Automatically adjustable delay function for timed typamatic
Contents
1. keyboard processor controls and receives signals from the keyboard and provides those signals to a main pro cessor which in turn provides signals to the keyboard processor to the printer and receives feedback signals from the printer FIG 2 is a flow diagram illustrating the flow of oper ations for carrying out the automated adjustment of the delay time for a timed typamatic keyboard FIG 3 is a flow diagram illustrating the flow within the timer interrupt routine DESCRIPTION OF THE INVENTION For purposes of implementation and for purposes of describing this invention a microprocessor sold under the designation Intel 8048 microprocessor sold by the Intel Corporation of Santa Clara Calif is used as the control of the electronic keyboard 12 Hereafter the Intel 8048 microprocessor will be referred as the key board processor 16 The Intel 8048 microprocessor is readily commer cially available and the Intel Corporation provides man uals on its use indicating available register designations available flags and their designations and a list of in struction codes which may be utilized to cause the pro cessor to function Additionally the Intel 8048 has eight bit timer which counts in response to clock pulses generated by the timing clock of the microprocessor 16 and will run through a complete 256 count timing sequence and overflow every 20 48 milliseconds Msec The Intel 8048 processor in addition to bei2. portion of the processor 16 continues to operate simul taneous with other functions of the processor 16 per forming the flow illustrated in FIG 2 Every time the timer of the processor 16 reaches a condition where all bits are 1 that is indicated as an overflow condition and a timer interrupt signal emits from that portion of the processor 16 to interrupt the sequence of operations in the flow of FIG 2 As dictated by the construction the Intel 8048 processor utilized as the keyboard pro cessor 16 any time there is a timer overflow condition initiating a timer interrupt command the processor 16 immediately goes to address 07 which is jump to count routine instruction This is illustrated block 202 From the jump to count instruction stored in address 07 block 202 the count routine is entered to effect the counting in register R2 for keeping track of the time delay Upon the receipt of a timer interrupt command and the processing of the jump to count instruction block 202 the timer overflow count register R2 1s decremented by one and a check to see if the timer overflow count is now zero block 204 If the overflow counter contents is not zero then the flow follows the NO path from block 206 where that decision is made to block 208 where a routine directs that zeros are loaded into the timer As soon as the zeros are loaded into the timer as commanded by subroutine indicated at block 208
3. 4 490 055 1 AUTOMATICALLY ADJUSTABLE DELAY FUNCTION FOR TIMED TYPAMATIC BACKGROUND OF THE INVENTION With the advent of electronic keyboards on terminals and typewriters there has been a need for improving the operation of those keyboards to accomplish repeat characters On mechanical keyboards which have the typamatic or repeat character capability by holding the keybutton depressed to a second force level the ma chine will repeatedly cycle and print repetitively the character indicated by the keybutton However with keyboards using electrical or elec tronic contacts or a change in capacitance to indicate the depression of a keybutton for character selection it is preferable to utilize an alternate technique of selecting repeated characters from the second depression force level approach With electronic keyboards whether they be capaci tance or switch arrangements all the positions on the keyboard are scanned or sequentially queried to deter mine whether a keybutton has been depressed to select the character One technique for repeating a character is the depression and release and redepression of the desired key This approach will produce a plurality of identically repeated characters For keyboards having the repeat character character istic the keybutton may be held depressed and the pro cessor which controls the scanning and other organiza tional functions of the keyboard will detect the held down condition an
4. Call Typamatic Call Interrogate Mov A R7 JBI P3 Jmp P1 JB9 P4 Jmp P5 Call check CPL F Jmp P6 JB2 P7 JB9 P8 Jmp P6 Jump if Typamatic Flag is Set Get Index or Register Check for key transition No transition go to beginning Jump if in typamatic mode Reset typamatic flag Jump to Process key transition Jump if key depressed Jump if key is typamatic Jump to Process key Transition 4490055 11 E 12 APPENDIX A continued j sU APPENDIX A continued LO PRO uf LO lt lt PRO CA GRAM 1 ERES CA GRAM eee TION CODE BEL COMMENTS os CODE BEL NMEMONICS COMMENTS 3C 14 P8 Call stop timer 2 2 AR UE uS Y 3D 89 See TA 3E 94 Jmp P6 Jump to 75 ets 76 Transition 77 52 E SW 1 0 2278 40 12 P7 Jmp P9 Jumpifkey 499 E is typamatio TA Start Mov A R4 Move whole 41 4A 5 um PU Timer value to R2 42 94 JF1 P10 Jump if timer JB UAA Mov R2 A e 2 running 2 pit IDYC FD Mov A R5 Move fractional 3 value 44 04 Imp 6 Jump to Sed S VC IB Mov R3 A 7E 62 Mov T A Load fractional Transitions value inte 45 52 SU timer 5 timer TE 55 Start T Start timer 48 4 Jump P6 Jump to 20 5 Hs ee Fi Set timer Process key 82 Transitions
