then determines whether or not the entry is an alphabetic character key, The manner in which this is accomplished has been discussed above. Assuming it is an alphabetic key, function 520 determines if the ~irst entry flag is set (the ~irst entry flag is a flag maintained in the processor1; this function is accomplished by merely noting the condition of the flag. As will become clear, this flag is set until it becomes reset b~ the keying of a space, other function or most other s~mbol graphics. The use of a hyphen flag, to prevent clearing of the alpha sequence ID register on actuation of carriage return after hypen actuation is illustrated in connection with Fig. lO and is not repeated here. Clearly, the same function and hardwaxe could be used in connection with the embodiment of the invention, not only to pre~ent clearing of the alpha se~uence ID
register, but the first entry register as well. Assuming the first entry flag is not set, function 530 clears the alpha seq~ence ID register and stores the numerical quan-tity associated with a key (shown for example in Table II) in th~ first entry register and also places the identical quantity in the alpha sequence ID register which, as will become clear hereafter, had previously been cleared. Func-t~ 540 then sets the first entry flag. That concludes the processing for this key entxy, which is pertinent to the invention. The remaining processing, in order to ef-fect display of the key character, is not disclosed herein~

1 ~57S67 On the next and each succeeding actuation of a character key, function 520 determines that th~ first entry flag is set and accordingly, functions 530 and 540 are skipped, and in~tead, function 550 is performed.
In the course of operation the operator may actuate a key which is neither an alpha key nor the key which initiates automatic word ending operation, such a key might be, for example, a space bax, caxriage return, etc~
Under those circumstances functions 510 and 560 deter-mine that the actuated key was neither an alpha key nor the automatic word ending key. Accordingly, function 570 merely resets the fixst entry flag.
Assume now that the operator has keyed in every-thing but the word ending, and now desires the word to be automatically completed, The operatox therefore actu-ates the key which initiates automatic word ending oper-ation. Accordingly, function 51Q determines that the actuated key is not an alpha key, but function 56Q deter-mines that the key actuated is the automatic word ending 2n key. Function 580 checks to see if the first entry flag is set. It is noted that if the flag is not set, the processing terminates. Ho~ever, in our example, the first entry flag h~d xemained set and therefore, function 590 is per~ormed to decrement the R~R. Since the R~R pxe-viously addre.ssed the location at which the automatic word ending operation key code was stored, decrementing the RAR
enables it to point to the location immediately preceding the location storing the automatic word operation keycode.
This location stores the keycode of the character initiated immediately priox to word ending operation. Function 600 retrieves this ke~code and function 610 adds a base value K and uses the resulting sum as a pointer into the CPT.
Function 620 obtains the addressed byte from the CPT.
Reference to Figuxe 12 indicates that this byte comprises either a default entry, pointer t~ an alpha table or a pointer to a start address~ Function 630 determines if LE~-7B~Q37 ~ ~ 57~87 the byte corxesponds to a de~aultl If it does, ~unc-tion 640 and 650 are performed to respec-tively reset the first entry flag and signal a default. However, assuming that a default is not located then, as shown in Figure 16B, a base address value (in this case K) is added to the pointer and the results are stored in regis-ter PTRl.
Function 670 determines whether or not the quantity in PTRl corresponds to an alpha table pointer or a start lQ address~ By prearrangement all start addresses are lo-cated in a one memory area, and all alpha tables are stored in a different memory area. Accordingly, simply comparing the calculated address with the lowest address for start addresses, for example, reveals whether a start address or alpha table is addressed. Obviously, other techniques could be employed to determine whether or not the byte extracted from the CPT was an alpha table pointer or a start address. For example, a ~lay could be used to make this determination. In any event, assu~ing that the byte corresponds to a start address, then function 680 loads the staxt address in PTRl and processes the character output string. Reference to Figure 15 illustrates that the character output string is located sequentially begin-ning at the start address, and therefore, as each charac-ter or character pointer is extracted, the quantity PTRlis incremented and the process is repeated until a stop code is detected. When the character string has been output, function 6g0 resets the first entry flag.
Assuming however, that a start address was not im-mediately located from the CPT, then function 700 is per-formed. Function 700 obtains the byte pointed to in the associated alpha table, and compares this byte with the contents of the alpha sequence ID register. Function 710 determines whether or not the comparison indicates ar.
equality. Assuming equality is not indicated, the func-tion 750 incxements PTRl and obtains the next byte in the 1 ~7567 - 5~
alpha table. Function 760 determines lf tne last com-pare flag was set, and assuming it was not, function 770 again increments PTRl. The loop of function 700 through 770 is performed and a comparison made between the con-tents of the alpha se~uence ID register and the corres-ponding byte in th~ alpha table until either comparlson is effected or function 760 indicates that the last com-pare flag is set. Accordingly, the processor proceeds through the alpha ta~le looking for one of these two conditions.
Assuming that at some point in this process the alpha sequence ID value from the alpha table is equal to the contents of the alpha sequence ID register, function 720 is performed to further increment PTRl and address the next byte. Reference to the alpha table indicates that the byte following the alpha se~uence ID value in the alpha table is a pointer, and this incrementing action function 720 obtains that pointer. Since the pointer may point to either an exception table or a start address, function 730 checks the exception flag. Assuming the exception flag is not set, then function 740 uses the byte obtained fxom the alpha table as a pointer and de-velops an address by adding a base value (R~. Note that this base value (R~ is different from previously used value (X-see p. 48~. The tables and addresses employed herein have been adapted for 8 bit words, and most of the alpha table pointers employ only 6 bits, since two bits are set aside for flags. Clearly, if bit capacity was not important, the pointers could all use an identical bit count and therefore the base ~alues could be identical (or dispensed wlth).
In an~ event, functions 80~ and 810 are preformed, which are in all respects similar to unctions 680 and 690 and result in producton of the desired character string.
On the other hand, the processor ma~ proceed entirely through the alpha table up to the next to last . . . . . . .. . .. .. . . . . . . .. .

