CA1118243A - Method and apparatus for reproducing a musical presentation - Google Patents
Method and apparatus for reproducing a musical presentationInfo
- Publication number
- CA1118243A CA1118243A CA000354537A CA354537A CA1118243A CA 1118243 A CA1118243 A CA 1118243A CA 000354537 A CA000354537 A CA 000354537A CA 354537 A CA354537 A CA 354537A CA 1118243 A CA1118243 A CA 1118243A
- Authority
- CA
- Canada
- Prior art keywords
- data
- musical
- actuation
- transitions
- bits
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Signal Processing For Digital Recording And Reproducing (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
There is disclosed a method and apparatus for reproducing a musical presentation wherein musical data, from such presentation, such as keyboard actuations of a keyboard-type musical instrument, is encoded and stored in a code which has information contained in the transitions only and the sense and direction of such transitions are ignored. This avoids several major drawbacks of bi-phase level code previously disclosed because the (1) phase of the signal need not be maintained, and (2) the bi-phase level code cannot be recovered following a dropout until a 1-0 or a 0-1 transition occurs. There is also disclosed a data dropout detection system for assuring that the wrong music is not played.
There is disclosed a method and apparatus for reproducing a musical presentation wherein musical data, from such presentation, such as keyboard actuations of a keyboard-type musical instrument, is encoded and stored in a code which has information contained in the transitions only and the sense and direction of such transitions are ignored. This avoids several major drawbacks of bi-phase level code previously disclosed because the (1) phase of the signal need not be maintained, and (2) the bi-phase level code cannot be recovered following a dropout until a 1-0 or a 0-1 transition occurs. There is also disclosed a data dropout detection system for assuring that the wrong music is not played.
Description
l'n is illvcnt.ion relclteci to ali apF)aratus for reproducing a nlusical preselltation, and more partlcularly to a device for generaLing a respected series of musical data cells.
This is a cl:ivision of copending Canadian Patent ~pplication Serial No. 276,996, filed ~pr:il 26, 1977.
Automated musical instruments have been known for many years. Automation of keyboard actua~ions has been accomplished in the panio, organ, carillon, ete., when the Iceyboard aetuations are translated to perforations in a paper tape, which constitutes a storage medium~ and then these recorded actuations are used to actuate the instr~lment to produce the music. ~n punched paper memories, such as the player piano or organ, there is typieally one ehannel for each key on the piano or organ keyboard. In the electrifieatlon of sueh instruments, the changeable memories of various types have been used. For example, in Cooper U.S. Patent No.
3,380,026, issued on April 23, 1969, magnetie eore elements are used as memory deviees into whieh are "read" the eondLtion of a plurality of aetuator elements SIICII tlS the stops or eoupler switehes of an organ. 'l'hese storecl aetucltions are "read out" at selected times to reactuate the actuator elements and reproduce the stored mus:ical informatlon. Inexpensive ma~netic tape cassettes are disclosed in the prior art, as in Schmoyer U.S. Patent No. 3,388,716, issued on June 18, 1968, and in Englund U.S. Patent No. 3,604,299, issued on September 14, 1971, both of which disclose multiplex recording of key switeh aetuations, one of whicll is a frequeney multiplexing seheme whereas the other is a time divislon multiplexing scheme.
cbr/
Valio~ rm~; of ellcoclillg systems have been ut~ ed, as, for examp:le, in l'et:ersoM U.S. PaLent No. 3,683,096~ issued on ~ugust 8, 1972, a recllrring frame of pul.ses has one pulse therein for each of the key switches of the musical instrument and a pulse mod;.fier is utili7fd for modifying in a predeter~
mined manner a specif:ic pulse in each frame and these modified pulses are thereafter decoded. In Wheelwright U.S. Patent No. 3,771,406, issued on November 13, 1973, the key switch actuations are encoded into a five bit binary code which is loaded into a shift register for a parallel to a serial con-version; and in Mail.let U.S. Patent No. 3,789,719, issued on February 5, 1974, key switch actuations are loaded directly into a shift register which, for a piano, would have 88 stages, one for each key, and additional ones for the other controls of the unit~ and a key pulse is generated by the last stage of the shift register and these pulses along with the clock pulse are recorded directly upon the tape for subsequent play-back. Finally, in Vincent U.S. Patent No. 3,905,267, issued on September 16, 1975, the keyboard switch actuations are passed through a multiplexer to seriall~e the key switch actuations which are then encodetl in a hi-phase :Level encoder, best shown i.n FIC. 6 and the wavefortns of FIC`. 7 of the U.S.
Patent 3,905,267. The bi-phase level data may be further encoded to provi.de a double density encoding shown in the waveform diagrams of FIG. 9 of U.S. Patent 3,905,267 which is subsequently recorded upon a magnetic tape, played back, decoded and demultiple~ed for subsequent reactuation of the piano keyboard.
With respect to all prior art encoding and decoding cbr/
s{hem~s, tl~(y all Illv~ ;eri()us drawback-: hecause tiley appear to he att:e~l~)ts tc. apply moderrl electronic technology to electrollic player pianos but have failed to really grasp or apply the techno]ogy in such a way as to make it compatible witll tlle p]ayillg back of recorded music. In some prior art systems i the tape recorded is stopped while notes are being played, the last notes p]ayed may be held on which is undesir-able at best and may cause damage to the system Moreover, there are several places that will cause wrong notes to be struck in a musical system. In all cases, striking the wrong note sounds much worse than striking no note at all. The first problem is that wlltn tilC recorder is started, or when the electronics are first powered on, there is no synchronization of the internal electronic counters to the data that is re-covered from the recorder until the first sync code is received.
If this is permitted to happen, it can cause wrong notes to be struck at the beginning of replay. The second problem is of more serious consequence, depending on the code used, because if in the middle of tlle replay the tape has a dropout, the electronics lost- the sync and wrong noteC; are struck. Tn any fast scan mult~ lex syste~ a:ll note-: tl~at are on at the time of the dropout may be shifted either up or down the scale until the sync code is recovered again. Finally, accidental detection of a wrong sync code due to noise, misadjustment of controls or the data information contained in the sync code causes the playing of wrong music because of the improper synchronization.
The present invention resides in an electronic keyboard musica:L instrument having selectively actuatable cbr/
key switch dev:ices, means for scanning the key switch devices and producing sequentia]. frames of time d:ivision multiplexed electrical signals from the musical information represented by the selectively actuated condition of the keys, and a magnetic tape storage medium~ bi-phase encoding means for encoding the time division multip:Lexed signals, and means for recording the bi--phase encoded time divisional multiplexed signals on the magnetic tape storage medium as magnetic flux transitions.
In the present invention means are provided for generating a repeated series of musical data cells, each data cell being delineated from an adjoining musical data cell by a sharp ti.ming signal transition and each data cell carrying a predetermined note according to the actuation or non-actuation of the selectively actuatable key switch devices.
Each time frame contains a serial sequence of musical data cells, there being a ti.ming signal transition at the beginning of each musical data cell and the presence or absence of one additional signal transition proximate the center of each musical data cel.l, respectivel.y, const:i.tlltes the musicl.al information correspondlng to the actuation or non-actuation of the key switches, respectively, so that the predominant number of musical data cells are in a zero format wherein the data stream has the effect of essentially all zeros and no musical notes stored therein if a data dropout occurs. The signal transitions on the magnetic tape are recorded in the form of magnetic flux transitions whereby the timing signal transi.tions and musical actuated key switch information are constituted solely by magnetic flux transitions on the tape, cbr/,' r c. s 1~ ( c t ; v c. 1 ~ .
l~he prc~sellt in~7elltion cllso rcsides in a method of prevent:illg the playillg of erroneo-ls notes due to the transit-ion of digltal clata contai~ing data bits in data cells having a b~g:inning and an ending, the data bits corre-sponding to the act~lation or non-actuation of the contro]s of a musi,cia], instrument. In the method, each musical note is assignec~to a data cel]~ and a ti:ming sigrlal transition is located at the beginning of each data cel]. Between the beginning and ending of the data cel] a signal transition or non-transition is ]ocated in each the cell according to the acl-uation or non-ac~t-lnl-iol-, 'respective]y, of the controls.
Tn tile h;--rllase :leve] cc~ded waveform as disclosed in the Vincent patent, there are two significant drawbacks, the first of which is that the phase of the signal m~lst be maintained by the systen- if it be recorded on tape and~
secondly, if a dropout occ:urs the 1-0 relationship cannot be recovered until a 1-0 or 0-1 transition occurs in the NRZ waveform. What actually occurs in the playing of music is that all Y,eros (nc) IllUS:iC) becomes all onc~s (clll llOI:eS
being played). 'i'lli9 a]sc- occurs clllring the stopping and starting of the recorder.
I have discerned that a number of the prob],ems involved in coding systems for musical performances are that the bi-phase leve], code recluires transition to occur in both positLon ancl sense so that in the playing of music, all Y.eros (no music) become all ones (all -4a-cbr/
notes bein plnycd). `f have determined that tbe problem wlth this eoding ~chcme is that in Lhe recording of keybcard music, the lnfor-Dlation ls higllly weiE?lLed with ~eros ~no key closures) and, therefore, in aecordAnce wlth the invention, a code uscd for a slow recorder is sueh that the data (oncC; ar.d ~eros) would look like all ~eros. The bi-phase (or mark) code, as diselosed at page 42 of the Telemetry Standard~ Document 106-71 ( a portJon cf W]liC}! is reproduced in Fig. 2 hereof), has as ~eros inforruation the wide spacing between : transitions. There is always a transieion at the beginning of each bit period which can be recovered as the self-clocking portion of the eode. The information is therefore contained only in the interbit transitions and not in the direction and sense of transition as in the bi-phase level code. ~loreover, the data may be inverted and still be satisfactorily recovered. If a data dropout occurs, the data detector ean immediately regain correct phasing wlthout errors.
The above and other objects, advantages and features of the invention will become more apparent when considered in light of the accompanying drawingc: wherein:
DESCRIPTION OF T}IE DRAWINGS
... .. _ . _ FIG. 1 is a block diagram of an electronie reeord and player system for musical instruments;
FIGS. 2(a), (b) and (c) are n sequence of waveform dia~rams taken from page ~2 of Tolemetry Standards Document 106-71;
FIGS. 3A and 3B, taken together, arc a detailed schematic of the key switch scanning and encoding system incorporating the invention;
FIGS. IIA and 4B, taken together, are a detailed schematic of the playback electronlcs;
FIGS. 5(a-J) are illustrative waveform diagrams with the Z~3 varic)u~ po:ints in l`IC;S. ~A, 3B, 4~ ancl 4~ indicated to thc right:
of eacl~ aveform, for collven:ience, the data bits in each bit period or cell. are shown at the top and bottom of FIG. 5; and FIG. 6(a) is a waveform di.agram of the "D Pulsei' FIGS. 4A and ~B il~ustrating various problems which can occur in the playback of a recorded musical presentation and FIG.