5. be electronic in nature If an electronic keyboard is implemented on a typewriter or for that matter an electronic data processing terminal the key board is controlled by a processor which accepts signals from the keyboard responsive to a scan routine The scanning of the keyboard is a technique for sequentially addressing each of keybutton positions and determining whether a circuit is complete through that keybutton position to indicate the operator having depressed the keybutton In addition to the scanning or sequential interrogation of each key position to determine a change in the state of the switching device utilized the keyboard processor is capable of performing timing functions The keyboard processor can time the period that a particular selected keybutton or a group of key buttons are held depressed For example a single keybutton such as the space bar may be timed for each depression of the space bar or the keybuttons which are designated as typamatic or repeat character keys may be timed whenever any one of them is held depressed If a typamatic key is held depressed for a period which is within 100 milliseconds of the preselected delay time the keyboard processor auto matically resets the delay time value to a next higher delay time unless the delay time is already at the maxi mum preselected value If the keybutton is still depressed and the switching element in the keyboard indicates that the circuit is made for that
6. cycle is the portion of the timer cycle not required and thus represents a starting point for the timer to count upwardly from To determine the fractional amount to be loaded into the timer the equa tion 20 48 0 76 20 48 0 08 61 is illustrative of how the fractional value for a 200 millisecond time delay is determined The 20 48 is representative of the time required for a complete timer cycle and 0 76 represents the fractional portion of a timer cycle required in addi tion to the complete timer cycle for the desired time delay Similar calculations may be performed to arrive at the whole or fractional number values for the registers R20 and R29 for each of the predetermined time delays For each of the predetermined time delays two regis ters have been dedicated to storing the numbers and thus they are available to the processor 16 to update the time delay when appropriate Again referring to FIG 2 after the initialization procedure and the initializing of the typamatic flag F0 and timer flag F1 to an unset condition the sequence of events portrayed by the flow diagram may proceed It should be noted that flag FO and F1 are arbitrary flags which may be used and their use is available to tlie designer for any purpose desired and may be set and reset as desired under instruction control These flags F0 F1 are provided in the Intel 8048 used as the key board processor 16 10 5 25 30 65 6 After t
7. delay period being considered is applicable only to the most recent typamatic key 19 21 and effectively removes the possibility of inadvertently typing repeat characters from a former typamatic key 19 21 when it is clear by the depression of a subsequent key that the operator does not desire to enter the typamatic mode on the earlier key depression Returning to decision block 114 if the determination is that the key transition was a depression and that it was not a typamatic key 19 21 then if the timer flag F1 is set and thus the timer is running the timer is stopped as indicated in block 120 This insures that any previous 4 490 055 7 typamatic key 19 21 which remains depressed does not trigger subsequent repeat characters Upon the completion of either the restarting of the timer in block 118 or the stopping of the timer in block 120 the key transition is processed and an output is generated to the typewriter printer processor 18 to accomplish printing of the selected character in accor dance with the other keyboard routines and the flow returns from the key transition processing block 122 back to enter block 104 for the next cycle Referring back now to decision block 112 where the determination was made as to whether a key transition with no typamatic flag FO set was a depression or a release and where the decision was that the transition was a release the determination is then made as to whether the key 17 19 21