entry without finding e~uality between the contents of the alpha sequence ID register and the correspondiny alpha sequence value in the alpha table. If this is the case, function 760, at the next to last entry, in-dicates the la~t ~ompare flag is set. Function 780 then increments PTRl and obtains the byte pointed to. As explained in connection with Figuxes 13~ through D, this byte is a start address for a particular word end-ing. Accordingly, functions 800 and 810 are performed to output the character string.
In the event that the exception flag was detected as on, at function 730, then function 820 is performed which employs that byte as a pointer and develop an ad-dress by adding a constant (T~ to the byte, after the flags have been removed. This address is stored in PTRl. As mentioned in connection with Figure~ 13B~D and 14A-B, this byte no~ points to an entry in the exception table. Function 83~ obtains that by~e and function 840 compares the byte to the value in the ~irst entry regis-ter. This byte is the additional data unit employed in 2~ the exception table to make a selection between one of two appropriate word endings, and the selection is made by comparing the byte with the contents of the fixst entry register, which corresponds to the fixst character of the word. Depending on whether or not the comparison is equal, the pointer PTRl i$ eithar incremented by one `~ or by two if the last co~pare flag is set. (Functions .
900 and 88Q~. However, first function 8~0 checks to see if the exception flag is se~. The exception flag~
in connection with the exception table identifies an unresolvable conflict. If the exception flag is set, functions ~lO and ~20 reset the first entr~ flag and indicate the default condition, ~ssuming that the excep-tion flag is not set, then function ~3Q obtains ~he b~te pointed to b~ PTRl, and adds the hase address CK~ to ii.