6(b) is a wavefcrm d:iagram of the "blank" pulse corre~sponding thereto.
DETAII.ED DESCRTPrION
There is in ex:istance a service manual entitled "Service ~Ianual for Teledyne Piano Recorder Player Model PP-l Assemb],y Number 3288 ~Tr~ 3263", whi.ch is a publ:ication of the assignee hereof alld is somc!times referred to hereinafter as "Service Manual" and an assembly manual entitled "Assembly Instruction for Teledyne Piano Recorder/Player Model PP-l Assembly NuTnl)er ATIJ-3238 Document Number ATI. 3262, which is a publi.cation of the ass:igllee hereof and sometimes referred to hereinafter as "Installation Manual".
The above-described publications describe in detail a speci.f-ic and preferrecl embc-d~ lent of an e:l.e(:t-ron:;c player p:iano incorporat:ine the :i.nventic)n deE:ined :;,n the claims hereof as made and so].d by the assignee hereof.
~ eferring now to FIG. 1, the keyboard of a piano is desigllatetl by tlle nnmbera]. 10 and ~onstitutes the keyboard-pedal data sourc:e. It could be any musical keyboard source instrument such as a. harl)s:icord, carillon, organ, piano, etc., and each output or switch actuation is indicated by a single line 11-1 throu~h l].-N, tlle number of such output ].ines corre-sponding to the number o~ key switch actuations to be sensed -ancl recorded, for e~amp].e, eighty keys (in one embodiment d:isclosed herei.n~, the "sustain" and "].oud" pedals of . " -6-nn cl~hty--ctgl)t key piano may bc scnsed. A sequlltcc of synchronizing blts from .ync gcTIcrator 10-S ls provided on line ll-S. A Mul~lplexer 12 (sbowll in cletall ill FIG. 3~ scans or looks at each individual linc ll~ S in a times sequcnce whicll constitutcs fra~cs. Thus, thc key switch, sustaill and loud pedal, ~ctuations are sensed by thc digital n~ultLplexer 12, one at a time, and in gencrally se~uential fashion. However, i~ no transpositions are contcmi)la~ed, lt is not necessary that thcy be sequcntially examincd, it bclng evidcnt from ; the dcscription givcn in connection with FIG. 3 that they may be looked at or scanned in groups and in any Iashion or order, the only criteria being that the position of the particular switch in its scan time bc maintained in thc entirc system. The timin~, source 1' is shown in FIG. 3B, and is dcscrlbcd in thc scction hcreafter entitled "Mlllti-plexing" .
The ulultip]cxcr thercby translates the parallel dataof the kcy switch actuations to a serial data stream along its output line 13. lhis data ;s then encodcd to a bi-phasP spacc (or mark) signal in bi-phase space (or mark) encoder 1~l and then recordcd on a tape in tape recordcr 15. It will be appreciated that tape recorder 15 is convcntional in all material respects and need not be disclosed or described in any dctail hcrein. It caln bc thc same as is disc~osed in any of the prlor nrt paterlt-: rcfcrrcll to carlier hereln for record-ing digital data on tape or as showll in thc included "Service" and "Installation" Manuals~
Such tapes may be recordedbeforehand by known or accomplishcd artists or in home recordLngs, or rcrecordings of punched paper rolls, etc. In the case of rccordin~ made by stars, performers and the like, these rccordings may be sold scparately and apart from the rccordin~ system pcr se. That is to say, a tape may be encoded ~ 7-. - ~ - !
nnd thc strlng-; of a ~f.lno, fnr example, struek or aetuEIted by hnn~mer3 or the likc in exEIcLly the :ame minnTler as An accomplis?led artist woulcl be on 21 piallO Wh:LCh is set up for playhaek operation only in the manner illustra~ed in TIGS. 4A and ~IK hereof. In other words, one need not eguip a piano for the reeord funetlon disclosed herein.
On playlack by tile tape recorder 15, the bi-phase spaee (or mar~) data appeclrs at the output of a read head and is fed througl-eorrecting networks and amplifiers to reeover the di~ital signal.
The data from tlle read head is approximately a sine wave, but the OUtpllt from the amplifier on line 16 is a square wave si~nal. ~ore-over, the signal from the read head h215 encoded tllerein the eloek data whieh must be rt-covered arld used in the clemul~iplexillg operation.
The timc recoveIy, bit dropouL, sync counter, bit alld frame eounter eireuitry is shown in lIGS. 4A and l~B and deseribed in detall in the seetion entitled "lhc Deeoder", which recovcrs the timing si~nals, "The Data Dropout Detector" which detects tlle bit dropout, "Sync Counter" for eounting frames of sync pulses and the demultiplex and lateh circuIt.
The bi-phase space (or mark) decoder circuit 17 deeodes the incoming data on line 16 and applies same to aemultiplexer lS
whieh distributes the data to the apE~roprlate eontrol chanllels in the stora~e and solenoid aetunLclr eireuitC 19.
Th~e playbaek loule, shown in FIGS. 3~ and 3B also decodes the exl)ression blts and provides bass and treble DUtpUts to control the volume of play.
Referrln~ now to FIC. 2, the waveforms of a se~uence of data bits (10110001101) are shown in three different bi-phase eneoding sehe:nes, the flrsc of whieh ls shown in llne A of FIC. 2, namely~ the bi-phase level encode scheme. As diselosed in the above-refereneed Telemetry Publieation, this bi-phEIse level (or split phase Manehester ~ 8--.
Il ~ 180), a "onc" i: rc~plcsentcd by a 10, and a "zero!' ~s representcd by a 01. Th~ls, the :crlsc of the transitiorl as wcll as the posltion thercof rcprc~cnts data. In Lhe bi--p?lase space ~or mark), shown in llne n of ~IG. 2, thcrc is a transition at thc bcgillninE of cvcry bit pcriod. ~lowcvcr, a "onc" ls rcprescntccl by no phase shift, l.e., a zero crossil-g, at thc middle of tor intcrblt) the bit pcriod. On tlle other hand, a "zero" in contrast is representcd by a 180 phase shift (i.e., no transition or zero crossing) at thc midd]e of (interbit) the bit period.
The cxact opposite of the bi-phase space (or mark) is shown in llnc C of EIG. 2 whercin a transition occurs at the bc~inning of cvery biL pcr-L(Icl~irl the case of the bi-phase space encoding scheme, but in this casc, tlle represerltntiolls of the one and the zero is cxactly thc revcrse of that shown for the bi-phasc spacc. Thus, in either thc bi-phase space or the bi-phase mark, the sense of the transition is ignored and conveys no information whatcver and it is the presencc, in the case of the bi-phase mark, or absence, in the case of the bi-phasc space, of a transition which dctermines the data.
In accordance with the preferred practice of the present invention, .the: bi-phase syace or mark encoding, format i-; utl]izccl rincc! in this ca5e, thc preclomillnllt number of d;lta bits L9 Ln thc zcro format so that the data strcclrl look-: essentia]ly like all Y.ero.s and if a data dropout, loss of sync, etc. occur~ the system immediately pick9 Up playing ~eros, e.g. not strlking any notcs. Some texts and literature. may ldentify a bi-phase mark code as bi--phase space and vice versa; and some identify tlle code as "freqllency doublinE" or "pulse width ~RZ
1 ...", e.g. see "Digltal ~lagnetic Tape ~ecording for Computer Applications" by l.G. Sebestyen, Chapman and ~lall, 1973.
~ULTIPI.EXING
RCfCrril~, llC~ to F~(S. 3~ and 3B cnch of thc kcy switches is dcsi gn Itl~d b}~ Lh{ nul!lcral S- 1, S-2 ...S-80, tbcrc bcing cigl,t sucll switches in a mod~llc, cach swltcll having an i-;olation elnd blockin diodc associatl:d thcr-wltll, such diodes belng labelcd CR-l and associntccl with switcll S-l and CR-80 is associatcd with switch S-80, etc. Thcsc key sw;tchcs are mllltil)lcxcd in ten groups of eieht and integratcd circuit selcctor U-1 (cac1l integrated circuit element is fully idcntified in tllc "Scrvicc Manual") sclccts tllem one at a time in sequential order until Cig21t arc selected. The sclector circuit 10 U-l I-as as its inputs cloclc/2, clockt4 and clock/8 inputs from seven stage countcr U-6. Thc input to this counter is the cloek input and it cones from a clock circuit 30. Timer circuit 30 contains a con-vcntional oscillntor wllicll with a two-stage counter on its output stnE~c so that thc ouLput is clock and clock dividcd by two. The clock signals "Cl.}~" are applied as the inputs to terminal 1, a seven stage counter U-6, whicll in cffect is a binary decimal decoder having its coded outputs on its output terminals 3, 4, 5, and 6, respcctively, applied to thc input terminals 20, 21, 22 and 23 of one of sixtccn select circuit U-5. Sclect circuit U-5 has terminals 1-17 and the 20 first ten outputs arc uscd as enable signals on output lines 31-0 through 31-9. Thus, each of the modulcs containing switches S-l -S--80 is enabled or strobed one at a time, Thc clock pulses, clock/2, clockl4, and clockl8 from tcrminnls 9, 11 alld 12 of U-fi arc applied to the input tcrminals 9, 10, and 11 of intcgrated circuit U-l and ln conjunction with the 12-volt .5upply and resistors R-3 - R-10, sequentially sample cach of the switches via their blocking diodcs CK-1 - CR-80. Accordingly, there appears on the output terminal of inteErated circuit U-l, a series of pulses, and in the disclosed embodiment, thcre wlll bc one hundred and twenty-eigilt bit periods ,~ 1/ ~10-` ~,it~ f~ tilrl~ it t:~kc; fc,r ~ p~
tc- acL:iv.~ on:~p~lt c~ m;nal :l7 o~ onl- of sclcct c:;rcu:its U-5.
Tilc h-it assigni}lt~nls are sllowll on Cilart ] al)pcari.ng as pagc 21 of th:is clis(~l.osllre; b:;t po';:i.t:ic)nS ~9-10~ are not used and bit pOS;t:iO~ LG is not u~ed along wi.th b:it positions ]19 and 120.
As shown c>n î:he "bit assignment chart", thc sustclin and soft pedals occupy bit pos:it:i.ons 117 and 11.8 in the frame whereas the bit 105-109 ansl lll-lL5 are ~Ised to activate the bass theme and bass thcme intens:ity levels and the treble theme ~nd treblc intensity controls, respec~t:ively. ~inally, bit positions 121-128 are assigncd to thc synchronizi.ng bits which are generated whell a strobe p-l]se appears on pin ].7 of U-59 the zero at bit posi.tion 127 is a cilc(k b:i.t:.