8. pp 4759 4760 IBM Technical Disclosure Bulletin Multiple Repeat Rates for a Terminal Keyboard Leimer vol 23 No 2 Jul 1980 p 770 Technical Disclosure Bulletin I O Keyboard Switching of Keys from a Typamatic to a Non Typa matic Status Motola vol 24 No 11B Apr 1982 p 5859 MCS 48 Microcomputer Users Manual published 1978 by Intel Corporation pp 1 1 2 15 Primary Examiner Ernest T Wright Jr Attorney Agent or Firm Laurence R Letson 57 ABSTRACT A typewriter is described which has an electronic key board utilizing a timed delay to determine whether a depressed key is indicative of the desire to print or display repetitive letters represented by that key The typewriter is provided with a technique for automati cally adjusting the length of the delay such that a slow typist with sluggish finger movement will automatically cause the extension of the delay time and thereby pre vent unwanted repetitive characters while a fast very rhythmic typist will not cause the automatic extension of the delay time and thereby will benefit from a shorter delay time and will have a higher output or productiv ity as a result thereof The automatic extension is accomplished by timing the period of time that keylevers are held depressed and when that time approaches but does not exceed the preset automatic delay time the delay time is then ex tended a predetermined amount 11 Claims 3 Drawing Figur
9. the timer will immediately begin 2 5 counting in response to the timing pulses of the key D board processor clock Thereupon the flow goes to return block 210 Upon entering the return routine block 210 the processor 16 E 5 returns to the flow in FIG 2 at precisely the point it was when the interrupt command was issued by the timer The flow of FIG 2 then continues uninterrupted until such time as a subsequent timer interrupt command issues upon a timer overflow condition Referring back to block 206 if the overflow counter contains a zero after the decrementing in block 204 the YES path is followed and the current address of the key position which has been held depressed throughout the entire period of time that the timer was overflowing a sufficient number of times to decrement the timer over flow counter to zero is stored block 212 This address will be utilized by main flow in FIG 2 specifically block 130 during a check routine to determine subse quently when that typamatic key 19 21 is released After the storage of the typamatic key address block 212 the typamatic flag FO is then set block 214 and the counter is stopped This effectively prevents timer from continuing to time inasmuch as there is no need to do so until either the typamatic key 19 21 has been released or another typamatic key 19 21 has been depressed This operation is represented by block 216 At the s
10. when said period is within a predetermined amount of time of said prolonged period thereby automatically sens ing a sluggish typist and increasing the prolonged period a key must be held depressed to cause repet itive character or function selection 6 The apparatus of claim 5 wherein said means for increasing comprises a timer overflow counter and means for selecting predetermined values for use in said timer overflow counter 7 The apparatus of claim 5 wherein said means for timing comprises a timer counter of fixed capacity which overflows when counted to capacity and said means for comparing comprises a timer overflow counter for accounting for timer overflow events 8 The apparatus of claim 5 wherein said means for timing is operatively associated with selected keys on said keyboard 9 The apparatus of claim 8 wherein said selected keys comprise a space key and a period key 10 The apparatus of claim 5 wherein said apparatus having said keyboard is a typewriter 11 The apparatus of claim 5 wherein said repetitive character selection comprises repetitive printing of said character
11. which will also accommodate a slow or sluggish keystroke This adjustment will occur very rapidly after the typewriter 10 is turned on and typing commences inasmuch as the spacebar 21 and period key 19 are both typically typamatic keys with a relatively high degree of usage Thus a slow typist who tends to linger on the keybutton will of necessity condition the typewriter 10 within a very very few keystrokes on either of these keys 19 21 to extend the delay time A typist with a fast and very rhythmic stroke will not adjust the time delay as rapidly and therefore will be able to avail the typist of a shorter delay time for any intentional typamatic characters APPENDIX A LO PRO CA GRAM TION CODE BEL NMEMONICS COMMENTS Dun gt 0 5 20 35 cA 0 tA uA 65 LO CA TION 7 SmI ow P ow 12 13 14 15 2E 2F 31 32 33 34 35 36 37 38 39 3A 3B GRAM LA CODE BEL 94 9A 10 APPENDIX A continued PRO NMEMONICS Jmp Count COMMENTS Timer Interrupt Pointer Following is part of an initialization routine 2D 4 20 12 94 52 52 ac 94 52 ENI CLR F CLR Fl Mov H29 Call load delay Enable Timer Interrupt Reset Typamatic Flag Reset Timer Flag Initialize Pointer Places current delay value in R4 and R5 Other keyboard routines located here P3 P4 P JFOP Jmp P2
