US3823805A

US3823805A - Typewriter controlled by a record medium

Info

Publication number: US3823805A
Application number: US00201403A
Authority: US
Inventors: E Richards
Original assignee: REDACTRON CORP
Current assignee: Unisys Corp; REDACTRON CORP
Priority date: 1971-11-23
Filing date: 1971-11-23
Publication date: 1974-07-16
Anticipated expiration: 1991-07-16

Abstract

Connected to a typewriter controllable by coded combinations of signals is a source of the combinations to control the operation of the typewriter. In addition to the usual graphic printing instructions, signals are generated to automatically vary the line advances following each carrier return, further signals are generated to control automatically the occurrences of the carrier returns, while still further signals control the automatic underlining or overprinting of graphics, i.e. characters, numerics and symbols.

Description

United States Patent 1191 Richards July 16, 1974 [54] TYPEWRITER CONTROLLED BY A 3,490,004 1/1370 Ross 13mg? RECORD MEDIUM 3,579,193 5 1 7| Bemier 3,630,336 l2/197l Johnson l97/l9 X Inventor: Edward Richards. Commack, 3,674,125 7/1972 Kolpek 197/19 [73] Assignee: Redactron Corporation, Hauppauge, i y 6I1 Pulfrey N .Y. Assistant Examiner-Eugene H. Eickholt Att 1,0 F'r an H x1e & S iecens 221 Filed: Nov. 23, 1971 H 3 Y p [21] Applr No.2 201,403 [57] ABSTRACT Connected to a typewriter controllable by coded comi" 197/19 197/1 binations of signals is a source of the combinations to [58] i 20 control the operation of the typewriter. in addition to arc the usual graphic printing instructions, signals are generated to automatically vary the line advances following each carrier return, further signals are generated [56] Remences cued to control automatically the occurrences of the carrier UNITED STATES PATENTS returns, while still further signals control the auto- 3,260,340 7/1966 Locklaretal. l97/2OX matic underlining or overprinting of graphics, i.e. 3,297,124 1/1967 Sims 197/19 characters, numerics and 5 mbols 3,386,552 6/1968 Lorber et a1 197/20 y 3,413,624 1 H1968 Murdoch et al. 197/20 x 18 Claims, 7 Drawin Fi res AUTIZARGIN M 6| KGR STOPA PR BUSYT AZ N CONTROL 24 065 FUNC TYPEWRITER SYSTEM CHARF LOOK MSB TAG s'ai s'nz 5&3 514 115 sir/c5111 n SELECTION rams MAIN 12 & Dams wi l? seven s-rrz r115 2 9 25mm; 1;

@15 SHIFT IRZEGISTER R4 MAG Mow s 1 1 112 teams Rl RlMAG LS5 GUL GSLSH 1 c smae K s27 LL55 :22; L BKMAG CHARF FUNC MAG CRMAG T sLAP g? LCMAG of Ocsw 1: FUNC (PAUL UCMAG 5 A smrr PULSE BUSYT 1&3. w, 4 o/csw E-g T FUNCTION :BKSP sme: oo/l1 (SSW D05 DOBSTOPA GEN :CR :LOOK :GCRZ

CLZAR [l r [j CHYPHEN :KCR PAUL :wo/zo E DCR SLAP CCONT HYPMEN KZSSYT 1 $225,, we 1&2. Ml. BUSYB is :GCRI CHOP 01:

:GCRZ P PAUL aKsP W CYGL A ,1 fl l1 GCYCLS 0 ocvcts arc/.5 CYCLC L1 crctc CYCLE FUENTES-" SHEET 5 f 3.823.805

CYcLB 0mm. CYCLAfiL, I/I GcYCLS {LOWER :BKIAAAG [UPPER 5 SPMAG LL ges FUNC LCMAG LOGIC. NETWORK L0 :SLAP 608 :UCMAG :PAUL :GSLSH :CONT GUL [SPACE LOOK] 2 1 oo HYFHENS F F, BUSYT KLC 605 :BKSP PROCS ;E& 602 CR 604 BusY'r CRMAG 7 SPACE) CYCLCV F 6 LOOK 603 OPERATlONAL MAGNET DIZNELRS 2 4!;521 {5022 iySRB $5,24- JYSRS JFSRG $52.7

DECODER DECODER DECODER DEC'ODER DECODER DECODER DECODER 702 703 704 705 706 70 7 MARGIN CONTROL g f- FIG. 7 708 7/2 MARGIN] D 709 .sroPA AUTO 713 F- F;

STOPA' TYIEWRITER CONTROLLED BY A RECORD MEDIUM This invention pertains to automatic typewriters and more particularly to record medium controlled type writers.

There is presently available a class of record medium controlled typewriters which are known as editing typewriters. An editing typewriter generally comprises a conventional typewriter which has been modified to communicate via signal paths to an external device. This modification generally permits the transmission to the typewriter of signals which perform the same functions within the typewriter as the stroking of keys by an operator, and the transmission from the typewriter of signals representing the keys stroked by an operator.

Within the external devices is a storage medium which can be in the form ofa punched record medium but is preferably in the form ofa magnetic tape or magnetic card In operation, as an operator strokes the keys of the typewriter to prepare a hard copy, representations ofthe key strokes are recorded on the storage medium. When the typing is finished there is available the printed (hard) copy as well as a machine readable version stored in the storage medium. If one now wishes to edit or correct the text, the hard copy is so modified and used as a guide for the operator while the typewriter is driven by the storage medium via the external device to create a new hard copy and a new machine readable version. Whenever, the new hard copy reaches a point where a modification is to be made, the operator stops the storage medium and manually keystrokes in the modifications and then restarts the storage medium. In this way, a clean modified hard copy can he obtained. It should be realized that the above description has been simplified and that most editing typewriters are quite sophisticated and at times require considerable interaction with the operator.

In particular, where the editing is directed to the addition or deletion oftext, it should be apparent that the original ends of lines of text which were followed by carrier or carriage returns may no longer be valid. In other words. the character in a stream of text which oc curs at the right hand margin may now be different. Therefore. some provision must be made to provide for the occurrence of a carrier return at the proper point and even to include a required hyphenation of characters. A first aspect ofthe invention concerns a solution of the problem.

In generating the hard copy. the format often requires changes in the spacing between lines. In other words, some portions of the text require single line advancing while others require double line advancing. Heretofore, such line advancing required the operator to insert a machine stop code and maintain a log which noted where the line advancing changed. With such a routine the line advance selector of the typewriter was set to the initial line advancing and the playback started. When the stop code was reached the playback stopped and the operator consulted the log to determine what the new line advancing should be. The operator set the line advance selector to the new position and restarted the playback. Another aspect of the invention concerns the automatic control and changing of line advancing not requiring the stopping of the playback or the intervention of the operator.

Quite often, the text requires that certain words or groups of words should be underlined. Typically present day editing typewriters perform this routine by typing the word or words, backspacing to the start of the section to be underlined and then typing in the underlining. However, it should be apparent that when the underlined section is broken by carriage or carrier returns, complications occur. Further. when such text requires modifying, these complications are magnified. While, in theory, the above-described routine can be used, it is a fact that operators are directed to ignore the routine and manually keystroke the underlining on the final copy. Another aspect of the invention is directed to apparatus for performing underlining in a way which avoids such complications.

If one carefully looks at an underlined character or other graphic, it should be apparent that it is a composite graphic composed of two unique symbols, one the character symbol and the other the underline symbol, both printed at the same print position. Present computer and communications technology often utilizes composite symbols to expand a font of hard copy graphics. A very common composite symbol is a character or number symbol on which is superimposed the slash symbol. One way of generating such composite symbol is to print the number or character (the variable element), backspace the typewriter, and then print, say, the slash or underline (the fixed element). Now, conventional typewriter keyboards have a limited number of keys. To double the number of graphics which can be printed, such typewriters are provided with a case shifting mechanism to shift the printing between upper case and lower case graphics. Therefore, each key, in effect, controls the printing of two graphics. When printing composite symbols, it is possible that the variable and fixed elements have different cases while the typewriter is resting in one of the case positions. If the fixed and variable elements are always printed in the same order, excessive case shifting may be required particularly when the composite symbols are strings of underlined lower case graphics since the underline symbol is upper case. Another aspect of the invention is directed to apparatus for minimizing case shifting.

The statements of the invention are defined by the appended claims while the other objects, features and advantages of the invention will be apparent from the following detailed description of the invention when read with the accompanying drawing which shows an exemplary apparatus for realizing the invention.