I.E9-78~037 3 1~7~67 - 5~ ~
If the compa~ison, at function 850 did not indicate equality, and the last compare flag was not set, then instead of incrementing PTRl by one it is incremented by thxee. This allows for more than two ending con~lict groups to be searched for a comparison at function 850.
In any event, once function 930 is performed, the pro~
cessor has, in effect, calculated the appropriate start address and ~herefore, functions ~40 and 950 are per-formed much in the same manner as ~unctions 6ao and 690 to output the desired character string.
1~ In connection with Fiys. 1 and 2 it has been in-dicated that a mode latch set and reset or alternate actuations of the key 38 can be used to assist in de-termining whether automatic word ending is appropriate when a multi-purpose key is used to initiate automatic word ending.
Furthermore, we have indicated that the mode latch can be eliminated and automatic word endin~ operation initiated by the logic alone in dependence on previously actuated characters. Fig. 17A illustrates the processing in connection with the logic of Fig. 7. As is apparent r every actuation of a multi-purpose key is located as an automatic word ending command and the keyls alternate func-tion (typically a numeric character, punctuation graphic or function) is decoded and performed only for the case ~5 of a default in automatic word ending. Fig. 17B illus-trates the processing in connection with the logic of Fig~ 16A-C. To effect a similar result with the logic of Fig. lQ requires some modification to the logic o~
Fig. 10 to ensure that the alpha sequence ID is a legal quantity (one that corresponds to a word ending~ ~efore attempting to output a charactex string.
From the foregoing it should be apparent how auto-matic word ending ope~ation is initiated with or without a mode latch and with single purpose ox multi-purpose keys and how, when automatic ~ord ending is initiated~

LE~=78-037 I ~7~

an appropriate word ending is selected from an ensemble of word endings in dependence on the previously actuated keys.

Claims (28)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An automatic word ending text recorder of the kind having:
text display means to display a sequence of text characters in intelligible form on a page or page-like display in response to character and function identify-ing signals, keyboard means including a plurality of alpha-numeric, symbol and function keys to produce a keycode signal unique to any operator-actuated key, decoding means responsive to keycode signals from said keyboard means to produce said character and func-tion identifying signals, wherein the improvement com-prises:
word ending means within said decoding means pro-ducing one of at least two groups of one or more charac-ter identifying signals in response to actuation of a selected key on said keyboard, each group of character identifying signals representing a different word ending and wherein said word ending means includes means for selecting among said groups depending upon identifica-tion of one or more key actuations prior to actuation of said selected key.

2. The apparatus of Claim 1 wherein said decoding means includes means to store representations of a plura-lity of actuated keys in an ordered sequence in which said keys were actuated by an operator, addressing means rendered operative by actuation of said selected key to address said means to store in re-verse order sequence to thereby read from said means to store one or more keycode signals in said reverse ordered sequence, and decision means responsive to said readout keycode signals to select an appropriate word ending and to pro-duce a representation thereof.

3. The apparatus of Claim 2 wherein said repre-sentation produced by said decision means comprises an address at which is stored a representation of a charac-ter sequence corresponding to said selected appropriate word ending.

4. The apparatus of Claim 3 in which said repre-sentation of said character sequence comprises a se-quence of pointers, each of which points to a stored representation of a different character identifying signal, and a function control storage means pointed to by said sequence of pointers storing a character identify-ing signal for each of said characters in said sequence.

5. The apparatus of Claim 2 in which said decision means comprises:
continue address register means, means responsive to each keycode signal, when pro-duced by said means to store, to sum a keycode repre-senting quantity and the contents of said continue address register means, table means addressed by said continue address register means subsequent to operation of said means to sum to produce said representation of said appropriate word ending.

6. The apparatus of Claim 5 in which said table means includes, a sub-table for each node in a decision tree iden-tifying each appropriate word ending by reference to pre-ceding characters in inverse order of appearance in a word , wherein each entry in said sub-table identifies, a) appropriate word ending, or b) a different sub-table corresponding to a connected node in said decision tree or c) a default condition, and wherein said continue address register means, after operation of said means to sum, addresses a spe-cific entry in a sub-table.