}~,NC'()I)ING (FI(,S. 3~ ~ 3B) It w:ill bc noted that the output: vf the selection circu:it U-l is in time frames with the data bei.ng in non-return to zero code format-. Thi.s date (F .tG . 5a) is applied as one inp~lt to the cncod:ing circuit. As discussed earlier, in the recording of keyboard m~lsic, the inEormation is highly weighted with zeros, that is, there are no key clos~lres and, Lherefore, according to thi.s invcllt:ioll, thc cod-- l.s ';~tC21 that for a slow rccorder thc data (OIIC`'; all(l 7,erog) WOIIld a.l.l loolc like zeros.
As shown at page ~2 of the Telemetry Standards Doc~lment 106-71, the bi-phase space cocle has as zeros information the w:icle spac:ing l)cl:wecn trallC;i.tions. 'l'he information is contained in the trans:it:ions only and not in the direction or sense of the trans:ition as in thc! b:i--phase level code. Thercfore, the data may be inverted and still be satisfactor:ily recovered. If a dropout occ-lrs, the dilt.a detector immecliately regains phasing wi.tllout crrors as disc:llssed later herc:in. The c:i.rcu;t util:izecl c ~ u to ~l.'llCI~ ` th~` c~di` .iS ';ilO~ in l~I(. 3B a~d has a NAND gate U-4C
whicil receivc; Lhe NR~ dlta frolll t:he ~nultiplexcr circuit 12.
The ~R' dat.l :i.s g.qted in NANl) gate U-4C at ~he clock rate is to generate the JK input~ to fli.p flop IJ-2B. The 2x clock is applied as one input of U--2B and the output of NAND gate U-4C
are applied as illpUtS to produce and generate the bi-phase space/mark data. This data is applied to an output follower circuit (which is not here relevant) and this signal is the signal that is applied to the input terminals of the recorder for shaping and recording upon magnetic tape. See the "Service Manual".
Thus, as the artist plays the music upon the keyboard, the keyboard switches, S-l - S-80~ are closed and are scanned at a selected clock rate. This data i.s then multiplexed by the multiplexing arrangement described earlier herein to provide an NRZ data which is gated in NAND gate U-4C to generate the JK
inputs to flip flot U-2B. The 2x clock from timer 30 (FIG. 5b) clocks the flip f].op and the Q output of U-2B is the bi-phase space code (FIG. 5b) which is tape recorded.
It is, of course, not necessary that the musical data originate with a keyboard, for exaDlple, a punclled paper piano roll can be converted to tape form by a brush-hole sensing arrangement with the brushes scanned as if they were the key switches S-l - S-80.
T~IE DECODRR (FIGS. 4~ & 4B) _ _ _ The decoder is shown in FIG. 4~ & 4B and includes the EDGE detecti.on circuit utili~ing U-2 (of FIG. 4A & 4B), the "D Pulse" monostable U-3, and the decoder using U-18. The four exclusive OR gates of U-2 and the delay generated by capacitor Cl generllte a narrow spi.ke called EDGE as shown in FIGS. 4A & 4B.
cbr~J G
~8~9k3 ol-r~ to l::L(,. ~A~ n a ~,~ro ~is pr~s~nt: at pi.n ~ of U-2C, p;n 8 ~ o~of wi]l bc ll:igll WhiCil p1accs a higll ~t pin 2 of U- 2A an~l it ~i o~ltpUt p:in 3 will go higl - 1 2 a -cb r /) '~
~L~18~43 delayed by cap.lcitor Cl. This is applied to pin 13 of U-~ so that pin ll thereof will go low and a pin 6 of U-2B
goes high. At the next transition (the small "b" shown in the waveform diagram leading into pin 9 of U-2C) pin 5 of U-2B will go low and pin 4 remains high momentarily so that a negative going pulse appears at pin 6 of U-~B. Each time a transit:ion occurs another pulse is produced. These pulses are supplied to pin 5 of the monostable multivibrator U-3 and each time pin 5 of the multivibrator goes from zero to high, the OtltpUt pin of the multivibrator will go high. The multivibrator U-3 begins to time out when set by RC resistors 46, 47 and capacitor ~15. The time out ls set to be three quarter bit time. Once U-3 has timed out, pin 6 of the multi-vibrator U 3 returns to zero ready to be re-set. Multi-vibrator U-3 then produces one output for each bit.
DATA DROPOUT DETECTOR
As described earlier, and Witll reference to Fig. 6, if a dropout of data occurs in the tape recording, there can be a loss of sync which causes wrong notes to be struck during the frame of data in which the dropout occurs and this can be quite di-;concertLng to the llstencr. The same disconcerting p]aying of notes can occur if the tape recorder is stopped while notes are being played. The objective of this portion of applicant's invention, which is also described and is claimed in above-identified parent application Serial 276,996, is to sense or detect the dropout of data so as to prevent the playing of undesirable notes and/or avoid damage to the system. The circuit portion of FIGS. 4A & 4~ which is most significant for this aspect of this invention is block cbr/'~i 3X~3 11-4 whi~ is tlli retl-:ig~el-al)le data detector. The output oL re~tri~er~ble nlonocitclble mlllt:ivibrator circuiL U-~stays h~ as in(l;cated :in the waverorm diagrlm from the output: terminal 9 for a time determ:ined by the values of feedback cap<lc-itor -13a-cbr/
~3 arl~l r~;istol 39. A ~liod~ 38I) :is tlsed io d:i.~ch~rg~ the capacitor 3~. In t~le beginll:irlg, p~l:l.scs arc apl)lied from the taye recorder output c:i.rc~l:l.t:, wh:ich are alllplified by transistvrs Ql and Q2 and their associated resisto~ nctworks and applied as an input to optical couple 1l-1. This optical coupling circuit U-l is conventiDnal, having as an output thcreof a square wave whicll is applied as an input to transistor amplif~er 40.
The outpu~ of transistor amplifi.er 40 is the bi-phase space encoded data. The edges tr:igger the non-retriggerable mono-stab].e multivibrator U-3 and the length of time the Q output of this multivi'brator is hi.gh is determined by capacitor 45 and resistors 46 and 47, resistor 46 be:ing adJusted so tllat tlle D pulse output is three quarters thc bit time oL thc :information. I~lth the bi-phase space/mark code described above, when the first ~ero of the data occurs, the monostable begins to trigger on the edge that exists at the end of the bit cell. As noted earlier, there :is a transition at the beginning of every bit period which is the same as the end of the bit cell for the succeeding period. The edge that occurs, due to a one on the middle oE the'bit cell is ignored due to the timing and delay which comes abDut from the adjtlstmentc; oE the ctlpac:Ltol-s and resistors descrLbed abovc. Thc edge ls then ut-.Lli~ed to clock the CI.K or clock input to D flip flop U-18, and the D pulse is applied to the D input of edge detector U-18, with the Q output thereof shown in FIG. 5. The negative cdge of the D pulse is used to store the output of U-18 :into the i.nput register oE the eight bit input rcgi.ster U-l9. The NRZ data is recovered as shown in FIG. 5. The NRZ data at thc Q output of U-18 may be supplied to a shift register (not shown) for transposition purposes, if desired.
Rcfcrr:Lng now to the retriggerable monostable mult:i-j]./ -14-vibrn~or 1l--4, as lonE as thc positivz gOillg cdg{s occur ln less thn predetcrmi,lcd ttmc, thc ~nonostaz)le is rcsct and beEins timing ou~
again. If, due ~c> a slow tapc speed, data dropout or rccordcr stopping, or no lnformaeion bcing recordcd oll the tapc, e.g., a blan~ tapc, no ed~,e occurs in thc 1) pulsc input of rctriggcrablc data detector U~4 and thc dcvice timcs out and clearc: thc sync countcr constieuted by integratcd circuits 1l-10~ and U-lOB and the input reglster both of which prevent notes from being struck or hcld in zl closed statc.
The tlming shown in FIG. 6 is adJustcd to just lon~er than the expected time between the positive going edgc of the ~ pu15c. If the edge docs not occur during the expcctcd time, thc output drops and clcars the sys tcm.
T~ YNt,_COU~'rl~.R
As discu-i<;ed carlier (FIG. 4A 6 4B), if there is a loss of synchronization, wrong notes can be struck by the musical instru-ment which can be quite disconcerting. The prior systems sensed these sync codes and automatically reset. In accordancc with the present inventioz- to insurc that at power on, and at the start of a tape recorder or after a data dropout on the tape, no wrong notes are struck, a sync countcr has been utilized to count three sync codes before allowing any notc to be struck (these would be the thrce sync sequenccs in thc bit assignmcnt chzlrt at blt posltiolls 121-128). Thi.q countcr is rcsct by thc output data dctector circuit U-t~ line i~8 ~labeled "Bl.ln~'l) that dctects if there is data dropout on the tape or the Lape rccorder is running at the wrong speed or that the power has Just been turncd on. This sync counter, constituted basically by intcgrated JK flip flop clrcuits U-lOA and U-lOB, also allows for the po5sibility that thc aync codc could possibly occur randomly ln the data information and rcJects the false sync.
Jl/ -15-~ ( r~tr;~ cl.lJ,'~ da~ cletect(-r circ~it U~ h~s a IJ~III< o~t~ t w~ ich ~ S ~h( COUII~CI- to a 7.ero courlt if tilere is not a~ly data bl~i[lg rcce3v~(l, at po~c~r on, if ~ tape dropout occur~;
or if tape sl~ee~l varia~iolls exist. IE the ~ output of U-lOA or ~-lOB is ~ero, U--llR N~N~! gate i9 higll, a register clear pulse clears all output reg:isters to thereby preveilt any key.s (notes~ from being played. Therefore, ull~il both JK flip 10ps U--lOA and U-lOB outputs are high (one) there cannot be any notes played or struck. NAND
gate U-13A output ]oad)' holds the b~t counters U-l~i and U-15 to all ones count, wh:ich, in turn, is detected by NA~I) gate U-9. When the incoming data from U-18 is sh-ifted through the eight b:it input register U-19, and contaills no sync code, the NAND gate U-6 detects same and sync dettct outl)llt become~s low. When the o~ltpUtS of NANI) gates U-6 and IJ-9 are low ag well as the Q output of JK flip rlop U-lOB and the data detector (Q of U-4~ :is high, the next pulse (the D pulse at Q of U-3) is coupled through resistor R-ll and diode CR-2 and delayed by capacitor 38 and clocks U-lOA arld U-lOR as well as clocking the bit counter wh:ich has been released by U-13A load 27 output.