In the drawing:

FIG. I shows a block diagram of a typewriter system according to the invention;

FIG. 2 shows a logical diagram of the function generator of FIG. 1;

FIG. 3 shows a logic diagram for the shift pulse generator of FIG. 1;

FIG. 4.shows a logic diagram for of FIG. 1;

FIG. 5 shows a logic diagram for the selection magnet drivers of FIG. 1;

FIG. 6 shows a logic diagram for the operation magnet drivers of FIG. I; and

FIG. 7 shows a logic diagram for the margin control of FIG. 1;

The typewriter system to be described by way of example is an editing typewriter system. It will be assumed. for simplicity, that the original text of a first the cycle generator draft with editing is stored in a memory by virtue of an initial operator typing routine and that this text is to be played back to create a new clean hard copy. Such a system requires a memory for storing the text, as coded combinations of bits, means for converting the coded combinations of bits to electrical signals which either select graphics to be printed by the typewriter of select operational controls to be performed by the typewriter. and a typewriter which responds to such electrical signals. In addition, embedded in the text are other coded combinations of bits representing operation codes which control overall operation of the system. Accordingly, the system also includes control circuits responsive to the operation of op" codes to perform the desired control functions.

More particularly, FIG. 1 shows a typewriter system comprising a storage medium which includes a main memory l and a seven character shift register 12 interacting with a typewriter 13, via interfacing and con trol elements comprising a function generator 14, a shift pulse generator 16, a cycle generator 18, the selection magnet drivers 20, the operational magnet drivers 22 and the margin control 24.

The main memory can be. for example, a magnetic cassette recorder wherein the magnetic tape serially stores eight-bit bytes with the bits in parallel. In addition. the recorder is stepped forward to transmit on the eight lines of cable MMO the coded combination of signals representing the next byte of the series each time a shift data pulse is received on line SD. The shift register 12 can be a conventional seven-stage shift register wherein each stage stores the eight bits of a byte. The input lN of the shift register is connected to the cable MMO and receives the bytes therefrom in syn-' chronism with the outputting of main memory 10 by virtue of the pulses on line SD connected to the shift input SH. Shift register 12 has an initial clear input lC connected to line CLEAR, When a pulse is received at input IC the shift register is cleared to store all no op bytes, a particular coded combination of bits representing an op code saying no operation is to be performed. The output ofthe seventh and last stage of the shift register 12 is connected to the eight parallel lines MSB. T2, T1. R5, R4, R2, RI and LSB. The signals on these lines represent the eight bits of a byte. The bit on line MSB is used to determine whether the byte represents an op code. If this bit is a one the byte is an op code, if it is a zero the byte generally represents either a graphic or an operation to be performed by the typewriter. The bit ,on line LSB indicates the case of a graphic represented by the byte. lfthis bit is a one then the graphic is lower case. if a zero then upper case. The remaining six bits define either op codes when MSB l or. when MSB 0, the coded combinations of signals eventually transmitted to the typewriter for graphic selection. In addition, the eight outputs of the seventh stage of the the shift register are collected in an eight line cable SR7 and fed to function generator 14 and also to margin control 24. In fact, the eight outputs of each stage of the shift register are fed to margin control 24, as indicated by eight line cables SR1 to SR7.

While typewriter 13 can take many forms, the system will be described with respect to the lBM SELECTRlC Input/Output Writer. In particular, the typewriter receives in parallel signals on lines DATAC, T2MAG. TlMAG. RSMAG. R4MAG, RZMAG and RlMAG from selection magnet drivers 20. The receipt of a coded combination of these signals selects and prints a graphic. In addition, the typewriter 13 receives signals on lines SPMAG, BRMAG, CRMAG, LCMAG and UCMAG from operational magnet drivers 22. The receipt of a signal from each of the lines individually causes the typewriter to space. backspace. carrier return, shift to lower case and shift to upper case. respectively. The typewriter emits a signal on line KLC when it is in the lower case shift position, a signal on line KCR while performing a carrier return and a signal on line BUSYT when the typewriter is busy performing any of these operations including printing but not case shifting. Added to the typewriter is a switch connected to the right margin setting of the typewriter. This switch causes line MARGlN to emit a signal when the carrier is in the selected right margin zone. This switch can be considered as an alerting means for generating an initiate start of line print positioning movement.

The shift pulse generator 16 primarily generates pulses on line SD to shift the bytes from memory 10 and through shift register 12 and on line DOB to operate cycle generator 18. The times of generation of these pulses is controlled by signals on line NOP from function generator 14, line STOPA from margin control 24. line BUSYT from typewriter 13, and line BUSYB from cycle generator 18. The shift pulse generator 16 includes several manually operable switches which generate in addition to other signals used internals. signals on line CHARF. line AUTO and line CLEAR.

Cycle generator 18 primarily controls the number of operation cycles to be performed and when by the typewriter for each byte transmitted from the memory and in certain cases, as will hereinafter become apparent, which operational motions the typewriter 13 is to perform. Cycle generator 18 generates signals on lines BUSYB, CYCLA, CYCLB, CYCLC and GCYCLS under control of signals on line DOB from shift pulse generator 16, on line STOPA from margin control 24, on line BUSYT from typewriter 13, on lines PAUL, SLAP, and NOP from function generator 14. and lines GC R1 and GCRZ from operational magnet drivers 22. Selection magnet drivers 20 primarily receive the six central bits of the bytes from shift register 12 on lines T2, T1, R5, R4, R2 and R1 and transfer those bits as signals to typewriter 13 under the control of a signal on line PROCS from operational magnet drivers 22, a signal on line BUSYT from typewriter l3 and a signal on line FUNC from function generator 14. Furthermore, selection magnet drivers 20 can generate the signals representing an underline symbol or a slash symbol in response to signals on lines GUL and GSLSH, respectively, from operational magnet drivers 22.

Operational magnet drivers 22 primarily generate the typewriter operational control signals transmitted on lines SPMAG. BKMAG. CRMAG, LCMAG, and UCMAG to control the space, backspace, carrier return, upper and lower case shift operations. respectively, of typewriter 13 as well as generating the signals on lines GUL, GSLSH and PROCS to selection magnet drivers 20, in addition to signals on lines OCR! and GCR2 to cycle generator 18. The generation of these signals is under control of signals on lines KLC, KCR and BUSYT from typewriter 13, on line LSB from shift register 12, on lines FUNC, SLAP, PAUL. CONT. SPACE, DCR, HYPHEN. CR and BKSP from function generator 14, on line LOOK from margin control 24,

and lines CYCLA, CYCLB, CYCLC and GCYCLS from cycle control 18.

Margin control 24 controls the generation of carrier returns when priming extends into the right hand margin region by generating signals on lines STOPA and LOOK in response to signals on lines MARGIN and KCR from typewriter 13, on cables SR1 to SR7 from shift register 12 and lines AUTO and CHARF from shift pulse generator 16.

Before describing the operation of the system several conventions should be noted. While all lines, and inputs and outputs connected thereto. in FIG. I are shown carrying one logic condition, in many cases the line is a pair with the other line carrying the inverse of that logic condition. Thus, line LSB is actually a pair oflines LSB and LSB. Furthermore. with respect to FIGS. 2 to 7, all inputs are shown connected to the actual line of the pair. However, for simplicity, in some cases the output connected to the inverse line of the pair is not shown. Nevertheless, it should be apparent that any inverse function can be obtained by passing the signal through an inverter.

In addition. a signal name will be used as a common denominator. Thus, for example, the LSB signal is carried on line LSB, which is connected to the LSB output of shift register 12 and the LSB input of operational magnet drivers 22. Moreover, positive logic will be used. Therefore, when a signal such as LSB is present. it is up" or high while its inverse LSB is absent. down" or low", and when a signal is absent, its down or low and its inverse present, up or high.

The operation of the typewriter system will be described by making reference to FIG. 1. At the start of the operation, it is assumed that the typewriter 13 is on. is at the left-hand margin and is in a lower case position. and that the cassette recorder of memory is in the read position, and is at the first byte which will be a lower case character.