7. The apparatus of Claim 6 in which each entry in each sub-table includes at least a multi-bit control entry identifying the associated entry as, a) an appropriate word ending, or b) a different sub-table corresponding to a con-nected node in said decision tree, or c) a default condition,

8. The apparatus of Claim 7 in which the decision means includes means responsive to a control entry iden-tifying a different sub-table to replace the contents of said continue address register means with at least a por-tion of said entry.

9. The apparatus of Claim 1 wherein:
said word ending means includes sequence accumula-tor means for forming and retaining a sum of quantities, each of said quantities unique to a character key, and means for clearing said sequence accumulator means on actuation of a numerical, function or symbol graphic key, character sequence table means with an entry for each appropriate word ending representing each charac-ter in said word ending, and means responsive to actuation of said selected key to address said character sequence table means with the contents of said sequence accumulator means.

10. The apparatus of Claim 9 which further in-cludes:
a hyphen flag register, means to set said hyphen flag register on detec-tion of actuation of a hyphen key, means to reset said hyphen flag register on de-tection of actuation of an alpha key, and means responsive to actuation of a function key to inhibit clearing of said sequence accumulator means, if said hyphen flag register is set.

11. The apparatus of Claim 1 wherein said word ending means includes:
means to store a representation of each actuated key in an ordered sequence, addressing means responsive to actuation of said selected key to read at least a representation of a preceding key actuation from said means to store, table means addressed by said representation read from said means to store in response to actuation of said selected key to produce a corresponding data unit, some of said data units comprising a representation of said selected word ending.

12. The apparatus of Claim 11 wherein said word ending means further includes:
alpha sequence accumulator means for forming and retaining a sum of quantities, each of said quantities unique to a character key, in response to actuation of keys of said keyboard means, means for clearing said alpha sequence accumulator means on actuation of any key within a selected sub-set of non-alpha keys, and means for combining said data units with con-tents of said alpha sequence accumulator means on actu-ation of said selected key to produce modified data units, first comparing means for comparing a data unit from said table with a first reference to detect a de-fault condition, and second comparing means for comparing a modified data unit with a second reference and to identify a selected word ending from said modified data unit if said comparison is favorable.

13. The apparatus of Claim 12 wherein said word ending means further includes:
alpha table means addressed by said modified data unit for storing and reading out, when addressed, a second data unit, second comparing means for comparing contents of said alpha sequence accumulator means with said second data unit, means fox incrementing said alpha table to obtain a third data unit, test means to test for one or another test on said third data unit depending on the outcome of said second comparison, means for extracting a representation of said se-lected word ending from said third data unit if said comparison is favorable and said one test is passed, a first entry register, means to store in said first entry register a representation of a first charac-ter of a word and means to clear said first entry regis-ter on actuation of a selected sub-set of keys of said keyboard means.

14. The apparatus of Claim 13 which further in-cludes exception table means, means to address said exception table means with said third data unit, if said comparison is favorable and said one test is not passed, third comparison means for comparing a fourth data unit from said exception table means with contents of said first entry register, and means, responsive to a favorable result of said third comparison for extracting, from said exception table means, a representation of said selected word end-ing.

15. The apparatus of Claim 13 which further in-cludes means for further incrementing said alpha table means, if said second comparison is unfavorable and said another test is passed, and extracting a represen-tation of said selected word ending.

16. The apparatus of Claim 13 which further in-cludes means for further incrementing said alpha table means, if said second comparison is unfavorable and said another test is not passed and for extracting another data unit for said second comparison means.

17. The apparatus of Claim 12 wherein said word ending means further includes:
alpha table means addressed by said modified data unit for storing and reading out, when addressed a sec-ond data unit, second comparing means for comparing contents of said alpha sequence accumulator means with said second data unit, means for extracting a representation of said selected word ending from a third data unit read from said alpha table means if said second comparison is favorable, and means for incrementing through said alpha table means if said comparison is unfavorable.