12. 49 52 83 4A 04 Jmp Jump if timer 84 running 85 4B 4E 25 86 4C 94 Imp P12 72287 4D 50 88 4E 14 Pl Call stop timer 89 65 Stop Stop tent Stop timer 4F 89 8A BS timer Cpl Fl Reset timer 50 14 PI2 start timer flag 51 7A 30 8B FA Mov R2 Check if 52 14 P6 Call Process remaining Key Transition timeless propi MUS 53 than 100 msec 54 4 Jmp Jump to 8C 37 CpLA me tig beginning 8D 93 Add A H 5 55 20 8E 5 CL ed wes 56 35 gr F6 JC increase Jump 57 delay 277 remaining 58 timeless than 59 i 100 msec j 5A 99 6A 4 5B 91 83 RET 5 40 92 5D 93 3E 94 SE 95 69 F Load Mov A R Gets delay 96 Delay 3 values using 97 3 pointer 45 9 pi er 1 61 Mov R4 A i va Be 62 18 INC R 9B AS 2 63 Mov A R 9 AT Re f 64 AD Mov R5 A eu eserved for 65 83 Ret 50 9D code to store 66 IE s current key 67 teg address 68 gp 69 8 77795 Cpl F Sets typamatic 6A FC In Mov R4 If stop ed flag crease timer routine 55 65 Stop tent Stop timer diy indicates that a A2 B5 Cpl F1 Reset timer new delay value Ts flag is needed this 94 Jmp Count 2 routine will 5 5 00 0 5 4 AP Zu increment R av dd 27 Count A Load zeros pointerand 60 LEE into timer load delay Di SAGES 62 Mov T A 6B D3 XRLA H29 EG TAT 93 Co
13. It checks the printer feedback signals to determine when the printer is ready for the next character The sequential interrogation block 106 is a routine which is dictated by the type of keyboard used such as conductive capacitive or membrane In conjunction with the interrogation controls a register is used to store indicators of status in bits 0 1 and 2 and are designated Bit 0 typamatic bit 1 typamatic not typamatic Bit 1 key transition bit 1 transition no transition Bit 2 key depressed released 1 depressed 0 released The interrogation routine determines 1 if the key position is typamatic and sets bit 2 if the key 17 19 21 is up or down 3 if key transition has occurred and sets bit 1 and 4 if the key 17 19 21 has been released or depressed bit 2 The processing of the key transition block 122 controls output of data to the printer type writer processor 18 and controls the scanning of the keyboard 12 Specific examples of these routines will not aid in understanding the invention and are not part thereof By adjusting the time delay through which an opera tor must hold a typamatic key 19 21 depressed in order to get repetitive character printing the slow typist will automatically with a minimum of errors cause the ad justment of the time delay typically within three or four typamatic key cycles to a value which will insure that the typamatic characters are only printed when desired and
14. United States Patent Johnson et al n1 Patent Number 43 Date of Patent 4 490 055 Dec 25 1984 54 AUTOMATICALLY ADJUSTABLE DELAY FUNCTION FOR TIMED TYPAMATIC Carl F Johnson James M Williams both of Lexington Ky 75 Inventors International Business Machines Corporation Armonk N Y 21 Appl No 393 928 73 Assignee 22 Filed Jun 30 1982 51 Int i P B41J 5 28 352 UIS CE 400 51 400 704 340 365 E 58 Field of Search 400 50 51 52 321 400 368 369 704 70 340 365 E 365 S 56 References Cited U S PATENT DOCUMENTS 2 717 688 9 1955 Brooks sss 400 704 3 270 438 9 1966 Ephraim 400 704 X 3 436 735 4 1969 Hoiseth 400 368 X 3 618 034 11 1971 Hecker 2 400 51 X 3 643 773 2 1972 Holmes Jr 400 50 X 3 781 874 12 1973 Jennings 400 51 X 3 973 662 8 1976 Fulton 400 50 X 4 106 011 8 1978 Melanson et al 340 365 E 4 189 246 2 1980 Kane et al 400 51 X 4 263 582 4 1981 Dumbovic 340 365 S 4 323 888 4 1982 isses 400 368 X FOREIGN PATENT DOCUMENTS 1411549 10 1975 United Kingdom 400 51 OTHER PUBLICATIONS IBM Technical Disclosure Bulletin Variable Time Delay for Hammer Firing in Rotating Disk Type Printer Balcezak et al vol 21 No 12 May 1979
15. ame time the timer flag F1 is reset to a zero condition indicating that the timer is not functioning At this point the flow goes to return block 210 wherein gt the main flow of FIG 2 is reentered at the precise point that the timer interrupt occurred and the process illus trated by the flow diagram in FIG 2 continues uninter rupted until interrupted by another interrupt command lt gt lt The rectangular blocks in the above routine represent subroutines which are performed under a series of in structions contained in the read only storage portion processor 16 The sequential interrogation of each key 4 490 055 9 position in block 106 the other keyboard routines in block 102 and the processing of the key transition 122 have not been listed in Appendix A inasmuch as they are conventional routines which can be found in elec tronic keyboards presently on the market for example in the IBM 6240 keyboad manufactured and sold by the International Business Machines Corporation Armonk N Y The routines enumerated in Appendix A involve some aspect or significantly add to the understanding of the invention herein and therefore are included Appendix A has a code listing of instructions set forth using conventional notation and is grasped into five columns Location Program Code Label Nmemonics and Comments The routine in block 134 is the routine which controls the output of characters in the repeat mode