At this time, the J and K OUtplltS of f]Lp f:Lop U-lOA
are zero and the J and K OUtp~ltS oF U-lOIi are one clud the CL~ changes U-lOB Q to a one alld inverted Q to a zero. The b:it eounter U-14, U-15 eontinues to count until it counts 128 eounts and returns to all ones agaln. If the data is eorrect and the retriggerable data dc-tector U-~ b~ank output Stclys high, the sync code is again in the eight bit regLster U-19. IJ~G and U-9 detect the sync tirne again together wh:ich allows U-lOA J to go to a one and the U-lOA K to zero, wliile U-lOB J and K go to one When the U-lOA and U-lOR are clock, they both change states so as U-lOA ~ is one and U-lOR is zero.
jl/ -16-lhe re~istcr el~ar (~c~. Clr) sl~ tnys high and ~he key~ are stlll not 3110wed to play. After ]28 more counts, U-lOB J is high nnd upon clocking, U-lOB Q becomes a one and the reglster clear becomes a ~ero, thus a110wing the notes to bc struck. In es6ence, then, the system require~. two eomplete rames of 128 bits before any notes may be struck after any disturbance eausfn~ the data detectc)r or sync detecc NAND gnte to indic~te a malfunction. As indicated earlier, the eounting of two frames of syne pulses is illustrated in the context oE Vincent patent 3,905,267.
DEMULTIYLEX AND LATCII
The bit eounters U-14 and U-]5 along with the 8 bit input re~,ister U-l~ demultiplex th~ serial data stream from the Q
output terminnl of U-18. Eaeh sueeecclinr7 bit is sequentially shifted into shift rcgister U-19, and then transferred to lateh eireuits L-l, 1,-2...L-N corresponding to the number of modules (10 in this ease) eontaining key switehes S-l - S-80. Bit eounter outputs CR-8, CTR-16, CTR-32 and CTR-64 are supplied to 4 line to 16 line eonverter U-5 so that upon tlle output ]ines thereof appear, in sequenee, enabling pulses for eaeh of the lateh elreuits L. Bit eounter outputs CTR-l, CTR-2, CTR-4 are the unit select inputs to expression and pedal lateh eireuits EYI.-l and EYI,-2 ~U-20 and U-21).
As Ishown in Flg. 4B C~Ch l.atch elreuLt I,l, L2...1.N
reeeives the data bits on tneir re6peetive data Input terminals D
~terminal 13) frolll the 8-bit input register U19 (FIG. 4A) whieh delays the data one bit time. The data is supplied serially in the storage unlts of the laten eireuits Ll, 1.2...LN. As the data is sent, eounters U14-U15 (FIG. 4B) and the 4-line to 16-line eonverter (U5 of Fig. 4B).
storage plaee in the latch eircuits for eaeh bit. Thus, the eounter 1, eounter 2, and eounter 4 output bits (CTRl, CTR2, and CTR4) ~ 17-detern~ne whicII !~I.ac.e a bit is to be stored in a grc)l-p of eig2lt so that as eaeh latch circuit ls ellal.le.d~ the data bits issuLnE from the 8-bit input register, delayed one bit at a time, are stored in the lateh circuits with the outputs of the 4-line to 16-line eonverter (U5 of Fig. 4B). A total of 16 ~,roups times 8 per group whieh rnakes 128 ehannels with the first group bein~, seleeted by the one output terminal of U5 nnd aEi indieate(l in Fig. 4B (see paragraph 3.5.6 "Data Transfer" of the Teledyne Serviee ~Ianual).
Thus-, eaeh of the lateh eircuits L stores the musical lo information eont<~ined in a data eell of the 128 bit time frame.
Driver trane.i.~tor AND gates DG, one for each key on the keyboard reeeive as on~ i.nput a r.lgnal .Erom the ].atch or storage eireuits l The second input to the dri.vertransistor AND gate DG is a sequence of pulses which are width modulat~d aeeording to the information stored in e~pression and pedal control latch eircui.ts NI'I
EXPRESSTON
A low frequency (200 ~I~) oscillator 70 supplied pulses to a pair of pulse width modulatable one 57l0t monostable multivi-brators 71 and 72 for the bass and treble keys, respeetively. The pulses from oscillator 70 have their mi.~ um w:idth set by a variable resi~tor 73 which thus setE the mi.n:imulll wiclLh of thc pulses from multivibrator~ 71 and 72. Each multivibrator 71 and 72 has its timing set by capacitors 74 and 75, respectively, in eonJunetion with resistors 76-80 for bass theme and resistors 81-85 for the treble theme. Combinat:Lons of resistors 76-80 and eombinations oE
resIstors 81-85 are seleeted by the information eontained in eounter bits CTR-l - CTR-4 which have been stored in expression and pedal eontrol latch eireuits U-20 and U-21, whieh are enabled by two sueeessive outputs (line 13 and line 14) from the four line to sixteen line converter U-5. This stores the treble and bass ~re: -` 1~18243 e,xpression bits in latch circuits EPL-l and EPL-2 along with the soft and sustain pedal controls. It will be noted thAt the latter are also prevented from being actuated on data dropout, loss of sync, etc. by a "Register Clear" signal at U-17B and U-17D. The stored bits are used to vary the number of resistors R76-R80 and R81-R-85 (which are essentially binary weighted) in circuit with timing capacitors 74 and 75, respectively, to thereby vary the charging rate of the capacitors according to the combination of resistors which have been in effect, connected in circuit with capacitor (74 or 75), to thereby vary the width of the pulses established by U-22A for bass effects and U-22B for treble effects.
I ` ~8;~43 The bass efect pulse width pulses are supplied to the group of driver transistor AND gates DG-B for the bass notes solenoid control as the second input thereto and the treble effect pulse width modulated pulses are supplied to the driver transistor 5 AND gatesDG-T for the treble note solenoid control transistors.
If the sync pulse sequence is detected and there has bee no loss of sync, data dropout, etc. as described above, the musical notes stored in the latch circuits are played.
' It will now be seen how the invention accomplishes its various objects and the various advantages of the invention will likewise be apparent. While theinvention has been described and illustrated herein by reference to certain preferred embodiments, it is to be understood that various changes and modifications may be made in the invention by those skilled in the art, without departing from the inventive concept, the scope of which is to beA
determined by the appended Flaims.
. , ',,.
BIT ASSIGN,'~ENT
1. CBlC 44. Glt 87. B32
This is a cl:ivision of copending Canadian Patent ~pplication Serial No. 276,996, filed ~pr:il 26, 1977.
Automated musical instruments have been known for many years. Automation of keyboard actua~ions has been accomplished in the panio, organ, carillon, ete., when the Iceyboard aetuations are translated to perforations in a paper tape, which constitutes a storage medium~ and then these recorded actuations are used to actuate the instr~lment to produce the music. ~n punched paper memories, such as the player piano or organ, there is typieally one ehannel for each key on the piano or organ keyboard. In the electrifieatlon of sueh instruments, the changeable memories of various types have been used. For example, in Cooper U.S. Patent No.
3,380,026, issued on April 23, 1969, magnetie eore elements are used as memory deviees into whieh are "read" the eondLtion of a plurality of aetuator elements SIICII tlS the stops or eoupler switehes of an organ. 'l'hese storecl aetucltions are "read out" at selected times to reactuate the actuator elements and reproduce the stored mus:ical informatlon. Inexpensive ma~netic tape cassettes are disclosed in the prior art, as in Schmoyer U.S. Patent No. 3,388,716, issued on June 18, 1968, and in Englund U.S. Patent No. 3,604,299, issued on September 14, 1971, both of which disclose multiplex recording of key switeh aetuations, one of whicll is a frequeney multiplexing seheme whereas the other is a time divislon multiplexing scheme.
cbr/
Valio~ rm~; of ellcoclillg systems have been ut~ ed, as, for examp:le, in l'et:ersoM U.S. PaLent No. 3,683,096~ issued on ~ugust 8, 1972, a recllrring frame of pul.ses has one pulse therein for each of the key switches of the musical instrument and a pulse mod;.fier is utili7fd for modifying in a predeter~
mined manner a specif:ic pulse in each frame and these modified pulses are thereafter decoded. In Wheelwright U.S. Patent No. 3,771,406, issued on November 13, 1973, the key switch actuations are encoded into a five bit binary code which is loaded into a shift register for a parallel to a serial con-version; and in Mail.let U.S. Patent No. 3,789,719, issued on February 5, 1974, key switch actuations are loaded directly into a shift register which, for a piano, would have 88 stages, one for each key, and additional ones for the other controls of the unit~ and a key pulse is generated by the last stage of the shift register and these pulses along with the clock pulse are recorded directly upon the tape for subsequent play-back. Finally, in Vincent U.S. Patent No. 3,905,267, issued on September 16, 1975, the keyboard switch actuations are passed through a multiplexer to seriall~e the key switch actuations which are then encodetl in a hi-phase :Level encoder, best shown i.n FIC. 6 and the wavefortns of FIC`. 7 of the U.S.
Patent 3,905,267. The bi-phase level data may be further encoded to provi.de a double density encoding shown in the waveform diagrams of FIG. 9 of U.S. Patent 3,905,267 which is subsequently recorded upon a magnetic tape, played back, decoded and demultiple~ed for subsequent reactuation of the piano keyboard.
With respect to all prior art encoding and decoding cbr/
s{hem~s, tl~(y all Illv~ ;eri()us drawback-: hecause tiley appear to he att:e~l~)ts tc. apply moderrl electronic technology to electrollic player pianos but have failed to really grasp or apply the techno]ogy in such a way as to make it compatible witll tlle p]ayillg back of recorded music. In some prior art systems i the tape recorded is stopped while notes are being played, the last notes p]ayed may be held on which is undesir-able at best and may cause damage to the system Moreover, there are several places that will cause wrong notes to be struck in a musical system. In all cases, striking the wrong note sounds much worse than striking no note at all. The first problem is that wlltn tilC recorder is started, or when the electronics are first powered on, there is no synchronization of the internal electronic counters to the data that is re-covered from the recorder until the first sync code is received.
If this is permitted to happen, it can cause wrong notes to be struck at the beginning of replay. The second problem is of more serious consequence, depending on the code used, because if in the middle of tlle replay the tape has a dropout, the electronics lost- the sync and wrong noteC; are struck. Tn any fast scan mult~ lex syste~ a:ll note-: tl~at are on at the time of the dropout may be shifted either up or down the scale until the sync code is recovered again. Finally, accidental detection of a wrong sync code due to noise, misadjustment of controls or the data information contained in the sync code causes the playing of wrong music because of the improper synchronization.
The present invention resides in an electronic keyboard musica:L instrument having selectively actuatable cbr/
key switch dev:ices, means for scanning the key switch devices and producing sequentia]. frames of time d:ivision multiplexed electrical signals from the musical information represented by the selectively actuated condition of the keys, and a magnetic tape storage medium~ bi-phase encoding means for encoding the time division multip:Lexed signals, and means for recording the bi--phase encoded time divisional multiplexed signals on the magnetic tape storage medium as magnetic flux transitions.