An operator depresses a clear switch (SW and then an automatic switch ASW in shift pulse generator 16 resulting in the generation of the CLEAR and AUTO pulse signals plus internally conditioning pulse generator 16 to operate. The CLEAR signal initializes certain flip-flops throughout system and most particularly, is fed to the clear input IC of shift register 12 to force set each stage therein to store a byte representing a no op code. Function generator 14 decodes the no op code representation on lines SR7 and generates the NOP sig nal. The NOP signal is fed to shift pulse generator 16 to make it a free running pulse generator until the NOP signal terminates. The AUTO pulse signal within pulse generator 16 causes the generation of a DOB pulse which is fed to cycle generator 18 but it has no effect therein as long as the NOP signal is present. The DOB pulse signal causes pulse generator 16 to generate an {ID pulse signal which is fed to main memory 10 and to shift register 12 resulting in the reading of the first byte from memory 10 into stage one of shift register 12 while right shifting by one stage the contents of shift register 12. Again, the seventh stage contains a no op code byte and the cycle is repeated. In fact, there are seven such cycles. After the seventh cycle, stage seven of shift register contains the first byte on the tape of memory 10, that byte being a lower case character to be printed which is not a no op code byte. Accordingly, function generator 14 stops generating the NOP signal terminating the free-running of pulse generator 16 and conditioning cycle generator 18 to be responsive to DOB pulse signals. The last of the free-running DOB pulse signals occurs just after the termination of the NOP signal and causes cycle generator 18 to generate a CYCLC signal, by setting the third stage of the shift register therein, which is fed to operational magnet drivers 22. In addition, a BUSYB signal is fed to pulse generator 16. Now, since the byte in stage seven is lower case, an LSB signal is transmitted to operational magnet drivers 22; and since typewriter I3 is in the lower case position it transmits a KLC signal to drivers 22. Since the cases agree (are the same) operational magnet drivers 22 feed a PROCS signal to selection magnet drivers 20 which have been receiving the six central or selection bits of the byte in stage seven of shift register 12. Drivers 20 then transmit a coded combination of seven signals via lines TZMAG, TIMAG, RSMAG. R4MAG, RZMAG, RlMAG and DATAC to typewriter. The first six signals correspond to the six selection bits and select the graphic, while signal DATAC generated by drivers 20 initiates a print cycle by the typewriter 13. As long the pring cycle is present typewriter 13 generates a BUSYT signal. The leading edge of the BUSYT signal acts as a shift pulse in the shift register of cycle generator 18 and since the third of last stage was set it now clears causing the termina tion of the CYCLC and BUSYB signals. The termination of the BUSYB signal in shift pulse generator 16 breaks an interlock which will permit it to generate another shift pulse in the following manner. The leading edge of the BUSYT signal causes shift pulse generator 16 to internally generate a pulse which passes through the now broken interlock to generate another shift pulse signal SD followed by a DOB pulse signal. The DOB pulse signal causes the read out of the next byte and the generation of another CYCLC signal as described above. The new byte which will be assumed to be an upper case graphic to be printed is being presented to selection magnet drivers 20. However. since the typewriter operation is much slower than the memory transfer the system waits until the end of typewriter operation as indicated by the termination of the BUSYT signal. The absence of this signal in operational magnetic drivers 22 permits the generation ofa PROCS signal in response to the CYCLC signal to initiate a new print cycle as described above and such a cycle would begin as long the cases agree. However, it should be recalled that this second byte was an upper case graphic. Therefore, the LSB signal is absent. But typewriter 13 is in the lower case position and generating the KLC signal. The presence of the KLC signal and the absence of the LSB signal indicating disagreement and that the next graphic is upper case causes operational magnet drivers 22 to transmit an UCMAG signal to typewriter [3 which shifts to the upper case position in response thereto. After this case shift the KLC signal disappears. The cases now agree and the PROCS signal is generated.

In a similar way if the LSB signal were present indieating a lower case graphic and the KLC signal were absent indicating an upper case position of the typewriter 13, operational magnet drivers 22 would transmit an LCMAG signal to typewriter 13 causing a shift to the lower case position and the generation of the KLC. Then both KLC and LSB are present indicating that the cases agree, and such agreement permits the generation of the PROCS signal in response to the CYCLC signal. Note that case shifting does not cause the generation of a BUSYT signal by the typewriter.

The next operation to be described is the generation of a composite graphic. Two examples will be given, one is a Slashed symbol and the other is an underlined symbol. in each case there are three steps to the operation. There are two prim cycles and one backspace cycle so that both elements of the composite graphic are printed in the same space, i.e., one is superimposed" on the other. The order in which the elements are printed is a function of the cases involved. Case shifing can be minimized when the cases of the two elements disagree. Then, the element having the same case as the present case position of the typewriter is printed first.

First it will be assumed that the composite graphic is a slashed symbol to be printed. Now' the slash element is a lower case graphic while the slashed graphic can be either depending on the case of the symbol to be slashed. A slashed graphic is indicated by the MSB bit equal to one with the case of the position to be determined as usual by the value of the LSB bit. Usually, such composite graphics are not printed but to print such a graphic, the operator depresses the print switch PSW in the function generator.

When the byte representing a slashed graphic is in stage seven of the shift register 12, function generator 14 senses that the MSB signal is present and generates a SLAP signal which is fed primarily to cycle generator 18 and operational magnet drivers 22. Cycle generator 18 in response thereto causes the generation of a GCYCLS signal and sets the three stage shift register to its first stage resulting in the generator of the CYCLA signal which, in turn, causes the generation of the BUSYB signal. The presence of the BUSYB signal in shift pulse generator 16 halts any further generation of SD shift pulse signal. Now, either the slash or the symbol is printed first. If the symbol is upper case and the typewriter is in the upper case position (the upper cases agree) the symbol will be printed first otherwise the slash will be printed first.

It will first be assumed that the upper cases agree. Therefore. the symbol is printed first. The coincidence of the absence of the KLC signal, the absence of the LSB signal and the presence of the SLAP signal result in the generation of the PROCS signal by operational magnet drivers 22 and the symbol is printed as described above. The print cycle causes the usual generation of the BUSYT signal by typewriter which steps the shift register in cycle generator 18 to stage two terminating signal CYCLA and initiating signal CYCLB.

However, if the symbol were not to be printed first because there was not upper case agreement then the slash would be printed first. However, depending on the case position of the typewriter a case shift may be necessary because the slash is a lower case symbol. There are two possibilities. First, if the typewriter is in lower case then the coincidence of the presence of the KLC signal, the presence of the CYCLA signal and the presence of the SLAP signal causes operational magnet drivers 22 to transmit a GSLH signal to selection magnet drivers 20. In response to this signal magnet drivers 20 transmit the proper coded combination of signals to typewriter 13 to select the slash symbol and initiate a print cycle with the generation of the usual BUSYT signal which steps the shift register in cycle generator 18 to the second stage with generation of the CYCLB sig nal. Second, if the typewriter had been in the upper case position, then it must be shifted to lower case before printing the slash. The coincidence of the absence of the KLC signal, the presence of the CYCLA and the presence of the SLAP signal in operational magnet drivers 22 causes the transmission of the LCMAG signal to typewriter 13 which switches to lower case and starts generating the KLC signal. Now, there is lower case agreement and the routine continues according to the above described first possibility resulting in the printing of the slash and the stepping of the shift register in cycle generator 18 to the second stage with the generation of the CYCLB signal.

For any of the above described conditions, it is seen that the CYCLA cycle results in the printing of either the slash or the symbol and the stepping to the C YCLB cycle. AT the end of this print cycle the coincidence of the absence of the BUSYT signal and the presence of the CYCLB signal causes operational magnet drivers 22 to transmit a BKMAG signal to typewriter 13. In response thereto, the typewriter backspaces and gener ates the usual BUSYT signal which steps the shift re gister in cycle generator 18 to the third stage to cause the termination of the CYCLB signal and the initiation of the CYCLC signal. Now, if the slash had been printed first it is now necessary to print the symbol. From this point the situation is the same as the usual printing of an unslashed graphic in cycle CYCLC. Hence, the description will not be repeated except to say that the onset of the BUSYT signal clears the shift register in cycle generator 18 resulting in the termination of the CYCLC and BUSYB signals.

However, if the symbol had been printed first, it is now necessary to print the slash. It should be recalled that to print the symbol first at least the typewriter was in the upper case position. Since the slash symbol is lower case, there must be a down shifting to lower case. The coincidence of the absence of the KLC signal, the presence of the SLAP signal and the presence of the CYCLC signals causes operational magnet drivers 22 to generate an LCMAG signal. The receipt of this signal causes typewriter 13 to shift to the lower case position and the generation of the KLC signal. The coincidence of the presence of the KLC signal, the presence of the CYCLC and the presence of the SLAP signals cause the transmission of the GSLSH signal to selection magnet drivers 20. The slash is printed as described above and the BUSYT signal is generated which clears the shift register in cycle generator 18 resulting in the termination of the CYCLC and BUSYB signals.

For all conditions the termination of the BUSYB signal breaks the interlock in shift pulse generator 16 so that when the BUSYT signal terminates, shift pulse generator 16 generates the SD and DOB pulse signals reading a new byte out for processing. Unless the new byte in stage seven of'shift register 12 is a slashed graphic the SLAP signal terminates.

Whereas the slashed graphic operation occurred on a signal graphic basis with the graphic byte itself controlling the generation of the composite graphic, the underline routine is a block operation. In particular, a first op code byte indicates that all succeeding bytes representing graphics are to be underlined until a second op code byte indicates the end of the underlining. The first op code can have one of two values, one associated with continuous underline wherein all positions with the exception of operations such as carrier return,

are underlined and the other associated with word underline wherein space positions are also not underlined.