16. d repeat the character automatically This approach although having many advantages re quires a timed delay after the depression of the keybut ton before a second and subsequent cycles are initiated to insure that the typist has had an opportunity to re move the finger from the button and thereby not inad vertently initiate detection of the made or depressed condition indicating repetitive characters This may be accomplished by requiring a timed delay of 500 or 600 milliseconds from the time that the first keybutton clos ing is sensed If after the predetermined delay time the key is determined to be still held in a depressed condi tion the processor assumes that repetitive characters are to be printed and initiates the appropriate printing cycles to form those characters on the record media typically at machine cycle speed and continuing until such time as the keybutton is released and the keyboard processor detects the change of condition from a de pressed key to a released key Typewriters and data processing terminals utilizing electronic keyboards and which are presently in the market utilize a fixed time delay typically 600 millisec onds This 600 millisecond delay is too long a period for a fast typist since a fast typist can typically key charac ters at an average rate of one character every 200 milli seconds or less The net result of the 600 millisecond delay period is that a fast typist has their typing rhythm interrupt
17. ed by virtue of having to stop and wait an additional 300 400 milliseconds for the repeat mode to begin to be initiated A shorter time delay is undesirable from the stand point that a slow or sluggish typist will allow the fingers to rest on the keyboard keys and may inadvertently leave the key depressed for such a period of time as is necessary to initiate the repetitive printing or typamatic printing of a character 5 0 20 40 45 50 60 2 Inasmuch as the operator or typist is unique in their timing rhythm speed and the length of time that a key is held depressed it is not possible to provide a single timed delay which is acceptable or optimal for a great majority of the operators OBJECTS OF THE INVENTION It is an object of this invention to adjust the delay and to lengthen the delay between the time a typamatic key is sensed as being depressed and the time that repetitive cycles are initiated under machine control It is another object of this invention to reduce errone ous typewriter inputs by sensing the typamatic keys and sensing the speed by which the keys are released and based thereon adjusting the delay period It is still another object of the invention to increase typing accuracy on timed typamatic keyboards for slower typists by providing a longer period within which they may react to release a keybutton SUMMARY OF THE INVENTION Electronic typewriters typically have keyboards which may
18. een set and where the flag F0 has been set the decisional flow will be to decision block 130 where a determination is made as to whether the current typamatic key 19 21 has been released In the event that the current typamatic key 19 21 has not been released the flow returns to reenter block 104 In the event that the current typamatic key 19 21 has been released block 130 then the typamatic flag FO is reset by the subroutine represented by block 132 and then the key transition is processed by block 122 In decision block 130 there is a check procedure performed to determine whether the current typamatic key 19 21 has been released This check compares the last key transition address or the key location designa tion on the keyboard 12 which last indicated a key transition with the current typamatic key address to determine if the current typamatic key 19 21 was the one released If the transition indicated as a release is not the current typamatic key 19 21 then there is con tinued scanning of the keyboard 12 by reentering at a point upstream from block 104 When the current typa matic key is released Block 130 and there is a compare between the last key transition address and the current 10 20 25 35 45 55 65 8 typamatic key address then the flow follows the YES path to block 132 Referring to FIG 3 the flow of the timer interrupt routine is illustrated For best understanding the timer gt