18. The apparatus of Claim 17 wherein said alpha table means includes at least two entries, a first entry including said second data unit and said third data unit and at least one entry including said third data unit but omitting said second data unit.

19. The apparatus of Claim 18 in which said alpha table means includes, in an entry preceding said at least one entry, a last compare flag set to a distinctive con-dition and which further includes, means responsive to said set last compare flag to extract said third data unit of said at least one entry as a representation of said character identifying sig-nals.

20. The apparatus of Claim 1 wherein said word ending means includes first means responsive to actuation of a function key, subsequent to actuation of said selected key, to clear a register, a hyphen flag register, means to set said hyphen flag register on detec-tion of actuation of a hyphen key, means to reset said hyphen flag register on detec-tion of an alpha key, means responsive to detection of a function key to inhibit operation of said first means.

21. The apparatus of Claim 1 in which said word ending means operates on each actuation of said selected key.

22. The apparatus of Claim 1 Which further includes, mode changing key means for changing an operating mode of said text recorder from an automatic word ending mode to a non-automatic word ending mode and in which said selected key selectively actuates said word ending means only when said text recorder is in an automatic word ending mode.

23. The apparatus of Claim 1 which further includes, means responsive to actuation of said selected key for selectively producing a group of character identifying signals or producing a different character/function identifying signal and further including default means in said word ending means for signaling a default condition if an appropriate word ending cannot be selected and means responsive to said default means for initiating said different character/function identifying signals.

24. A method of operating text recorder such as an electronic typewriter to provide appropriate word endings, on command, which text recorder includes keyboard means with plural alpha, numeric function and symbol graphic keys, text display means for displaying a sequence of text characters in intelligible form, and decoding means responsive to operation of said keyboard means for driving said text display means in which the method comprises the steps of:
storing a character preceding table representing a matrix of appropriate word endings as a function of the character preceding a word ending, if said preceding character uniquely identifies an appropriate word ending, and addressing said character preceding table with a representation of a character preceding actuation of an automatic word ending initiation key actuation to identify an appropriate word ending, and employing said identification to output a word end-ing character string to said text display means.

25. The method of Claim 24 in which said text re-corder includes an alpha sequence register which sums a unique quantity for each alpha key actuation with the contents of said alpha sequence register and which in-cludes means to clear said alpha sequence register on actuation of selected non-alpha keys, and wherein said method includes the further steps of:
storing a separate alpha table for each character preceding a word ending t which character does not uniquely identify a word ending, each alpha table comprising an entry for each word ending preceded by the character associated with the word ending, said entry including either a pointer to an appro-priate word ending and an ID sequence number, if said ID
sequence number uniquely identifies said word ending, or a pointer to an exception table pointer, a flag and an ID sequence number if said ID sequence number does not uniquely identify an appropriate word ending, storing in said CPT table a pointer to an associated alpha table, incrementing through said alpha table until the con-tents of said alpha sequence register matches the ID se-quence number, and extracting said word ending pointer if no flag is found or extracting said exception table pointer if said flag is found.

26. The method of Claim 25 in which said alpha table includes a last entry flag, said incrementing step is performed only once after said last entry flag is found and said extracting step is performed with said incremented address.

27. The method of Claim 25 in which said text re-corder includes, an entry register which stores a quantity represen-tative of a selected character in a word and is cleared on actuation of selected non-alpha keys, and in which the method includes the further steps of:
storing an exception table comprising an entry for each conflict where an alpha sequence register content cor-responds to more than a single word ending, each said ending related to said entry, and a data unit uniquely related to a character in one word associated with one but not the other word ending, comparing a data unit in an exception table entry with the contents of said entry register and selecting one of the other of said different pointers depending on said comparisons.

28. The method of Claim 27 wherein said entry register and said data unit stores a data unit corres-ponding to the first letter of a word.