Word underlining will be described first. When the op code for word underlining is in stage seven of shift register 12, function generator 14 starts generating a WORD signal used internally and a NOP signal which is fed to shift pulse generator 16 to cause the generation of another SD and another DOB pulse signal. If the new byte shifted in stage seven is valid for underlining, the function generator 14 in response to the WORD signal and to this byte generates a PAUL signal. Now, effectively, the PAUL signal assumes the same role that the SLAP signal performed in generating slashed graphics. The routines are generally the same with a major difference being that the underline symbol is upper case. Therefore, the PAUL signal cooperating with the DOB pulse signal sets the shift register in cycle generator 18 to the first stage causing the generation of the CYCLA, GCYCLS and BUSYB signals as described above. The BUSYB signal in shift pulse generator l6 temporarily terminates further generation of the SD and DOB pulse signals. Now, either the underline ofthe symbol is printed first. If the symbol is lower case and the typewriter is in the lower case position (the lower cases agree) the symbol is printed first otherwise the underline which is an upper case symbol will be printed first.

It will be first assumed that the lower cases agree. Therefore. the symbol is printed first. The coincidence of the presence of the KLC signal. the presence of the LS8 signal and the presence ofthe PAUL signal result in the generation of the PROCS signal by operational magnet drivers and the symbol is printed as described above. The print cycle causes the usual generation of the BUSYT signal by typewriter 13 which steps the shift register in cycle generator 18 to stage two terminating the CYCLA signal and initiating the CYCLB signal.

However. ifthere were not lower case agreement the underline is printed first. Two possibilities then arise. First, if the typewriter is in upper case, then the coincidence of the absence of the KLC signal, the presence of the CYCLA signal and the presence of the PAUL signal causes operational magnet drivers 22 to transmit a GUL signal to selection magnet drivers 20. In response to this signal magnet drivers 20 transmit the proper coded combination of signals to typewriter 13 to select the underline symbol and initiate a print cycle with the generation of the usual BUSYT signal which steps the shift register in cycle generator 18 to stage two with the generation of the CYCLB signal. Second, if the typewriter had been in the lower case position, then it must be shifted to upper case before printing the underline. The coincidence of the presence of the CY- CLA. PAUL and KLC signals causes the transmission of the UCMAG signal to the typewriter which switches to upper case and terminates the KLC signal. Now there is upper case agreement and the routine continues according to the above-described first possibility which ends with the generation of the CYCLB signal.

At the end of this first print cycle, the coincidence of the absence of the BUSYT signal and the presence of the CYCLB signal causes operational magnet drivers 22 to transmit a BKMAG signal to typewriter 13. In response thereto, the typewriter backspaces and gener- Lil ates the usual BUSYT signal stepping the shift register in cycle generator 18 to the third stage which terminates signal CYC LB and initiates signal CYCLC. If the underline had been printed first the symbol must now be printed. ln such a case the situation is the same as printing any non-underlined graphic in cycle C YCLC. Therefore. the description will not be repeated except to say that the onset of the BUSYT signal clears the shift register in cycle generator 18 resulting in the termination of the CYCLC and BUSYB signals.

However, if the symbol were printed first, it is now necessary to print the underline. If the symbol were printed first, the typewriter was in the lower case position. Since the underline is upper case, there must be a shift to upper case before the printing of the underline. The coincidence of the presence of the KLC, PAUL, and CYCLC signals causes operational magnet drivers 22 to generate a UCMAG signal. The receipt of this signal by typewriter causes a shift to upper case and the termination of the KLC signal. The coincidence of the absence of the KLC signal and the presence of the PAUL and CYCLC signals causes the transmission of the GUL signal to selection magnet drivers 20. The underline is printed as described above and the BUSYT signal is generated which clears the shift register in cycle generator 18 resulting in the termination of the CYCLC and BUSYB signals.

For all conditions the termination of the BUSYB signal breaks the interlock in shift pulse generator 16 so that when the BUSYT signal ends, shift pulse generator 16 generates the SD and DOB pulse signals reading a new byte for processing.

If the byte had represented a space operation, function generator 14 would have generated a SPACE signal. The SPACE signal fed to operational magnet drivers 22 would result in the generation of a SPMAG signal fed to typewriter 13. The typewriter would space and generate the usual BUSYT signal.

If the underlining were to be continuous the op code for continuous underline would have been detected and the CONT instead of the WORD signal would be generated in function generator 14. The CONT signal would cause the generation of the PAUL signal so the underlining operations are the same except that the CONT signal is also fed to operational magnet drivers 22. Therefore, when a SPACE signal is detected during the CYCLC cycle, a GUL signal is generated so that the space is simply underlined. However, as will hereinafter be apparent, automatic carrier turn operations from the right margin can use a space op code to generate a carrier return. Therefore, to prevent an underlining from being performed in such a case the following provision is made. When the carrier is in the right margin region the typewriter 13 generates a MAROIN signal. Margin control 24 in response thereto transmits a LOOK signal to operational magnet drivers 22 to prevent an underline of a space under these conditions.

Underlining continues until the byte in stage seven of shift register 12 represents an end of underline control. Function generator 14 detects this byte and terminates either the WORD or CONT signal while generating a NOP signal. When the WORD or CONT signal terminates underlining is over while the NOP signal permits the accessing of the next byte for processing.

The carrier return operations will not be described. There are two carrier return operations. One results in a carrier return to the left margin and a single line advance (a single start of line print positioning movement), the other results in a carrier return to the left margin with a double line advance (a double or multiple start of line prim positioning movement). In addition, there are two ways in initiating either carrier return operation. One is by the reading ofa carrier return op code from the memory, the other by sensing when the carrier is within the righthand margin region.

Whether a single or double line advance is to be performed is determined by reading op code bytes associated therewith from the memory. There is a special op code byte associated with single line advance and another op code byte associated with double line advance. When one of these special op code bytes is read, all subsequent carrier returns will also perform the line advance associated with that op code byte until the other special op code byte is read.

The first function to be described will be the generation of the control signal indicating the number of line advances per carrier return.

When an op code byte representing a double line advance is in stage seven ofshift register 12, function generator l4 detects this byte and sets a flip-flop which starts generating a DCR signal which is transmitted to operational magnet drivers 22. This DCR signal will remain present until the op code byte representing a single line advance is in stage seven of shift register 12. At that time, function generator 14 detects that op code byte and resets the flip-flop terminating the DCR signal. Whenever either of these op code bytes is in stage seven function generator 14 also transmits a NOP signal to shift pulse generator [6 to permit the generation ofanother SD pulse signal and another DOB pulse signal so that the next byte can shifted into stage seven of shift register 12.

Now, assume that the last read line advance op code byte whenever it occurred was for single line advance and that the byte in stage seven of shift register 12 is a carrier return op code byte. Therefore, function decoder 14 is not generating the DCR signal. However, the function decoder 14 decodes the carrier return op code and generates and transmits the FUNC signal and CR signal to operational magnet drivers 22. ln addition, the DOB pulse signal associated with the shifting of the carrier return op code byte into position sets the third stage of the shift register in cycle generator 18 causing the generation of the CYCLC and BUSYB signals. The BUSYB signal sets the interlock in shift pulse generator 16 while, effectively, the coincidence of the presence of the CYCLC, FUNC and CR signals causes operational magnet drivers 22 to transmit a CRMAG signal to typewriter 13. In response thereto, typewriter 13 starts the carrier return action and generates a KCR signal indicating a carrier return is being performed and generates the usual BUSYT signal. The KCR signal is fed to operational magnet drivers 22 but has no effect at this time. The BUSYT signal clears the shift register in cycle generator 18 and terminates the CYCLC signal and BUSYB signal breaking the interlock in shift pulse generator 16. The BUSYT signal also triggers shift pulse generator 16 to generate another SD pulse signal and another DOB pulse signal to make the next byte available.

Had the DCR signal been present indicating a double line advance the operation would have been the same up to the transmission of the KCR signal by the typewriter l3 during the carrier return. Then the coincidence of the presence of the KCR and DCR signals in operational magnet drivers 22 causes the setting of a flip-flop. The flip-flop starts generating a GCR2 signal that is fed to cycle generator 16 to sustain the generation of the BUSYB signals as long as the GCR2 signal is present in spite of the fact that BUSYT signal terminates the CYCLC signal. At the end of the BUSYT signal, the coincidence of the presence of the GC R2 signal and the absence of the BUSYT signal causes operational magnet drivers 22 to transmit another CRMAG signal to typewriter 13. In response thereto, typewriter l3 performs the second carrier return and generates another BUSYT signal. This BUSYT signal resets the flip-flop terminating the GCRZ signal which terminates the BUSYB signal so that shift pulse generator 16 can generate the next SD and DOE pulse signals to make the next byte available for processing.