19. es 2240 20341 1 ROUTINE DEPRESSED SEPPESSED OB mean i m 1 SEQUENTIAL INTERROGATION OF EACH REY POSITION 1 cher TER FLAG AP TIMER 5 RUNNING i TIMER i i i mi 4 CHECK TIMER FLAG F1 i MER IF TIMER S RUNNING sem 128 i STOP TIMER CURRENT TYPAMATIC KEY RELEASED 1 RESET TYPAMATIC i FLAG FO QUTPUT 10 TYPEWRITER TERMINAL PROCESSOR 4 490 055 Sheet 1 of 3 U S Patent Dec 25 1984 FIG 4 PROCESSOR a lt x 8 gt lu TYPEWRITER PRINTER PROCESSOR U S Patent Dec 25 1984 Sheet 2of3 4 490 055 FIG 2 INITIALIZATION ROUTINE 430 CURRENT TYPAMATIC DEPRESSED KEY RELEASED RELEASED RESET TYPAMATIC FLAG FO CHECK TIMER FLAG FI IF TIMER IS RUNNING STOP TIMER CHECK TIMER FLAG F1 IF TIMER 15 RUNNING STOP TIMER CHECK ELAPSED DELAY TIME CHANGE DELAY VALUE IF NEEDED QUTPUT TO TYPEWRITER TERMINAL PROCESSOR U S Patent Dec 25 1984 Sheet 3of 3 4 490 055 FIG 3 TIMER INTERRUPT 202 ADD 01 JUMP TO COUNT ROUTINE DECREMENT TIMER OVERFLOW COUNTER 204 CHECK FOR ZERO NO LOAD ZEROS INTO TIMER 206 YES IS OVERFLOW COUNTER ZERO 208 22 STORE CURRENT ADDRESS 244 SET TYPAMATIC FLAG FO 246 STOP COUNTER RESET TIMER FLAG FI is 210 RETURN
20. he initialization routine is accomplished block 100 other keyboard routines not germaine to this in vention are performed by the keyboard microprocessor 16 block 102 and by way of illustration include the checking of the code key 13 on a typewriter keyboard 12 to determine whether it has been depressed signaling a command other than a character selection when com bined with a character key depression Additionally a check of the printer feedback signal from the printer processor 18 may be made at this time to maintain the keyboard processor 16 in synchronization with the printer processor 18 and the printer assembly 14 The flow then proceeds to block 104 wherein a deci sion is made as to whether the typamatic flag FO is set Initially the typamatic flag FO has been initialized in the initialization routine in block 100 in an unset condition and therefore the flow proceeds through the path to the sequential interrogation of key position sub routine in block 106 In electronic keyboards the key board processor 16 sequentially addresses the matrix of keyboard switching elements 11 to determine which if any have been caused to create a transition from a make to a break or from a break to a make condition As a result of this sequential interrogation the flow proceeds to block 108 wherein a decision is made as to whether a key transition from a break to a make or make to a break has occurred in the keyboard 12 If no trans
21. ition has occurred then the flow returns by the path indicated and reenters the decision block 104 to determine whether the typamatic flag has been set This loop con tinues until such time as a key transition has been de tected and such a decision has been made that a transi tion occurred in decision block 108 Upon the detecting of a key transition the flow pro ceeds from block 108 to block 110 wherein the typa matic question is posed Has the typamatic flag been set If the typamatic flag FO has not been set the pro cessor flow proceeds through the no path to decision block 112 which determines whether the key transition determined in block 108 was a depression or a release If the transition was a depression of the key then the path goes to the decision block 114 where the determination is made as to whether the key which ransitioned was a typamatic key such as a period 19 or space 21 key and if the key was a typamatic key 19 21 then the flow path goes by the yes route to check the timer flag F1 and if the timer is running to stop the timer as indicated in subroutine block 116 This condition is a condition which may exist if the typamatic key 19 21 just de pressed was the second consecutive typamatic key 19 21 f Upon the completion of stopping the timer it will have the effect of initializing the timer and the timer is then restarted in block 118 By stopping the timer and restarting the timer this insures that the time
22. m the printing assembly 14 to main tain control of the printing assembly 14 in an appropri ate sequence Printer processor 18 receives character signals and other necessary control signals from the keyboard processor 16 and provides feedback to ia board processor 16 The keyboard processor 16 likewise has two way connections to the keyboard 12 to provide signals to the keyboard 12 for purposes of scanning the keyboard 12 and a return path for signals from the 2 button switching elements 11 in keyboard 12 such that the signals generated thereby may be transmitted to the keyboard processor 16 Referring to FIG 2 the initialization routine in block 100 accomplishes the loading of preset information into designated registers RO R3 R7 within the processor 16 when the processor 16 and typewriter 10 are initially turned on This information is permanently stored in non volatile read only memory locations within the keyboard processor 16 and is not changeable type of information The information loaded into the respective registers with their initial values are set forth below by way of illustration and not by way of limitation Description of or Information Contained Register Designation in the Register RO Pointer to cause the addressing of selected registers R20 R29 R2 Timer overflow count R3 Fractional delay value R4 Whole portion current delay value R5 Fractional porti