In the present invention means are provided for generating a repeated series of musical data cells, each data cell being delineated from an adjoining musical data cell by a sharp ti.ming signal transition and each data cell carrying a predetermined note according to the actuation or non-actuation of the selectively actuatable key switch devices.
Each time frame contains a serial sequence of musical data cells, there being a ti.ming signal transition at the beginning of each musical data cell and the presence or absence of one additional signal transition proximate the center of each musical data cel.l, respectivel.y, const:i.tlltes the musicl.al information correspondlng to the actuation or non-actuation of the key switches, respectively, so that the predominant number of musical data cells are in a zero format wherein the data stream has the effect of essentially all zeros and no musical notes stored therein if a data dropout occurs. The signal transitions on the magnetic tape are recorded in the form of magnetic flux transitions whereby the timing signal transi.tions and musical actuated key switch information are constituted solely by magnetic flux transitions on the tape, cbr/,' r c. s 1~ ( c t ; v c. 1 ~ .
l~he prc~sellt in~7elltion cllso rcsides in a method of prevent:illg the playillg of erroneo-ls notes due to the transit-ion of digltal clata contai~ing data bits in data cells having a b~g:inning and an ending, the data bits corre-sponding to the act~lation or non-actuation of the contro]s of a musi,cia], instrument. In the method, each musical note is assignec~to a data cel]~ and a ti:ming sigrlal transition is located at the beginning of each data cel]. Between the beginning and ending of the data cel] a signal transition or non-transition is ]ocated in each the cell according to the acl-uation or non-ac~t-lnl-iol-, 'respective]y, of the controls.
Tn tile h;--rllase :leve] cc~ded waveform as disclosed in the Vincent patent, there are two significant drawbacks, the first of which is that the phase of the signal m~lst be maintained by the systen- if it be recorded on tape and~
secondly, if a dropout occ:urs the 1-0 relationship cannot be recovered until a 1-0 or 0-1 transition occurs in the NRZ waveform. What actually occurs in the playing of music is that all Y,eros (nc) IllUS:iC) becomes all onc~s (clll llOI:eS
being played). 'i'lli9 a]sc- occurs clllring the stopping and starting of the recorder.
I have discerned that a number of the prob],ems involved in coding systems for musical performances are that the bi-phase leve], code recluires transition to occur in both positLon ancl sense so that in the playing of music, all Y.eros (no music) become all ones (all -4a-cbr/
notes bein plnycd). `f have determined that tbe problem wlth this eoding ~chcme is that in Lhe recording of keybcard music, the lnfor-Dlation ls higllly weiE?lLed with ~eros ~no key closures) and, therefore, in aecordAnce wlth the invention, a code uscd for a slow recorder is sueh that the data (oncC; ar.d ~eros) would look like all ~eros. The bi-phase (or mark) code, as diselosed at page 42 of the Telemetry Standard~ Document 106-71 ( a portJon cf W]liC}! is reproduced in Fig. 2 hereof), has as ~eros inforruation the wide spacing between : transitions. There is always a transieion at the beginning of each bit period which can be recovered as the self-clocking portion of the eode. The information is therefore contained only in the interbit transitions and not in the direction and sense of transition as in the bi-phase level code. ~loreover, the data may be inverted and still be satisfactorily recovered. If a data dropout occurs, the data detector ean immediately regain correct phasing wlthout errors.
The above and other objects, advantages and features of the invention will become more apparent when considered in light of the accompanying drawingc: wherein:
DESCRIPTION OF T}IE DRAWINGS
... .. _ . _ FIG. 1 is a block diagram of an electronie reeord and player system for musical instruments;
FIGS. 2(a), (b) and (c) are n sequence of waveform dia~rams taken from page ~2 of Tolemetry Standards Document 106-71;
FIGS. 3A and 3B, taken together, arc a detailed schematic of the key switch scanning and encoding system incorporating the invention;
FIGS. IIA and 4B, taken together, are a detailed schematic of the playback electronlcs;
FIGS. 5(a-J) are illustrative waveform diagrams with the Z~3 varic)u~ po:ints in l`IC;S. ~A, 3B, 4~ ancl 4~ indicated to thc right:
of eacl~ aveform, for collven:ience, the data bits in each bit period or cell. are shown at the top and bottom of FIG. 5; and FIG. 6(a) is a waveform di.agram of the "D Pulsei' FIGS. 4A and ~B il~ustrating various problems which can occur in the playback of a recorded musical presentation and FIG.
6(b) is a wavefcrm d:iagram of the "blank" pulse corre~sponding thereto.
DETAII.ED DESCRTPrION
There is in ex:istance a service manual entitled "Service ~Ianual for Teledyne Piano Recorder Player Model PP-l Assemb],y Number 3288 ~Tr~ 3263", whi.ch is a publ:ication of the assignee hereof alld is somc!times referred to hereinafter as "Service Manual" and an assembly manual entitled "Assembly Instruction for Teledyne Piano Recorder/Player Model PP-l Assembly NuTnl)er ATIJ-3238 Document Number ATI. 3262, which is a publi.cation of the ass:igllee hereof and sometimes referred to hereinafter as "Installation Manual".
The above-described publications describe in detail a speci.f-ic and preferrecl embc-d~ lent of an e:l.e(:t-ron:;c player p:iano incorporat:ine the :i.nventic)n deE:ined :;,n the claims hereof as made and so].d by the assignee hereof.
~ eferring now to FIG. 1, the keyboard of a piano is desigllatetl by tlle nnmbera]. 10 and ~onstitutes the keyboard-pedal data sourc:e. It could be any musical keyboard source instrument such as a. harl)s:icord, carillon, organ, piano, etc., and each output or switch actuation is indicated by a single line 11-1 throu~h l].-N, tlle number of such output ].ines corre-sponding to the number o~ key switch actuations to be sensed -ancl recorded, for e~amp].e, eighty keys (in one embodiment d:isclosed herei.n~, the "sustain" and "].oud" pedals of . " -6-nn cl~hty--ctgl)t key piano may bc scnsed. A sequlltcc of synchronizing blts from .ync gcTIcrator 10-S ls provided on line ll-S. A Mul~lplexer 12 (sbowll in cletall ill FIG. 3~ scans or looks at each individual linc ll~ S in a times sequcnce whicll constitutcs fra~cs. Thus, thc key switch, sustaill and loud pedal, ~ctuations are sensed by thc digital n~ultLplexer 12, one at a time, and in gencrally se~uential fashion. However, i~ no transpositions are contcmi)la~ed, lt is not necessary that thcy be sequcntially examincd, it bclng evidcnt from ; the dcscription givcn in connection with FIG. 3 that they may be looked at or scanned in groups and in any Iashion or order, the only criteria being that the position of the particular switch in its scan time bc maintained in thc entirc system. The timin~, source 1' is shown in FIG. 3B, and is dcscrlbcd in thc scction hcreafter entitled "Mlllti-plexing" .
The ulultip]cxcr thercby translates the parallel dataof the kcy switch actuations to a serial data stream along its output line 13. lhis data ;s then encodcd to a bi-phasP spacc (or mark) signal in bi-phase space (or mark) encoder 1~l and then recordcd on a tape in tape recordcr 15. It will be appreciated that tape recorder 15 is convcntional in all material respects and need not be disclosed or described in any dctail hcrein. It caln bc thc same as is disc~osed in any of the prlor nrt paterlt-: rcfcrrcll to carlier hereln for record-ing digital data on tape or as showll in thc included "Service" and "Installation" Manuals~
Such tapes may be recordedbeforehand by known or accomplishcd artists or in home recordLngs, or rcrecordings of punched paper rolls, etc. In the case of rccordin~ made by stars, performers and the like, these rccordings may be sold scparately and apart from the rccordin~ system pcr se. That is to say, a tape may be encoded ~ 7-. - ~ - !
nnd thc strlng-; of a ~f.lno, fnr example, struek or aetuEIted by hnn~mer3 or the likc in exEIcLly the :ame minnTler as An accomplis?led artist woulcl be on 21 piallO Wh:LCh is set up for playhaek operation only in the manner illustra~ed in TIGS. 4A and ~IK hereof. In other words, one need not eguip a piano for the reeord funetlon disclosed herein.
On playlack by tile tape recorder 15, the bi-phase spaee (or mar~) data appeclrs at the output of a read head and is fed througl-eorrecting networks and amplifiers to reeover the di~ital signal.
The data from tlle read head is approximately a sine wave, but the OUtpllt from the amplifier on line 16 is a square wave si~nal. ~ore-over, the signal from the read head h215 encoded tllerein the eloek data whieh must be rt-covered arld used in the clemul~iplexillg operation.
The timc recoveIy, bit dropouL, sync counter, bit alld frame eounter eireuitry is shown in lIGS. 4A and l~B and deseribed in detall in the seetion entitled "lhc Deeoder", which recovcrs the timing si~nals, "The Data Dropout Detector" which detects tlle bit dropout, "Sync Counter" for eounting frames of sync pulses and the demultiplex and lateh circuIt.
The bi-phase space (or mark) decoder circuit 17 deeodes the incoming data on line 16 and applies same to aemultiplexer lS
whieh distributes the data to the apE~roprlate eontrol chanllels in the stora~e and solenoid aetunLclr eireuitC 19.
Th~e playbaek loule, shown in FIGS. 3~ and 3B also decodes the exl)ression blts and provides bass and treble DUtpUts to control the volume of play.
Referrln~ now to FIC. 2, the waveforms of a se~uence of data bits (10110001101) are shown in three different bi-phase eneoding sehe:nes, the flrsc of whieh ls shown in llne A of FIC. 2, namely~ the bi-phase level encode scheme. As diselosed in the above-refereneed Telemetry Publieation, this bi-phEIse level (or split phase Manehester ~ 8--.
Il ~ 180), a "onc" i: rc~plcsentcd by a 10, and a "zero!' ~s representcd by a 01. Th~ls, the :crlsc of the transitiorl as wcll as the posltion thercof rcprc~cnts data. In Lhe bi--p?lase space ~or mark), shown in llne n of ~IG. 2, thcrc is a transition at thc bcgillninE of cvcry bit pcriod. ~lowcvcr, a "onc" ls rcprescntccl by no phase shift, l.e., a zero crossil-g, at thc middle of tor intcrblt) the bit pcriod. On tlle other hand, a "zero" in contrast is representcd by a 180 phase shift (i.e., no transition or zero crossing) at thc midd]e of (interbit) the bit period.