Now, an automatic or typewriter controlled carrier return routine will be described. As the graphics are being printed the carrier moves from the left-hand margin toward the right-hand margin. When the carrier enters the right-hand margin zone a switch is actuated which will remain actuated as long as the carrier is in a region of at least seven print positions. The actuation of the switch causes the transmission ofa MARGIN signal by typewriter 13 to margin control 24. Margin control 24 tests to see whether anyone of the next seven upcoming bytes, i.e., the bytes stored in shift register 12 are possible line end bytes. A line end is a byte representing a carrier return, a byte representing a space or a byte representing a hyphen. If such a byte is stored in shift register 12, byte processing continues until such byte is in the seventh stage. If such a byte is not present there is a need for operator intervention. The first situation will be described first. The MARGIN signal causes the setting of a flip-flop in margin control 24 which transmits a LOOK signal to operational magnet drivers 22. Now, three possibilities arise, the byte is l a carrier return op code byte, (2) a space op code byte or (3) a hyphen op code byte. For possibility I, when the op code carrier return byte reaches the seventh stage of shift register 12 it is processed as any normal carrier return op code byte and when the carrier moves toward the left-hand margin the KCR signal generated by the typewriter is fed to margin control 24 and resets the flip-flop terminating the LOOK signal. If the byte were a space op code byte, then when this byte reaches the seventh stage of shift register 12 function generator 14 transmits the SPACE signal to operational magnet drivers 22. The coincidence of the LOOK and SPACE signals therein prevents the usual processing of a space operation but instead causes the transmission of a CRMAG to typewriter 13 which initiates a carrier return and the process continues as if the op code byte had called for a carrier return, i.e., according to possibility I. Now, if the space op code occurred in a continuous underlining string, the LOOK signal in operational magnet drivers 22 would prevent the generation of the underline. If the op code byte were a hyphen, i.e., possibility 3, it is necessary to print the hyphen and then generate the carrier return. Thus, when the hyphen op code byte reaches stage seven of shift register 12, function generator 14 generates the HYPHEN signal and the hyphen symbol is printed as usual. When the usual BUSYT signal is generated, the coincidence of the BUSYT, LOOK and HYPHEN signals set a flip-flop in operational magnet drivers 22 which starts generating a GCRl signal. The GCRZ signal is transmitted to cycle generator 18 to keep the BUSYB signal present regardless of the state of the CYCLC signal. When the BUSYT signal terminates at the end ofthe hyphen print cycle, the GCRl signal causes operational magnet drivers 22 to transmit a CRMAG signal to typewriter 13 and the process continues as with any other carrier return process except the BUSYT signal resets the flipflop that had been set in operational magnet drivers 22 to terminate the OCR] signal.

Now. assume that none of the bytes in shift register 12 represented an end of line byte and that therefore the operator must intervene to hyphenate the word in progress and manually generate the carrier return. The LOOK signal interval to the margin control 24 then causes the generation ofa STOPA signal which is transmitted to shift pulse generator 16 to reset the flip-flop therein which had been generating a RUN signal and the automatic generation ofthe SD and DoB pulse signals terminates. The STOPA signal is also fed to cycle generator 18 to prevent the automatic setting of the stages of the shift register therein. Now, the bytes are transferred from memory under the control of the operator. The operator depresses and releases the switch OCSW in shift pulse generator 16 momentarily generating a CHAR signal which sets a flip flop which generates a CHARF signal. in response to the generation of the CHAR signal, shift pulse generator 16 generates one DOB pulse signal and one byte is processed and the BUSYT signal causes the generation of an SD pulse signal making the next byte available. To process this next byte the operator must again depress the switch OCSW. This continues until the operator finds a convenient position to manually insert a hyphen, via

the keyboard of the typewriter and then to manually insert, via the keyboard of the typewriter, a carrier return driving the carrier to the left-hand margin. Then, the operator depresses and releases the automatic switch ASW in shift pulse generator 16 to generate an AUTO pulse signal. The AUTO pulse signal interval to shift pulse generator 16 causes the generation of the DOB and SD pulse signals while the AUTO pulse signal received by margin control 24 resets the flip-flop which was set by the MARGIN signal to terminate the LOOK and STOPA signals.

Finally, the system can be stopped by the operator depressing a stop switch SSW in shift pulse generator 16.

The function generator 14 is shown in FIG. 2 comprising decoders 201 to 212 each having inputs connected to the lines ofcable SR7. Each decoder decodes a unique coded combination of the bits of the byte on the lines of cable SR7 to generate a signal representing the byte. The bytes decoded by each decoder are indicated by the labeling of the box representing the decoder.

Furthermore, the

decoders

205, 206 and 207 are associated with underlining processes which are generally multibyte processes and therefore, require some memory function. Accordingly, set-reset flip-

flops

213 and 214 are provided. The output of word underline decoder 205 is connected to the set input S of flip-flop 213 and the output of continuous underline decoder 206 is connected to set input S of flip-flop 214. The output of end underline decoder 207 is connected to the reset inputs R of both flip-flops while the CLEAR signal line feeds the clear inputs of both flip-flops to force reset them at the start of operation of the system. The output 1 of flip-flop 213 is connected to the WORD signal line and the output 1 of flip-flop 214 is connected to the CONT signal line.

OR-circuit 218 which transmits the NOP signal has one input connected to the output of NO OP decoder 209 and a second input connected to the output of AND-circuit 216 whose inputs are connected to the output of slash decoder 208 and the inverting output of manually operable print switch PSW. Thus, if either a no op code byte is sensed for a slashed byte which is not to be printed is detected the NOP signal is generated to prevent processing of the byte and to give an immediate stepping to the next byte. The output of AND- circuit 215 is connected to the SLAP signal line while its inputs are connected to the output of slash decoder 208 and the direct output of print switch PSW so that when a detected slashed byte is to be printed the SLAP signal is generated.

The output of AND-circuit 219 is connected to line PAUL while its inputs are connected to the output of under-lineable character decoder 210 and to the output of OR-clrcuit 220 whose inputs are connected to the WORD and CONT signal lines. There is a signal on line PAUL when underlining is called for as indicated by either the WORD or CONT signals provided the byte is underlineable, i.e., not a carrier return or backspace operation, for example.

Set/reset flip-flop 22] having its output I connected to line DCR remembers whether there is to be single or double line advances. The set input S of flip flop 221 is connected to the output of double advance decoder 212 while the reset input R is connected to the output ofsingle line advance decoder 211.

Finally, the output of OR-circuit 222 is connected to the FUNC line while its inputs are connected to the SPACE, BKSP and CR signal lines.

Shift pulse generator 16 shown in FIG. 3 centers around the circuits for generating the SD pulse signals for shifting bytes out of the memory and the DOB pulse signals for initiating processing of such bytes.

Normally, the onset of a BUSYT signal at the input of one shot multivibrator 301 causes it to transmit a pulse to one shot multivibrator 302 which is triggered by the trailing edge of such pulse to transmit a pulse to one input of AND-circuit 303. The second input of AND-circuit 303 receives the BUSYB signal. This is the interlock which prevents byte shifting for the memory as long as the previous byte is being processed. The output of AND-circuit 303 is connected to one input of OR-circuit 304' whose output is connected via inverter 305 to the input of one shot multivibrator 306. Thus, when the pulse from one shot multivibrator 302 passes through AND-circuit 303 it triggers one shot multivibrator which transmits from its positive output a pulse to line SD. The trailing edge of this pulse triggers one shot multivibrator 307 since the negative output of one shot multivibrator 306 is connected to the input of one shot multivibrator 307. The output of one shot multivibrator 307 is connected to one input of AND-circuit 308 whose other input is connected to the RUN signal line. If the RUN signal is present which is the usual case, one shot multivibrator 307 triggers one shot multivibrator 311 since the output of AND-circuit 308 is connected to one input of OR-circuit 309 whose output is connected via inverter 310 to the input of one shot multivibrator 311. The output of one shot multivibrator 311 is connected to the DOB signal line so that whenever this one shot multivibrator is triggered a DOB pulse signal is generated for initiating processing of the available byte.

The RUN signal is generated by set/reset flip-flop 312 whose output 1 is connected to line RUN. The set input S of the flip-flop 312 is connected to manually operable auto switch ASW which effectively generates a pulse whenever depressed. The reset input R of flipflop 312 is connected to the output of three-input OR- circuit 314. The first input thereof is connected to stop switch SSW which can be similar to auto switch ASW. The second input thereof is connected to line CLEAR which is connected to the output of initial clear switch CSW which can be similar to auto switch ASW. The third input thereof is connected to the output of AND- circuit 315 whose inputs are connected to the STOPA, DOB and NOP' signal lines to stop automatic pulse generation when the operator must manually end a line of text through the assistance of the one character switch OC SW.