23. ng readily available in the marketplace is a conventional piece of electronic equipment widely used in many applications The architecture and operation of the Intel 8048 pro cessor is described in the MCS 48 Microcomputer User s Manual Copyright 1978 Intel Corporation pages 1 1 through 2 16 which are incorporated herein by reference The Intel 8048 processor includes within its structure at least a clock timer event counter registers memory locations read only memory flags FO and F1 These elements of the Intel 8048 processor are utilized to control the monitoring and altering of the timed delay of the typamatic function as it is more completely described below Appendix A attached is a listing of instructions state ments and instruction codes and addresses which will control the keyboard processor 16 to perform the rou tines described in the flow diagram of FIG 2 While this system is described in connection with a typewriter 10 and utilizes the input from the typewriter keyboard 12 it should be recognized that this same typamatic adjustment of the delay may be implemented on any system which utilizes an electronic keyboard and which has typamatic keys and where the processor responds to a timed delay period after the first detection 5 20 25 40 45 50 35 65 4 of the depression of a selected typamatic key to initiate subsequent printing cycles Printing cycle is used in the con
24. on current delay value R7 Status Register R20 9 R21 61 R22 14 R23 90 4 490 055 5 continued Description of or Information Contained Register Designation in the Register R24 19 R25 120 R26 24 R27 151 R28 29 R29 180 With the initializing of the registers RO R29 as indi cated herein the timing delays are stored such that they are accessible by the processor 16 not in terms of actual time delay but rather in terms of complete timer cycles which require 20 48 Msec per timer cycle The tabula tion below indicates a time period delay and the number of whole timer cycles and a value which when loaded into the timer will result in a fractional timer cycle very closely approximating the desired time and which cor relate to the initialization values of registers R20 R29 above Whole Cycles Fractional Cycle 200 Msec 9 11 61 300 Msec 14 90 400 Msec 19 120 500 24 151 600 Msec 29 180 The timer is a 256 cycle or an eight bit timer which operates on the 80 microsecond clock pulse period thus resulting in a complete timer cycle from 0 to 256 in 20 48 milliseconds Thus to get a 200 millisecond delay will require a total of nine complete timer cycles and 0 76 fractional timer cycle In order to operate the timer within its operational constraints an initial fractional value is loaded into the timer from which the timer will then count upward to its capacity of 256 Thus a value loaded into the timer
25. particular keybutton at the end of the timed delay period and that keybutton represents a typamatic character the keyboard processor detects this condition and begins to repetitively output the character signal to the main typewriter or printer pro cessor to cause the printing of that character at the printer machine rate Further the adjustment of the delay time is supressed inasmuch as it is clear at the end of the delay period that the reason for continued depression of the key was to cause typamatic printing Release of the typamatic key prior to the end of the delay period will prevent any repeating characters Additionally the depression of any other key on the keyboard will be detected notwithstanding the contin ued depression of the typamatic key and the depression of this other key during the time delay period will indi cate a desire to subsequently print a second character 4 490 055 3 and not enter the repeat mode and therefore will defeat the entry into the repeat mode notwithstanding the continued depression of the typamatic key If the typamatic mode of operation is entered after the time delay period there will be no change in the delay time inasmuch as the long period of depression of a typamatic key is due to the desire for repetitive typing rather than due to sluggish typist action or slow re moval of the finger from a typamatic key DRAWING FIG 1 illustrates a generalized system wherein a 10