The cxact opposite of the bi-phase space (or mark) is shown in llnc C of EIG. 2 whercin a transition occurs at the bc~inning of cvery biL pcr-L(Icl~irl the case of the bi-phase space encoding scheme, but in this casc, tlle represerltntiolls of the one and the zero is cxactly thc revcrse of that shown for the bi-phasc spacc. Thus, in either thc bi-phase space or the bi-phase mark, the sense of the transition is ignored and conveys no information whatcver and it is the presencc, in the case of the bi-phase mark, or absence, in the case of the bi-phasc space, of a transition which dctermines the data.
In accordance with the preferred practice of the present invention, .the: bi-phase syace or mark encoding, format i-; utl]izccl rincc! in this ca5e, thc preclomillnllt number of d;lta bits L9 Ln thc zcro format so that the data strcclrl look-: essentia]ly like all Y.ero.s and if a data dropout, loss of sync, etc. occur~ the system immediately pick9 Up playing ~eros, e.g. not strlking any notcs. Some texts and literature. may ldentify a bi-phase mark code as bi--phase space and vice versa; and some identify tlle code as "freqllency doublinE" or "pulse width ~RZ
1 ...", e.g. see "Digltal ~lagnetic Tape ~ecording for Computer Applications" by l.G. Sebestyen, Chapman and ~lall, 1973.
~ULTIPI.EXING
RCfCrril~, llC~ to F~(S. 3~ and 3B cnch of thc kcy switches is dcsi gn Itl~d b}~ Lh{ nul!lcral S- 1, S-2 ...S-80, tbcrc bcing cigl,t sucll switches in a mod~llc, cach swltcll having an i-;olation elnd blockin diodc associatl:d thcr-wltll, such diodes belng labelcd CR-l and associntccl with switcll S-l and CR-80 is associatcd with switch S-80, etc. Thcsc key sw;tchcs are mllltil)lcxcd in ten groups of eieht and integratcd circuit selcctor U-1 (cac1l integrated circuit element is fully idcntified in tllc "Scrvicc Manual") sclccts tllem one at a time in sequential order until Cig21t arc selected. The sclector circuit 10 U-l I-as as its inputs cloclc/2, clockt4 and clock/8 inputs from seven stage countcr U-6. Thc input to this counter is the cloek input and it cones from a clock circuit 30. Timer circuit 30 contains a con-vcntional oscillntor wllicll with a two-stage counter on its output stnE~c so that thc ouLput is clock and clock dividcd by two. The clock signals "Cl.}~" are applied as the inputs to terminal 1, a seven stage counter U-6, whicll in cffect is a binary decimal decoder having its coded outputs on its output terminals 3, 4, 5, and 6, respcctively, applied to thc input terminals 20, 21, 22 and 23 of one of sixtccn select circuit U-5. Sclect circuit U-5 has terminals 1-17 and the 20 first ten outputs arc uscd as enable signals on output lines 31-0 through 31-9. Thus, each of the modulcs containing switches S-l -S--80 is enabled or strobed one at a time, Thc clock pulses, clock/2, clockl4, and clockl8 from tcrminnls 9, 11 alld 12 of U-fi arc applied to the input tcrminals 9, 10, and 11 of intcgrated circuit U-l and ln conjunction with the 12-volt .5upply and resistors R-3 - R-10, sequentially sample cach of the switches via their blocking diodcs CK-1 - CR-80. Accordingly, there appears on the output terminal of inteErated circuit U-l, a series of pulses, and in the disclosed embodiment, thcre wlll bc one hundred and twenty-eigilt bit periods ,~ 1/ ~10-` ~,it~ f~ tilrl~ it t:~kc; fc,r ~ p~
tc- acL:iv.~ on:~p~lt c~ m;nal :l7 o~ onl- of sclcct c:;rcu:its U-5.
Tilc h-it assigni}lt~nls are sllowll on Cilart ] al)pcari.ng as pagc 21 of th:is clis(~l.osllre; b:;t po';:i.t:ic)nS ~9-10~ are not used and bit pOS;t:iO~ LG is not u~ed along wi.th b:it positions ]19 and 120.
As shown c>n î:he "bit assignment chart", thc sustclin and soft pedals occupy bit pos:it:i.ons 117 and 11.8 in the frame whereas the bit 105-109 ansl lll-lL5 are ~Ised to activate the bass theme and bass thcme intens:ity levels and the treble theme ~nd treblc intensity controls, respec~t:ively. ~inally, bit positions 121-128 are assigncd to thc synchronizi.ng bits which are generated whell a strobe p-l]se appears on pin ].7 of U-59 the zero at bit posi.tion 127 is a cilc(k b:i.t:.
}~,NC'()I)ING (FI(,S. 3~ ~ 3B) It w:ill bc noted that the output: vf the selection circu:it U-l is in time frames with the data bei.ng in non-return to zero code format-. Thi.s date (F .tG . 5a) is applied as one inp~lt to the cncod:ing circuit. As discussed earlier, in the recording of keyboard m~lsic, the inEormation is highly weighted with zeros, that is, there are no key clos~lres and, Lherefore, according to thi.s invcllt:ioll, thc cod-- l.s ';~tC21 that for a slow rccorder thc data (OIIC`'; all(l 7,erog) WOIIld a.l.l loolc like zeros.
As shown at page ~2 of the Telemetry Standards Doc~lment 106-71, the bi-phase space cocle has as zeros information the w:icle spac:ing l)cl:wecn trallC;i.tions. 'l'he information is contained in the trans:it:ions only and not in the direction or sense of the trans:ition as in thc! b:i--phase level code. Thercfore, the data may be inverted and still be satisfactor:ily recovered. If a dropout occ-lrs, the dilt.a detector immecliately regains phasing wi.tllout crrors as disc:llssed later herc:in. The c:i.rcu;t util:izecl c ~ u to ~l.'llCI~ ` th~` c~di` .iS ';ilO~ in l~I(. 3B a~d has a NAND gate U-4C
whicil receivc; Lhe NR~ dlta frolll t:he ~nultiplexcr circuit 12.
The ~R' dat.l :i.s g.qted in NANl) gate U-4C at ~he clock rate is to generate the JK input~ to fli.p flop IJ-2B. The 2x clock is applied as one input of U--2B and the output of NAND gate U-4C
are applied as illpUtS to produce and generate the bi-phase space/mark data. This data is applied to an output follower circuit (which is not here relevant) and this signal is the signal that is applied to the input terminals of the recorder for shaping and recording upon magnetic tape. See the "Service Manual".
Thus, as the artist plays the music upon the keyboard, the keyboard switches, S-l - S-80~ are closed and are scanned at a selected clock rate. This data i.s then multiplexed by the multiplexing arrangement described earlier herein to provide an NRZ data which is gated in NAND gate U-4C to generate the JK
inputs to flip flot U-2B. The 2x clock from timer 30 (FIG. 5b) clocks the flip f].op and the Q output of U-2B is the bi-phase space code (FIG. 5b) which is tape recorded.
It is, of course, not necessary that the musical data originate with a keyboard, for exaDlple, a punclled paper piano roll can be converted to tape form by a brush-hole sensing arrangement with the brushes scanned as if they were the key switches S-l - S-80.
T~IE DECODRR (FIGS. 4~ & 4B) _ _ _ The decoder is shown in FIG. 4~ & 4B and includes the EDGE detecti.on circuit utili~ing U-2 (of FIG. 4A & 4B), the "D Pulse" monostable U-3, and the decoder using U-18. The four exclusive OR gates of U-2 and the delay generated by capacitor Cl generllte a narrow spi.ke called EDGE as shown in FIGS. 4A & 4B.
cbr~J G
~8~9k3 ol-r~ to l::L(,. ~A~ n a ~,~ro ~is pr~s~nt: at pi.n ~ of U-2C, p;n 8 ~ o~of wi]l bc ll:igll WhiCil p1accs a higll ~t pin 2 of U- 2A an~l it ~i o~ltpUt p:in 3 will go higl - 1 2 a -cb r /) '~
~L~18~43 delayed by cap.lcitor Cl. This is applied to pin 13 of U-~ so that pin ll thereof will go low and a pin 6 of U-2B
goes high. At the next transition (the small "b" shown in the waveform diagram leading into pin 9 of U-2C) pin 5 of U-2B will go low and pin 4 remains high momentarily so that a negative going pulse appears at pin 6 of U-~B. Each time a transit:ion occurs another pulse is produced. These pulses are supplied to pin 5 of the monostable multivibrator U-3 and each time pin 5 of the multivibrator goes from zero to high, the OtltpUt pin of the multivibrator will go high. The multivibrator U-3 begins to time out when set by RC resistors 46, 47 and capacitor ~15. The time out ls set to be three quarter bit time. Once U-3 has timed out, pin 6 of the multi-vibrator U 3 returns to zero ready to be re-set. Multi-vibrator U-3 then produces one output for each bit.
DATA DROPOUT DETECTOR
As described earlier, and Witll reference to Fig. 6, if a dropout of data occurs in the tape recording, there can be a loss of sync which causes wrong notes to be struck during the frame of data in which the dropout occurs and this can be quite di-;concertLng to the llstencr. The same disconcerting p]aying of notes can occur if the tape recorder is stopped while notes are being played. The objective of this portion of applicant's invention, which is also described and is claimed in above-identified parent application Serial 276,996, is to sense or detect the dropout of data so as to prevent the playing of undesirable notes and/or avoid damage to the system. The circuit portion of FIGS. 4A & 4~ which is most significant for this aspect of this invention is block cbr/'~i 3X~3 11-4 whi~ is tlli retl-:ig~el-al)le data detector. The output oL re~tri~er~ble nlonocitclble mlllt:ivibrator circuiL U-~stays h~ as in(l;cated :in the waverorm diagrlm from the output: terminal 9 for a time determ:ined by the values of feedback cap<lc-itor -13a-cbr/
~3 arl~l r~;istol 39. A ~liod~ 38I) :is tlsed io d:i.~ch~rg~ the capacitor 3~. In t~le beginll:irlg, p~l:l.scs arc apl)lied from the taye recorder output c:i.rc~l:l.t:, wh:ich are alllplified by transistvrs Ql and Q2 and their associated resisto~ nctworks and applied as an input to optical couple 1l-1. This optical coupling circuit U-l is conventiDnal, having as an output thcreof a square wave whicll is applied as an input to transistor amplif~er 40.