One character switch OCSW which can be similar to auto switch ASW has its output connected to line CHAR which is connected to the set input S of set/reset flip-flop 316 and to a second input of OR-circuit 309. The reset input offlip-flop 316 is connected to the line SD while its outputs l and 0 are connected to the CHARF and CHARF' signal lines, respectively. Note each time switch OCSW is depressed a CHAR pulse signal is generated which results in the generation of a DOB pulse signal. The third input of OR-circuit 309 is connected via line AUTO to the output of auto switch ASW to initiate the processing of the first available byte when the system is started or restarted.

Since no op code bytes are not processed by the typewriter 13 and normal generation of the SD pulse signals is initiated by the BUSYT signal from the typewriter it is necessary to provide an alternate path. This is performed by the AND-circuit 317 having inputs connected to the NOP and DOB signal lines and an output connected to the second input of OR-circuit 304.

Cycle generator 18 shown in FIG. 4 centers around three stage shift register 401 comprising stages 401-1, 401-2 and 401-3. Shifting is from stage 401-1 to stage 401-2 to stage 401-3 in response to shift pulses received at the shift input SH connected to the BUSYT signal line. The shift register is open ended, i.e., when stage 401-3 is set the next shift pulse clears the register. The register can also be cleared by a pulse signal on line CLEAR connected to the 1C input. Shift register 401 is loaded by either setting stage 401-] by feeding a pulse into set input S1 which is connected to the output of AND-circuit 402, or by setting stage 401-3 by feeding a pulse into set input S3 which is connected to the output of AND-circuit 403.

The inputs of AND-circuit 402 are connected to the STOPA signal line, the DOB signal line and the output of OR-circuit 404 whose inputs are connected to the SLAP and PAUL signal lines. Thus, it should be apparent that stage 401-1 is set to generate the CYCLA signal at its output only when composite graphics are to be printed. The inputs of AND-circuit 403 are connected to the STOPA', DOB, NO? and GCYCLS' signal lines. Note the GCYCLS' signal line is connected to the output ofinverter 405 whose input is connected to the output of OR-circuit 404. Stage 401-3 is set and generates the CYCLC signal during the processing of non-composite graphics. The output of stage 401-2 is connected to line CYCLB and transmits a signal thereon when set to initiate typewriter backspacing.

The interlock signal BUSYB is generated by inverter 406 having an input connected to the output of OR- eircuit 407 whose inputs are connected to the CYCLA, CYCLB,CYCLC,GCR1 and GCRZ signal lines. lf any one of these signals is present the BUSYB signal is absent and the BUSYB signal present. If none of these signals are present the reverse is true.

Selection magnet drivers 20 shown in FIG. 5 generate the coded combinations of signals fed to the typewriter to select the graphic to be printed. Generally, the graphic is selected according to the coded combination of selection bits of the available byte as represented by the T2, T1, R5, R4, R2 and R1 signals from shift register 12. Each one of these signals is connected to an input of the two-input AND-

circuits

501, 502, 503, 504, 505 and 506, respectively. The second input of each of these AND-circuits is connected to the output of AND-circuit 507 whose inputs are connected to the BUSYT', FUNC' and PROCS signal lines. The output of AND-circuit 507 controls when the graphic should be selected. Whenever the selected graphic is to be printed a DATAC signal is generated in parallel with the coded combination of selection signals. The DATAC signal is generated by OR-circuit 508 which also has an input connected to the output of AND- circuit 507. It will be recalled that when composite graphics are to be printed, it is necessary to generate the slash or underline symbol. The selection signals for the slash signal are derived from the GSLH signal which is fed to a second input of OR-circuit 508 and to an input of each of the two input AND-

gates

509 and 510 whose second inputs receive the BUSYT signal. The underline symbol is selected by merely generating a DATAC signal, therefore the GUL signal is fed to the third input of OR-circuit 508. Finally, the outputs of AND-

circuits

509 and 503 are connected to inputs of OR-circuit 511 whose output is connected to line RSMAG, and the outputs of AND-

circuits

506 and 510 are connected to inputs of OR-circuit 512 whose output is connected to line RIMAG. The outputs of AND-

circuits

501, 502, 504 and 505 ae connected respectively to lines T2MAG, TlMAG, R4MAG and R2MAG, respectively. It should be noted that lines DATAC, TZMAG, TlMAG, RSMAG. R4MAG. RZMAG, and RlMAG are preferably connected to power amplifiers and level shifters (not shown) which are known to those skilled in the art.

Operational magnetic drivers 22 shown in FIG. 6 consists of two circuits; one associated with carrier return operations and the other associated with backspacing, spacing, printing and case shifting operations. The carrier return circuits controllably generate a signal on line CRMAG connected to the output of AND- circuit 601 having one input connected to line BUSYT' and a second input connected to the output of OR- circuit 602. The inputs of OR-circuit 602 are connected, respectively, to the output of AND-circuit 603, the output of AND-circuit 604, the GCRl signal line and the GCRZ signal line.

The inputs of AND-circuit 603 are connected to the SPACE, LOOK and CYCLC signal lines so that a carrier return can be initiated when a space byte is available during the right margine routine. The inputs of AND-circuit 604 are connected to the PROCS and CR signal lines so that a carrier return can be initiated whenever a carrier return byte is available.

The output I of edge triggered flip-flop 605 is connected to line GCRl while the data input D thereof is connected to the output of AND-circuit 606. The inputs of AND-circuit 606 are connected to lines LOOK and HYPHEN so that a carrier return can be initiated when a hyphen byte is available during the right margin routine. The BUSYT signal is fed to the clock terminal C of flip-flop 605.

The output of flip-flop 606 is connected to line GCR2. The data input D of flip-flop 606 is connected to the output of AND-circuit 607 whose inputs are connected to lines DCR and KCR and the output of flipflop 606 to initiate the second carrier return when double line advance is called for. The BUSYT signal is fed to clock terminal C of flip-flop 606.

The second circuit of operational magnet drivers 22 centers around logic network 608 which generates the BKMAG, SPMAG, PROCS, LCMAG, UCMAG, GSLSH and GUL signals. The logic network 608 is an array of AN D-circuits, OR-circuits and inverters which perform the following Boolean operations:

I. BKMAG CYCLB BUSYT' BKSP PROCS 2. SPMAG PROCS SPACE 3. LCMAG [BUSYT'] (BKLCH 4. UCMAG [BUSYT] (C'kLCll 5. GSLSH BKLC-BUSYT 6. GUL C'KLC'BUSYT [(AGREE"A'LSB) -7. PROCS AAGREE'BUSYT' 8. AGREE (FUNC) (KLC-LSB) (KLC'LSB') 9. PFRST (SLAP'UPPER'LSB') (PAUL LOWER-LS3) ID. A [PFRST'CYCLA] [CYCLC" GCYCLS'PFRST'] [GCYCLS-CYCLC'(CONT-SPACE)"(SPACE" LOOK)'] l l. B (PFRST'CYCLCSLAPJ (PFRST"CYCLA" SLAP) 12. C (PFRST-CYCLC'PAUL) (PFRST'CYCLA PAUL) (CYCLC-LOOKCONTSPACEJ.

where a implies an ORTunction which can be performed by an OR-circuit. a implies an AND- function which can be performed by an AND-circuit and implies a NOT-function which can be performed by an inverter.

The UPPER and LOWER signals are generated by the outputs 0 and 1, respectively of set/reset flip-flop 609. The set input 8 of flip-flop 609 is connected to the output of AND-circuit 610 whose inputs are connected to the KLC and DOB signal lines while the reset input R of flip-flop 609 is connected to the KLC' and DOB signal lines. Note inverter 612 shows how the KLC signal is inverted to obtain the KLC' signal.

The margin control 24 (an examining means) shown in FIG. 7 comprises seven

identical decoders

701, 702, 703, 704, 705, 706 and 707 having inputs connected via cabls SR1, SR2, SR3, SR4, SR5, SR6 and SR7, respectively, to the outputs of the first, second, third, fourth, fifth. sixth and seventh stages, respectively of shift register 12. A typical decoder 701 senses for the coded combination of bits associated with either a space, a carrier return or a hyphen byte (a possible end of line byte) and transmits a signal from its output upon such sensing. The outputs of all the decoders are connected to inputs of OR-circuit 708 whose output is connected via inverter 709 and line 710 to an input of AND- eircuit 711. Thus, line 710 will be low whenever a possible end ofline byte is in shift register 12 (FIG. 1) otherwise the line will be high.