26. released was a typamatic key in decision block 124 The purpose of this is to accom modate the stopping of the timer upon the release of the key Block 126 If the key 17 19 21 was a typamatic key then the stop timer routine block 126 is the next function of the processor 16 and the time elapsed determined in block 128 If the time elapsed is within approximately 100 milliseconds of the current delay time then the subrou tine represented by block 128 will change the delay value to the next larger predetermined delay value as represented in registers R22 R29 The check of the time is effectively accomplished by checking the value in register R2 and comparing it with a preset numerical value of 5 If it is equal to or less than 5 the typamatic 19 21 key has been held down to within approximately 100 milliseconds of the current delay time and the sub routine will make the desired change in the delay time value After the completion of making such a change the key transition is processed and in this case would not initiate a character The key transition processing is accomplished in block 122 Referring back to the decision in block 124 as to whether the released key 17 19 21 was a typamatic key and with a NO response to that determination then the next step is the processing of key transition 122 Returning to decision block 110 wherein a determina tion is made upon a key transition as to whether the typamatic flag F0 has b
27. rmining the period of time a key on said keyboard is depressed determining if said period of time is less than but within a predetermined amount of said predeter mined time period and if within said predeter mined amount adjusting said predetermined time period to a longer predetermined time period thereby lengthening the time period a key must be held depressed to initiate repetitive character display or function operation when a key is held depressed a period approaching said predetermined time period but 20 25 30 35 40 45 50 55 65 14 insufficiently long to cause said repetitive charac ter display or function operation 4 The method of claim 3 wherein said adjusting com prises providing a plurality of selected time periods and selecting the next larger of said time periods and substituting said next larger of said time periods for said first predetermined time period 5 A character displaying apparatus having a key board capable of at least some repetitive character and function selection through key depression for a pro longed period of time comprising means for detecting key depression and release means for timing the period between key depression and key release means for comparing said period with said prolonged period means for initiating repetitive character or function selection when said period exceeds said prolonged period and means for increasing said prolonged period
28. unt 6 29 pe sii gt 6D C6 JZ Delay 1 unii u 6E 72 eee 6F 18 INC R pte P 79 14 Call load delay LEN ET 71 6 72 83 Delay RET 4 490 055 13 APPENDIX A continued LO PRO CA GRAM LA TION CODE BEL NMEMONICS COMMENTS AF We claim 1 method of controlling the sensing time period for detecting a condition indicative of a desire for a charac ter to be repetitively displayed comprising providing a preset sensing time period the exceeding of which by the depression of a single character key is indicative of a repetitive display operation measuring the period of time that a selected control key is depressed comparing said period of time with a predetermined standard time period increasing said sensing time period when said period of time exceeds said standard time period whereby an operator who is slow and holds keys depressed for a longer period of time than normal will not undesirably display multiple characters 2 method of claim 1 wherein increasing said sensing time period comprises selecting one of a plural ity of varying sized sensing time periods 3 The method of controllably changing the time period a key of a keyboard must be maintained de pressed to initiate repetitive character display or func tion operation comprising providing a keyboard capable of electronically sens ing key depression providing a first predetermined time period dete
29. ventional term associ ated with typewriters but it should be recognized that the displaying of a character on a display by means of illumination and electronic character generation may also be included within the terminology of printing Referring to FIG 1 the typewriter 10 has a keyboard 12 associated therewith In addition typewriter 10 also has a printing assembly 14 capable of physically mark ing a record sheet 15 to display characters by any con ventional typing or printing technology and the specif ics of that portion of the device do not constitute part of the invention described herein Keyboard processor 16 is the Intel 8048 microprocessor described above and is electronically connected to and interfaced with data lines leading to and from keyboard 12 The techniques of attaching these data lines to the keyboard processor 16 and the particular arrangement of keyboard 12 conventional and do not constitute any portion of the invention Keyboard processor 16 is electronically interfaced with the typewriter printer processor 18 hereinafter referred to as the printer processor 18 The printer processor 18 performs all the necessary control func tions and determinations for operating the printing as sembly 14 of the typewriter 10 to cause the printing of gt characters Printer processor 18 sends control signals to the printing assembly 14 and receives the necessary feedback signals fro
Download Pdf Manuals
Related Search