The outpu~ of transistor amplifi.er 40 is the bi-phase space encoded data. The edges tr:igger the non-retriggerable mono-stab].e multivibrator U-3 and the length of time the Q output of this multivi'brator is hi.gh is determined by capacitor 45 and resistors 46 and 47, resistor 46 be:ing adJusted so tllat tlle D pulse output is three quarters thc bit time oL thc :information. I~lth the bi-phase space/mark code described above, when the first ~ero of the data occurs, the monostable begins to trigger on the edge that exists at the end of the bit cell. As noted earlier, there :is a transition at the beginning of every bit period which is the same as the end of the bit cell for the succeeding period. The edge that occurs, due to a one on the middle oE the'bit cell is ignored due to the timing and delay which comes abDut from the adjtlstmentc; oE the ctlpac:Ltol-s and resistors descrLbed abovc. Thc edge ls then ut-.Lli~ed to clock the CI.K or clock input to D flip flop U-18, and the D pulse is applied to the D input of edge detector U-18, with the Q output thereof shown in FIG. 5. The negative cdge of the D pulse is used to store the output of U-18 :into the i.nput register oE the eight bit input rcgi.ster U-l9. The NRZ data is recovered as shown in FIG. 5. The NRZ data at thc Q output of U-18 may be supplied to a shift register (not shown) for transposition purposes, if desired.
Rcfcrr:Lng now to the retriggerable monostable mult:i-j]./ -14-vibrn~or 1l--4, as lonE as thc positivz gOillg cdg{s occur ln less thn predetcrmi,lcd ttmc, thc ~nonostaz)le is rcsct and beEins timing ou~
again. If, due ~c> a slow tapc speed, data dropout or rccordcr stopping, or no lnformaeion bcing recordcd oll the tapc, e.g., a blan~ tapc, no ed~,e occurs in thc 1) pulsc input of rctriggcrablc data detector U~4 and thc dcvice timcs out and clearc: thc sync countcr constieuted by integratcd circuits 1l-10~ and U-lOB and the input reglster both of which prevent notes from being struck or hcld in zl closed statc.
The tlming shown in FIG. 6 is adJustcd to just lon~er than the expected time between the positive going edgc of the ~ pu15c. If the edge docs not occur during the expcctcd time, thc output drops and clcars the sys tcm.
T~ YNt,_COU~'rl~.R
As discu-i<;ed carlier (FIG. 4A 6 4B), if there is a loss of synchronization, wrong notes can be struck by the musical instru-ment which can be quite disconcerting. The prior systems sensed these sync codes and automatically reset. In accordancc with the present inventioz- to insurc that at power on, and at the start of a tape recorder or after a data dropout on the tape, no wrong notes are struck, a sync countcr has been utilized to count three sync codes before allowing any notc to be struck (these would be the thrce sync sequenccs in thc bit assignmcnt chzlrt at blt posltiolls 121-128). Thi.q countcr is rcsct by thc output data dctector circuit U-t~ line i~8 ~labeled "Bl.ln~'l) that dctects if there is data dropout on the tape or the Lape rccorder is running at the wrong speed or that the power has Just been turncd on. This sync counter, constituted basically by intcgrated JK flip flop clrcuits U-lOA and U-lOB, also allows for the po5sibility that thc aync codc could possibly occur randomly ln the data information and rcJects the false sync.
Jl/ -15-~ ( r~tr;~ cl.lJ,'~ da~ cletect(-r circ~it U~ h~s a IJ~III< o~t~ t w~ ich ~ S ~h( COUII~CI- to a 7.ero courlt if tilere is not a~ly data bl~i[lg rcce3v~(l, at po~c~r on, if ~ tape dropout occur~;
or if tape sl~ee~l varia~iolls exist. IE the ~ output of U-lOA or ~-lOB is ~ero, U--llR N~N~! gate i9 higll, a register clear pulse clears all output reg:isters to thereby preveilt any key.s (notes~ from being played. Therefore, ull~il both JK flip 10ps U--lOA and U-lOB outputs are high (one) there cannot be any notes played or struck. NAND
gate U-13A output ]oad)' holds the b~t counters U-l~i and U-15 to all ones count, wh:ich, in turn, is detected by NA~I) gate U-9. When the incoming data from U-18 is sh-ifted through the eight b:it input register U-19, and contaills no sync code, the NAND gate U-6 detects same and sync dettct outl)llt become~s low. When the o~ltpUtS of NANI) gates U-6 and IJ-9 are low ag well as the Q output of JK flip rlop U-lOB and the data detector (Q of U-4~ :is high, the next pulse (the D pulse at Q of U-3) is coupled through resistor R-ll and diode CR-2 and delayed by capacitor 38 and clocks U-lOA arld U-lOR as well as clocking the bit counter wh:ich has been released by U-13A load 27 output.
At this time, the J and K OUtplltS of f]Lp f:Lop U-lOA
are zero and the J and K OUtp~ltS oF U-lOIi are one clud the CL~ changes U-lOB Q to a one alld inverted Q to a zero. The b:it eounter U-14, U-15 eontinues to count until it counts 128 eounts and returns to all ones agaln. If the data is eorrect and the retriggerable data dc-tector U-~ b~ank output Stclys high, the sync code is again in the eight bit regLster U-19. IJ~G and U-9 detect the sync tirne again together wh:ich allows U-lOA J to go to a one and the U-lOA K to zero, wliile U-lOB J and K go to one When the U-lOA and U-lOR are clock, they both change states so as U-lOA ~ is one and U-lOR is zero.
jl/ -16-lhe re~istcr el~ar (~c~. Clr) sl~ tnys high and ~he key~ are stlll not 3110wed to play. After ]28 more counts, U-lOB J is high nnd upon clocking, U-lOB Q becomes a one and the reglster clear becomes a ~ero, thus a110wing the notes to bc struck. In es6ence, then, the system require~. two eomplete rames of 128 bits before any notes may be struck after any disturbance eausfn~ the data detectc)r or sync detecc NAND gnte to indic~te a malfunction. As indicated earlier, the eounting of two frames of syne pulses is illustrated in the context oE Vincent patent 3,905,267.
DEMULTIYLEX AND LATCII
The bit eounters U-14 and U-]5 along with the 8 bit input re~,ister U-l~ demultiplex th~ serial data stream from the Q
output terminnl of U-18. Eaeh sueeecclinr7 bit is sequentially shifted into shift rcgister U-19, and then transferred to lateh eireuits L-l, 1,-2...L-N corresponding to the number of modules (10 in this ease) eontaining key switehes S-l - S-80. Bit eounter outputs CR-8, CTR-16, CTR-32 and CTR-64 are supplied to 4 line to 16 line eonverter U-5 so that upon tlle output ]ines thereof appear, in sequenee, enabling pulses for eaeh of the lateh elreuits L. Bit eounter outputs CTR-l, CTR-2, CTR-4 are the unit select inputs to expression and pedal lateh eireuits EYI.-l and EYI,-2 ~U-20 and U-21).
As Ishown in Flg. 4B C~Ch l.atch elreuLt I,l, L2...1.N
reeeives the data bits on tneir re6peetive data Input terminals D
~terminal 13) frolll the 8-bit input register U19 (FIG. 4A) whieh delays the data one bit time. The data is supplied serially in the storage unlts of the laten eireuits Ll, 1.2...LN. As the data is sent, eounters U14-U15 (FIG. 4B) and the 4-line to 16-line eonverter (U5 of Fig. 4B).
storage plaee in the latch eircuits for eaeh bit. Thus, the eounter 1, eounter 2, and eounter 4 output bits (CTRl, CTR2, and CTR4) ~ 17-detern~ne whicII !~I.ac.e a bit is to be stored in a grc)l-p of eig2lt so that as eaeh latch circuit ls ellal.le.d~ the data bits issuLnE from the 8-bit input register, delayed one bit at a time, are stored in the lateh circuits with the outputs of the 4-line to 16-line eonverter (U5 of Fig. 4B). A total of 16 ~,roups times 8 per group whieh rnakes 128 ehannels with the first group bein~, seleeted by the one output terminal of U5 nnd aEi indieate(l in Fig. 4B (see paragraph 3.5.6 "Data Transfer" of the Teledyne Serviee ~Ianual).
Thus-, eaeh of the lateh eircuits L stores the musical lo information eont<~ined in a data eell of the 128 bit time frame.
Driver trane.i.~tor AND gates DG, one for each key on the keyboard reeeive as on~ i.nput a r.lgnal .Erom the ].atch or storage eireuits l The second input to the dri.vertransistor AND gate DG is a sequence of pulses which are width modulat~d aeeording to the information stored in e~pression and pedal control latch eircui.ts NI'I
EXPRESSTON
A low frequency (200 ~I~) oscillator 70 supplied pulses to a pair of pulse width modulatable one 57l0t monostable multivi-brators 71 and 72 for the bass and treble keys, respeetively. The pulses from oscillator 70 have their mi.~ um w:idth set by a variable resi~tor 73 which thus setE the mi.n:imulll wiclLh of thc pulses from multivibrator~ 71 and 72. Each multivibrator 71 and 72 has its timing set by capacitors 74 and 75, respectively, in eonJunetion with resistors 76-80 for bass theme and resistors 81-85 for the treble theme. Combinat:Lons of resistors 76-80 and eombinations oE
resIstors 81-85 are seleeted by the information eontained in eounter bits CTR-l - CTR-4 which have been stored in expression and pedal eontrol latch eireuits U-20 and U-21, whieh are enabled by two sueeessive outputs (line 13 and line 14) from the four line to sixteen line converter U-5. This stores the treble and bass ~re: -` 1~18243 e,xpression bits in latch circuits EPL-l and EPL-2 along with the soft and sustain pedal controls. It will be noted thAt the latter are also prevented from being actuated on data dropout, loss of sync, etc. by a "Register Clear" signal at U-17B and U-17D. The stored bits are used to vary the number of resistors R76-R80 and R81-R-85 (which are essentially binary weighted) in circuit with timing capacitors 74 and 75, respectively, to thereby vary the charging rate of the capacitors according to the combination of resistors which have been in effect, connected in circuit with capacitor (74 or 75), to thereby vary the width of the pulses established by U-22A for bass effects and U-22B for treble effects.
I ` ~8;~43 The bass efect pulse width pulses are supplied to the group of driver transistor AND gates DG-B for the bass notes solenoid control as the second input thereto and the treble effect pulse width modulated pulses are supplied to the driver transistor 5 AND gatesDG-T for the treble note solenoid control transistors.
If the sync pulse sequence is detected and there has bee no loss of sync, data dropout, etc. as described above, the musical notes stored in the latch circuits are played.
' It will now be seen how the invention accomplishes its various objects and the various advantages of the invention will likewise be apparent. While theinvention has been described and illustrated herein by reference to certain preferred embodiments, it is to be understood that various changes and modifications may be made in the invention by those skilled in the art, without departing from the inventive concept, the scope of which is to beA
determined by the appended Flaims.
. , ',,.
BIT ASSIGN,'~ENT
1. CBlC 44. Glt 87. B32
2. 1) 45. A 88. C16
3. DH 46. A# 89.
47. P. 90.
` 5. F 48. C 91.