A second input of AND-circuit 711 is connected to line LOOK which is connected to the output 1 of edgetriggered flip-flop 712 whose other output 0 is connected to line LOOK. The data input D of the flip-flop is connected to the MARGlN line and the clock input C of the flip-flop is connected to the output of OR- circuit 713 having inputs connected to the AUTO and KCR lines. The CHARF signal line is connected to the third input of AND-circuit 711 whose output is connected to the STOPA signal line and via line 714 to the STOPA signal line. Generally, a MARGIN signal sets flip-flop 712 to generate the LOOK signal which samples AND-circuit 711. If line 710 is low nothing further happens until there is a carrier return with the KCR signal clearing flip-flop 712. lfline 710 is high the STOPA signal is generated stopping automatic operation and the operator must go onto manual operation. When the operator depresses the one character switch OCSW (FIG. 3) for the first time the CHARF' signal disappears blocking AND-circuit 711 and terminating STOPA signal. When the operator thereafter depresses the auto switch ASW (FIG. 3) to restart automatic operation, the AUTO signal clears flip-flop 712 or if the operator manually inserts a carrier return the KCR signal will clear the flip-flop 712.

Thus, there has been shown a record medium controlled typewriter system. While the record medium was described as a magnetic tape in a cassette type tape recorder, other record media such as magnetic cards, punched paper tapes, punched cards or even computer or data terminal sources could be used.

In the claims certain terminology will be used. A graphic is intended to mean an alphabetic character, a numeric character or a symbol. By print formatting movements is meant carrier returns, hyphenating or spacing. Print positioning movement means positioning the printing device (the carrier) with respect to the record medium. Start of line print positioning movement means moving the printing device to the left margin plus a single line advance, i.e., a carrier return and line advance.

What is claimed is:

1. In combination with a typewriter which can print graphics in response to combination of electric signals and can perform both start of line and other print formatting movements in response to particular electrical signalings, apparatus for controlling the typewriter to controllably perform a start of line positioning movement comprising alerting means for generating an initiate start of line print positioning movement signal when the actual print position of the typewriter is beyond a given distance from the start of line print position, means for storing coded combinations of bits representing graphics to be printed and print formatting movements to be performed wherein a first particular coded combination of bits is associated with a print formatting movement, reading means for sequentially reading in a desired order the coded combinations of bits stored in said storing means, means for converting the read coded combinations of bits to coded combinations of signals and electrical signalings for transmission to the typewriter, examining means connected to said alerting means for simultaneously examining a given number of sequential coded combinations of bits in said storing means which will be converted subsequent to the occurrence of an initiate start ofline print positioning movement signal to determine whether any one of said given number of sequential coded combination of bits includes said first particular coded combination of bits, means connected to said examining means for stopping said reading means when said examining means indicates the absence of said first particular coded combination of bits in the group of cxam ined coded combination of bits, and first particular electrical signal generating means for transmitting the particular electrical signaling to the typewriter to perform a start of line positioning movement when said first particular coded combination of bits representing a start of line positioning movement is read from said storing means after the generation of an initiate start of line print positioning movement signal.

2. The combination of claim 1 further comprising means settable by further particular coded combinations of bits read from said storing means for controlling the number of particular electrical signalings transmitted to the typewriter each time said first particular I electrical signal generating means is activated.

3. in combination with a typewriter which can print graphics in response to combinations of electric signals and can perform start of line print positioning movements in response to a particular electrical signaling, apparatus for controlling the typewriter to perform automatically different numbers of start of line print positioning movements comprising means for storing coded combinations of bits wherein the coded combination of bits represents graphics to be printed while a first particular coded combination of bits represents a single start of line print positioning movement and a second particular coded combination of bits represents a multiple start of line print positioning movement, means for sequentially reading in a desired order the coded combinations of bits stored in said storing means, means for converting those coded combinations of bits representing graphics to be printed to combinations of electrical signals for transmission to the typewriter to cause the printing of graphics, line advance means for receiving said first and second particular coded combinations of bits and storing only an indication of the last received thereof at any given time, means for generating an initiate start of line print positioning movement signal including means responsive to a third particular coded combination of bits read from said storing means. and means receiving said initiate start of line print positioning movement signal for transmitting a number of said particular electrical signalings to the typewriter, said number being determined by the indication stored in said line advance means.

4. The combination of claim 3 further comprising an other means for generating an initiate start of line print positioning movement signal when the number of symbols printed by the typewriter since the previous start of line print position movement by the typewriter is within a given range.

5. The combination of claim 3 further comprising another means for generating an initiate start of line print positioning movement signal when the actual print positiong of the typewriter is beyond a given distance from the start of line print position.

6. The combination of claim 3 wherein the means for generating an initiate start of line print positioning movement signal includes alerting means for generating such signal when the actual print position of the typewriter is beyond a given distance from the start of line print position.

7. The combination of claim 6 wherein said storing means stores third particular coded combinations of bits associated with print position formatting, and further comprising examining means connected to said alerting means for examining a given number of sequential coded combinations of bits in said storing means which will be converted subsequent to the occurrence of an initiate start of line print positioning movement signal to determine whether any one of said given number of sequential coded combination of bits includes said first particular coded combination of bits, means connected to said examining means for stopping said reading means when said examining means indicates the absence of said third particular coded combination of bits in the group of examined coded combination of bits, and first particular electrical signal generating means connected to said examining means for transmitting the particular electrical signaling to the typewriter to perform a start of line positioning movement after said third particular coded combination of bits is read from said storing means.

8. In combination with a typewriter which can print graphics in response to combinations ofelectric signals, and which can backspace in response to a first particular electrical signaling, apparatus for controlling the typewriter to print composite graphics having one fixed element and one variable element comprising means for storing coded combinations of bits representing the variable elements to be printed, a first particular coded combination of bits representing a start of composite printing indicator, and a second particular coded combination of bits representing an end of composite printing indicator, means for sequentially reading in a desired order the coded combinations of bits stored in said storing means, first controllable means for converting those coded combinations representing the variable elements to combinations of electric signals for transmission to the typewriter to cause the printing of variable elements, second controllable means for generating the combination of electrical signals representing the fixed element for transmission to the typewriter for printing the fixed element, a controlled signal generator for generating said first particular electrical signaling for transmission to the typewriter for backspacing, control means having a first state for controlling only said first controllable means to operate once each time a coded combination of bits representing a variable element is read, said control means having a second state for controlling one of said controllable means, said controlled signal generator and the other of said controllable means to operate sequentially in that order each time a coded combination of bits representing a variable element is read, means, operative during the sequential reading of the coded combination of bits stored in said storing means, for sensing for said first particular coded combination of bits for setting said control means to said first state, and means, operative during the sequential reading of the coded combination of bits stored in said storing means, for sensing for said second particular coded combination of bits for setting said control means to said second state.

9. The combination of claim 8 wherein the typewriter is also switchable between upper and lower case positions in response to second particular signalings and generates a case position indicating signal in accor dance with its instantaneous case position and said combination further comprising first indicating means indicating the case ofthe fixed element. second indicating means indicating the case of the variable element to be printed, second control means connected to said first and second indicating means and receiving the case position indicating signal from the typewriter and operable when said first control means is in said second state to select which controllable means operates first in said sequence.

10. The combination of claim 9 wherein said second control means includes energizing means for first energizing the controllable means associated with the ele ment whose case is the same as the case position ofthe typewriter when the cases of the fixed and variable ele ments are different.

11. The combination of claim 10 further comprising means for transmitting said second particular signalings to the typewriter to cause a switch in the case position after the operation of said energizing means.

12. The combination of claim 8 wherein the typewriter can perform a space movement in response to a second particular electrical signaling and further comprising means for controlling the printing of said fixed element in conjunction with the performance of a space movement by the typewriter.

13. In combination with a typewriter which can print graphics in response to combinations ofelectric signals, which is switchable between upper and lower case positions in response to first particular electrical signalings and which can backspace in response to second particular electrical signaling, and which generates a case position indicating signal in accordance with its instantaneous case position, apparatus for controlling the typewriter to print composite graphics having one fixed element with a predetermined case and one variable element having either of the two cases comprising first means for indicating a composite graphic to be printed, second means for generating the coded combination of signals representing the fixed element, third means for generating the coded combination of signals representing the variable element, first indicating means indicating the case of the fixed element, second indicating means indicating the case of the variable element, first control means connected to said first and second indicating means and receiving the case position indicating signal from the typewriter for first transferring to the typewriter the coded combination of signals representing that element whose case is the same as the case position of the typewriter when the cases of the two elements are different, and second control means operative thereafter to control the typewriter to overprint the other of the two elements.

14. The combination of claim 13 wherein said second control means comprises third control means. operative after the operation of said first control means, for controlling the transmission of said first and second particular signalings to cause the typewriter and backspace and switch case positions, and fourth control means, operative after the operation of said third control means, for controlling the transfer of the coded combination of signals representing the other element to the typewriter.

15. in combination with a typewriter which can print graphics in response to combination of electric signals and can perform both start of line and other print formatting movements in response to particular electrical signalings, apparatus for controlling the typewriter to controllably perform a start of line positioning movement comprising alerting means for generating an initiate start of line print positioning movement signal when the actual print position of the typewriter is beyond a given distance from the start ofline print position, storing means for storing coded combinations of bits representing graphics to be printed and print formatting movements to be performed wherein a group of first particular coded combinations of bits are associated with a print formatting movement, said storing means including a buffer storing means for storing a plurality of said coded combinations of bits, reading means for sequentially reading in a desired order the coded combinations of bits stored in said buffer storing means, means for converting the read coded combinations of bits to coded combinations of signal and electrical signalings for transmission to the typewriter, examining means connected to said alerting means for examining the sequential coded combinations of bits in said buffer storing means which will be converted subsequent to the occurrence of an initiate start of line print positioning movement signal to determine whether any one of said given number of sequential coded combination of bits includes one of said first particular coded combination of bits, means connected to said examining means for stopping said reading means when said examining means indicates the absence of one of said first particular coded combinations of bits in the examined coded combination of bits in said buffer storing means, and first particular electrical signal generating means connected to said examining means for transmitting the particular electrical signaling to the typewriter to per form a start of line positioning movement when one of said first particular coded combination of bits is read from said storing means after the generation ofan initiate start of line print positioning movement signal.

16. The combination of claim 15 wherein one of said first particular coded combination of bits represents a space positioning movement.

17. The combination of claim 15 wherein one of said first particular coded combination of bits represents a hyphen symbol to be printed by the typewriter.

18. The combination of claim 15 further comprising means settable by further particular coded combinations of bits read from said storing means for controlling the number of particular electrical signalings transmitted to the typewriter each time said first particular electrical signal generating means is activated.

Claims

1. In combination with a typewriter which can print graphics in response to combination of electric signals and can perform both start of line and other print formatting movements in response to particular electrical signalings, apparatus for controlling the typewriter to controllably perform a start of line positioning movement comprising alerting means for generating an initiate start of line print positioning movement signal when the actual print position of the typewriter is beyond a given distance from the start of line print position, means for storing coded combinations of bits representing graphics to be printed and print formatting movements to be performed wherein a first particular coded combination of bits is associated with a print formatting movement, reading means for sequentially reading in a desired order the coded combinations of bits stored in said storing means, means for converting the read coded combinations of bits to coded combinations of signals and electrical signalings for transmission to the typewriter, examining means connected to said alerting means for simultaneously examining a given number of sequential coded combinations of bits in said storing means which will be converted subsequent to the occurrence of an initiate start of line print positioning movement signal to determine whether any one of said given number of sequential coded combination of bits includes said first particular coded combination of bits, means connected to said examining means for stopping said reading means when said examining means indicates the absence of said first particular coded combination of bits in the group of examined coded combination of bits, and first particular electrical signal generating means for transmitting the particular electrical signaling to the typewriter to perform a start of line positioning movement when said first particular coded combination of bits representing a start of line positioning movement is read from said storing means after the generation of an initiate start of line print positioning movement signal.

2. The combination of claim 1 further comprising means settable by further particular coded combinations of bits read from said storing means for controlling the number of particular electrical signalings transmitted to the typewriter each time said first particular electrical signal generating means is activated.

3. In combination with a typewriter which can print graphics in response to combinations of electric signals and can perform start of line print positioning movements in response to a particular electrical signaling, apparatus for controlling the typewriter to perform automatically different numbers of start of line print positioning movements comprising means for storing coded combinations of bits wherein the coded combination of bits represents graphics to be printed while a first particular coded combination of bits represents a single start of line print positioning movement and a second particular coded combination of bits represents a multiple start of line print positioning movement, means for sequentially reading in a desired order the coded combinations of bits stored in said storing means, means for converting those coded combinations of bits representing graphics to be printed to combinations of electrical signals for transmission to the typewriter to cause the printing of graphics, line advance means for receiving said first and second particular coded combinations of bits and storing only an indication of the last received thereof at any given time, means for generating an initiate start of line print positioning movement signal including means responsive to a third particular coDed combination of bits read from said storing means, and means receiving said initiate start of line print positioning movement signal for transmitting a number of said particular electrical signalings to the typewriter, said number being determined by the indication stored in said line advance means.

4. The combination of claim 3 further comprising another means for generating an initiate start of line print positioning movement signal when the number of symbols printed by the typewriter since the previous start of line print position movement by the typewriter is within a given range.

8. In combination with a typewriter which can print graphics in response to combinations of electric signals, and which can backspace in response to a first particular electrical signaling, apparatus for controlling the typewriter to print composite graphics having one fixed element and one variable element comprising means for storing coded combinations of bits representing the variable elements to be printed, a first particular coded combination of bits representing a start of composite printing indicator, and a second particular coded combination of bits representing an end of composite printing indicator, means for sequentially reading in a desired order the coded combinations of bits stored in said storing means, first controllable means for converting those coded combinations representing the variable elements to combinations of electric signals for transmission to the typewriter to cause the printing of variable elements, second controllable means for generating the combination of electrical signals representing the fixed element for transmission to the typewriter for printing the fixed element, a controlled signal generator for generating said first particular electrical signaling for transmission to the typewriter for backspacing, control means having a first state for controlling only said first controllable means to operate once each time a coded combination of bits representing a variable element is read, said control means having a second state for controlling one of said controllable means, said controlled signal generator and the other of said controllable means to operate sequentially in that order each time a coded combination of bits representing a variable element is read, means, operative during the sequential reading of the coded combinatioN of bits stored in said storing means, for sensing for said first particular coded combination of bits for setting said control means to said first state, and means, operative during the sequential reading of the coded combination of bits stored in said storing means, for sensing for said second particular coded combination of bits for setting said control means to said second state.

9. The combination of claim 8 wherein the typewriter is also switchable between upper and lower case positions in response to second particular signalings and generates a case position indicating signal in accordance with its instantaneous case position and said combination further comprising first indicating means indicating the case of the fixed element, second indicating means indicating the case of the variable element to be printed, second control means connected to said first and second indicating means and receiving the case position indicating signal from the typewriter and operable when said first control means is in said second state to select which controllable means operates first in said sequence.

10. The combination of claim 9 wherein said second control means includes energizing means for first energizing the controllable means associated with the element whose case is the same as the case position of the typewriter when the cases of the fixed and variable elements are different.

13. In combination with a typewriter which can print graphics in response to combinations of electric signals, which is switchable between upper and lower case positions in response to first particular electrical signalings and which can backspace in response to second particular electrical signaling, and which generates a case position indicating signal in accordance with its instantaneous case position, apparatus for controlling the typewriter to print composite graphics having one fixed element with a predetermined case and one variable element having either of the two cases comprising first means for indicating a composite graphic to be printed, second means for generating the coded combination of signals representing the fixed element, third means for generating the coded combination of signals representing the variable element, first indicating means indicating the case of the fixed element, second indicating means indicating the case of the variable element, first control means connected to said first and second indicating means and receiving the case position indicating signal from the typewriter for first transferring to the typewriter the coded combination of signals representing that element whose case is the same as the case position of the typewriter when the cases of the two elements are different, and second control means operative thereafter to control the typewriter to overprint the other of the two elements.

14. The combination of claim 13 wherein said second control means comprises third control means, operative after the operation of said first control means, for controlling the transmission of said first and second particular signalings to cause the typewriter and backspace and switch case positions, and fourth control means, operative after the operation of said third control means, for controlling the transfer of the coded combination of signals representing the other element to the typewriter.

15. In combination with a typewriter which can print graphics in response to combination of electric signals and can perform both start of line and other print formattIng movements in response to particular electrical signalings, apparatus for controlling the typewriter to controllably perform a start of line positioning movement comprising alerting means for generating an initiate start of line print positioning movement signal when the actual print position of the typewriter is beyond a given distance from the start of line print position, storing means for storing coded combinations of bits representing graphics to be printed and print formatting movements to be performed wherein a group of first particular coded combinations of bits are associated with a print formatting movement, said storing means including a buffer storing means for storing a plurality of said coded combinations of bits, reading means for sequentially reading in a desired order the coded combinations of bits stored in said buffer storing means, means for converting the read coded combinations of bits to coded combinations of signal and electrical signalings for transmission to the typewriter, examining means connected to said alerting means for examining the sequential coded combinations of bits in said buffer storing means which will be converted subsequent to the occurrence of an initiate start of line print positioning movement signal to determine whether any one of said given number of sequential coded combination of bits includes one of said first particular coded combination of bits, means connected to said examining means for stopping said reading means when said examining means indicates the absence of one of said first particular coded combinations of bits in the examined coded combination of bits in said buffer storing means, and first particular electrical signal generating means connected to said examining means for transmitting the particular electrical signaling to the typewriter to perform a start of line positioning movement when one of said first particular coded combination of bits is read from said storing means after the generation of an initiate start of line print positioning movement signal.