6. F~ 49. CR' 92. o 7. (; 50. D 93.
8. Ge 51. DB 9~1, 9. A 52. E 95.
10. Ab 53. F 96.
11. B ~4.. J-B 97, 12. C 55. ~i 98 . o 13. C8 56. t~l~ 99.
- l~S. D 57. A lOD.
15. DB 58. AB 101.
16. E 59. B 102.
17. F - 60. C 103.
18. F~ 61. Clt 10'1. o 19. G 62. D 105. XASS T~IE.E
20. GB 63. I)B 106. BASS INTENSITY 1 21. A 64. E 107. BASS INTENSITY 2 22. AR . 65. 1 108. BASS INTE.NSITY 3 23. B 66. I:B 109. BASS INTENSlTY 4 24. C 67. G 110. 0 25. Cn 6S. Gf~ 111. ~REBLE T~IEME .
26, D 69. A 112. TREBLE INTENSITY 1 27. DR 70. A~ 113. l`REBLE INTENSITY 2 28. E 71. B 11~. TREBLE INTENSITY 3 29. F 72. C 115. TREBI.E INTENSII'Y 4 30. ~ 73. C~ 116. o 31. G 7'1. D 117. SUSTAIN PEDAL
32. G~ 75. DB llS. SOFT PEDAL
33. A 76. E 119.
34. AB 77. E 120.
35. B 78. Fl~ 121. 1 36. C (~IIDDLE) 79. G 122. 1 37.- CB 80. GB 123.
3S D 81. A 12'1.
39 DR 82. AB 125. 1 . SYNC
40. E 83. B 126. 1 41. ~: 84. C 127. o 42. FB 85. A32 128.
43. G 86. A#32 114 UNASSIC~;ED BITS)
47. P. 90.
` 5. F 48. C 91.
6. F~ 49. CR' 92. o 7. (; 50. D 93.
8. Ge 51. DB 9~1, 9. A 52. E 95.
10. Ab 53. F 96.
11. B ~4.. J-B 97, 12. C 55. ~i 98 . o 13. C8 56. t~l~ 99.
- l~S. D 57. A lOD.
15. DB 58. AB 101.
16. E 59. B 102.
17. F - 60. C 103.
18. F~ 61. Clt 10'1. o 19. G 62. D 105. XASS T~IE.E
20. GB 63. I)B 106. BASS INTENSITY 1 21. A 64. E 107. BASS INTENSITY 2 22. AR . 65. 1 108. BASS INTE.NSITY 3 23. B 66. I:B 109. BASS INTENSlTY 4 24. C 67. G 110. 0 25. Cn 6S. Gf~ 111. ~REBLE T~IEME .
26, D 69. A 112. TREBLE INTENSITY 1 27. DR 70. A~ 113. l`REBLE INTENSITY 2 28. E 71. B 11~. TREBLE INTENSITY 3 29. F 72. C 115. TREBI.E INTENSII'Y 4 30. ~ 73. C~ 116. o 31. G 7'1. D 117. SUSTAIN PEDAL
32. G~ 75. DB llS. SOFT PEDAL
33. A 76. E 119.
34. AB 77. E 120.
35. B 78. Fl~ 121. 1 36. C (~IIDDLE) 79. G 122. 1 37.- CB 80. GB 123.
3S D 81. A 12'1.
39 DR 82. AB 125. 1 . SYNC
40. E 83. B 126. 1 41. ~: 84. C 127. o 42. FB 85. A32 128.
43. G 86. A#32 114 UNASSIC~;ED BITS)
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In an electronic keyboard musical instrument having selectively actuatable key switch devices, means for scanning said key switch devices and producing sequential frames of time division multiplexed electrical signals from the musical information represented by the selectively actuated condition of said keys, and a magnetic tape storage medium, bi-phase encoding means for encoding said time division multiplexed signals, and means for recording said bi-phase encoded time division multiplexed signals on said magnetic tape storage medium as magnetic flux transitions, improvements in said bi-phase encoding means which comprises:
means for generating a repeating series of musical data cells, each data cell being delineated from an adjoining musical data by a sharp timing signal transition and each data cell carrying a predetermined note according to the actuation or non-actuation of one said selectively actuatable key switch devices, each time frame containing a serial sequence of musical data cells, there being a timing signal transition at the beginning of each muscial data cell and the presence or absence of one additional signal transition proximate the center of each musical data cell, respectively, constitutes the musical information corresponding to the actuation or non-actuation of said key switches, respectively, so that the predominant number of musical data cells are in a zero format wherein the data stream has the effect of essentially all zeros and no musical notes stored therein if a data dropout occurs, and recording signal transitions on said magnetic tape in the form of magnetic flux transitions whereby the time signal transitions and musical actuated key switch information are constituted solely by magnetic flux transitions on said tape, respectively.
means for generating a repeating series of musical data cells, each data cell being delineated from an adjoining musical data by a sharp timing signal transition and each data cell carrying a predetermined note according to the actuation or non-actuation of one said selectively actuatable key switch devices, each time frame containing a serial sequence of musical data cells, there being a timing signal transition at the beginning of each muscial data cell and the presence or absence of one additional signal transition proximate the center of each musical data cell, respectively, constitutes the musical information corresponding to the actuation or non-actuation of said key switches, respectively, so that the predominant number of musical data cells are in a zero format wherein the data stream has the effect of essentially all zeros and no musical notes stored therein if a data dropout occurs, and recording signal transitions on said magnetic tape in the form of magnetic flux transitions whereby the time signal transitions and musical actuated key switch information are constituted solely by magnetic flux transitions on said tape, respectively.
2. A playback system for the magnetic tape storage medium defined in claim 1 comprising:
reading means for detecting said magnetic flux trans-itions recorded on said magnetic tape to produce a serial stream of encoded musical data bits, decoding means for decoding the encoding musical data bits, demultiplexing means for demultiplexing and storing the decoded musical data bits, electrically operated music producing keyboard means having selectively actuatable keys, and means for applying the stored data as decoded to the keys of said electrically operated music producing key-board means to reproduce the music as recorded.
reading means for detecting said magnetic flux trans-itions recorded on said magnetic tape to produce a serial stream of encoded musical data bits, decoding means for decoding the encoding musical data bits, demultiplexing means for demultiplexing and storing the decoded musical data bits, electrically operated music producing keyboard means having selectively actuatable keys, and means for applying the stored data as decoded to the keys of said electrically operated music producing key-board means to reproduce the music as recorded.
3. The invention defined in claim 1 wherein said means for generating a repeating series of time frames includes means for generating a sequence of synchronizing bits at a selected position therein to constitute a synchronizing signal, counter means for counting at least two sets of synchronizing bits, and means controlled by said counter means for preventing the playing of any notes by said music producing means until a continuous sequence of two sets of synchronizing bits occurs in at least two succeeding time frames.
4. The invention defined in claim 2, including means for preventing the playing of any noies on loss any data in any one time frame.
5. In a method of preventing the playing of erroneons notes due to the transmission of digital data containing data bits in data cells each data cell having a beginning and an ending, said data bits corresponding to the actuation or non- actuation of the controls of a musical instrument, comprising the steps of:
assigning each musical notw to a data cell, locating a timing signal transition at the beginning of each data cell, and between said beginning and ending of said data cell locating a signal transition or non- transition in each said data cell acoording to the actuation or non- actuation, respectively, of said controls.
assigning each musical notw to a data cell, locating a timing signal transition at the beginning of each data cell, and between said beginning and ending of said data cell locating a signal transition or non- transition in each said data cell acoording to the actuation or non- actuation, respectively, of said controls.
6. In a method of preventing the playing of erroneous notes due to the transmission of digital data contained in data cells as defined in claim 5, the improvement wherein said data to be transmitted is recorded on magnetic tape and said signal transitions or non- transitions are magnetic flux transitions and non- transition 24 ons.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000354537A CA1118243A (en) | 1976-04-28 | 1980-06-20 | Method and apparatus for reproducing a musical presentation |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US681,093 | 1976-04-28 | ||
| US05/681,093 US4132142A (en) | 1976-04-28 | 1976-04-28 | Method and apparatus for reproducing a musical presentation |
| CA276,996A CA1085658A (en) | 1976-04-28 | 1977-04-26 | Method and apparatus for reproducing a musical presentation |
| CA000354537A CA1118243A (en) | 1976-04-28 | 1980-06-20 | Method and apparatus for reproducing a musical presentation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1118243A true CA1118243A (en) | 1982-02-16 |
Family
ID=27165049
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000354537A Expired CA1118243A (en) | 1976-04-28 | 1980-06-20 | Method and apparatus for reproducing a musical presentation |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1118243A (en) |
-
1980
- 1980-06-20 CA CA000354537A patent/CA1118243A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3905267A (en) | Electronic player piano with record and playback feature | |
| US5416526A (en) | Sound and image reproduction system | |
| US4768412A (en) | Low profile keyboard device and system for recording and scoring music | |
| US4519008A (en) | Method of recording and reproducing visual information in audio recording medium and audio recording medium recorded with visual information | |
| US5701153A (en) | Method and system using time information in textual representations of speech for correlation to a second representation of that speech | |
| US3647929A (en) | Apparatus for reproducing musical notes from an encoded record | |
| US4132141A (en) | Solenoid-hammer control system for the re-creation of expression effects from a recorded musical presentation | |
| US5321200A (en) | Data recording system with midi signal channels and reproduction apparatus therefore | |
| GB2201282A (en) | Tone information processing device for an electronic musical instrument | |
| KR100252399B1 (en) | Music information recording and reproducing methods and music information reproducing apparatus | |
| US3955459A (en) | Electronic musical instrument | |
| KR950004253A (en) | Karaoke device back chorus playback device | |
| US4899632A (en) | Multi-recording apparatus of an electronic musical instrument | |
| KR900012162A (en) | Memory Remote Control | |
| US4104950A (en) | Demultiplex and storage system for time division multiplexed frames of musical data | |
| US4176578A (en) | System for encoding of bass and treble expression effects while recording from the keyboard of an electronic player piano | |
| CA1118243A (en) | Method and apparatus for reproducing a musical presentation | |
| US4132142A (en) | Method and apparatus for reproducing a musical presentation | |
| US4174652A (en) | Method and apparatus for recording digital signals for actuating solenoid | |
| de Oliveira et al. | Understanding midi: A painless tutorial on midi format | |
| US6121534A (en) | Natural-scale tone-generator apparatus for MIDI musical keyboards | |
| GB2157913A (en) | Signal recording system for recording signals on a rotary recording medium | |
| US4373415A (en) | Electronic musical instrument | |
| CA1122448A (en) | Dynamically adaptive player piano roll to magnetic tape formating system and playback | |
| US4143807A (en) | Music roll perforating process and apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |