perm filename USEMUS.LCS[UP,DOC]8 blob
sn#219395 filedate 1976-06-17 generic text, type T, neo UTF8
00100 ********** Using the Music System -- MUS10 **********
00200
00300 ******* WORK IN PROGRESS -- JUNE 76 -- LELAND SMITH *********
00400
00500 This manual is designed for use with the PDP10 at the Stanford AI lab.
00600 It is quite possible that several features discussed will not be
00700 operative on other installations. See appendix for some details.
00800
00900
01000 MUS10 is a complete sound generating package which exists on the
01100 disk. For first attempts type:
01600
01700 R MUS10
01800 (All lines must be terminated with the 'RETURN' key.)
01900
02000 At this point the program will type the message:
02100
02200 INPUT?
02300
02400 Basically there are two responses possible. If the program is to
02500 receive further instructions from another file which has been
02600 prepared with an editing program, type:
02700
02800 NAME -- where NAME is the name of the file to be read.
02900 (If NAME has an extension, it must be used!)
03000
03100 If instructions are to be entered by means of the teletype keyboard
03200 (TTY mode), type carriage return (<CR>).
03300
03400 At this point a star (*) will appear which means the program is
03500 awaiting input.
03600
03700 Most complete statements to be read by MUS10 must end with a
03800 semicolon. Several complete statements may be entered on a single
03900 line but it is best not to have the lines too long. More than one
04000 line may be used for a single statement. If the less-than sign (<)
04100 appears everything following on that line will be ignored. Use this
04200 for entering comments.
04300
04400 ***** Note that the above rules DO NOT apply to the syntax
04500 of the SCORE program.
04600
04700 Already present in MUS10 is an "instrument" known as SIMP which has
04800 been set to play a test tone of 'A' (440 hz) for 1/2 second.
04900
05000 In order to play this tone, first get into TTY mode as described
05100 above, then type:
05200
05300 PLAY;SIMP;FINISH;
05400
05500 When the computation begins "MUSAA" will be typed out. This means
05510 that sound data is being written on the disk under the name
05520 "MUSAA.SND." When the computation is finished the program will type
05530 "MUSAA AMPL.=2000." Immediately after this the following message will
05540 appear: SPEED?, <CR>, OR "X". This means you have three options.
05550 <CR> means to hit the "RETURN" key. This will cause the computed
05560 sound to play (unless someone else's program has momentary control
05570 over the devices you need.) Each time you hit the "RETURN" key the
05580 sound will play again.
05582
05585 The sound will be playing at SPEED 1. The SPEEDs available are 0
05595 through 5. 0 plays 1/2 as fast as 1, hence an octave lower; 2 play
05605 twice as fast; 3 plays four times as fast; 4 play eight times as
05615 fast; 5 plays sixteen times as fast. If a SPEED number is typed (DO
05625 NOT hit "RETURN" here) then "GO?" will be appear. At this point type
05635 any other character (other than <CR> or X) to hear the sound. If you
05645 type "X" the program will exit from the "play" mode and return the
05655 symbol "*", which means it is waiting for some new command. When "X"
05665 is typed, you will get the message "PLEASE DELETE MUSAA.SND." This
05675 means that when you have finished your work you should type <CALL>,
05685 then "DEL MUSAA.SND <CR> so the space on the disk taken up by your
05695 sound tests may be reclaimed.
05705
05710 If you have typed an "X" but wish to return to "play" mode, type $P;
05720 where '$' indicates the 'ALT' key.
05730
07600
07700 ******************************************************
07800
07900 The instrument SIMP has five parameters.
08000
08100 P1 = begin time of note (in seconds)
08200 P2 = duration of note " "
08300 P3 = pitch
08400 P4 = amplitude
08500 P5 = wave form (or timbre)
08600
08700 P1 and P2 will have the same significance in all instruments but all
08800 higher numbered parameters are assigned roles according to
08900 convenience. (However it will prove useful to consistently apply P3
09000 and P4 as above.)
09100
09200 Internally all pitch entries become numerical, however the twelve
09300 frequencies of the tempered chromatic scale, from middle C (261.62
09400 hz) up to B may be used in MUS10 by typing the letter names of the
09500 notes. The letter S = #, F = flat.
09600
09700 Since these letters merely represent the frequencies of each note,
09710 the octave range may be changed by multiplying or dividing by
09720 multiples of two. Thus C or A in the octave below middle C would be
09730 entered as C/2 or A/2. In the octave above the basic middle octave
09740 these notes would be C*2 or A*2.
10200
10300 C -- 2 octaves down would be C/4
10400 C -- 3 octaves down would be C/8
10500 C -- 2 octaves up would be C*4
10600 C -- 3 octaves up would be C*8 etc.
10700
10800 To test the use of these letters try:
10900
11000 P3←C;PLAY;SIMP;FINISH;
11100
11200 Now instrument SIMP will compute middle C instead of A. The left
11210 arrow (←) indicates that the value of C has been placed in P3,
11220 replacing any value that was previously there. (The left arrow and
11230 the equals sign[=] are interchangeable in this program.)
11600
11700 PLAY;SIMP;FINISH; must be typed so the new note will be computed.
11800 After it is first heard it may be repeated as indicated above.
11900
12000 If frequencies other than those of the tempered scale are to be
12100 played, a number may be used instead of a letter.
12200
12300 P3←1000;PLAY;SIMP;FINISH; will play a tone at 1000 hz.
12400
12500
12600 The amplitude scale available is the range of number from 0 to 2047.
12700 (This upper limit is set by the number of bits [12] used for the
12800 sound samples. See appendix.) P4 has been set at 2000 for the test
12900 tone. This may be reset using the same method as described before.
13000
13100 P4←100;P3←GS*2;PLAY;SIMP;FINISH;
13200
13300 This will play a G# above the middle octave at amplitude 100.
13400
13500 The duration of the tone may be changed be resetting P2.
13600
13700 P2←.1; etc. will play a note of 1/10 sec. duration.
13800
13900 In general, test tones should rarely exceed 1" duration.
15100
15200 When several parameters are to be changed at once the following
15300 type-in format should be used:
15400
15500 PLAY;SIMP 0 .2 FS/2 850;FINISH;
15600
15700 This will play F# below middle C for 2/10" at an amplitude of 850.
15800 (Please note that P5, the wave form for SIMP, will be dealt with
15900 later.)
16000
16100 ********** COMMAS **********
16200
16300 Commas may be used to separate the parameters and if nothing precedes
16400 a comma the contents of that parameter remains unchanged. Also any
16500 parameter numbers higher than the length of the list will not be
16600 affected.
16700
16800 PLAY;SIMP ,.3,,1200;FINISH; changes only P2 and P4.
16900
17000 ******************************************************
17100
17200 A string of notes may be played with the following input:
17300
17400 PLAY;SIMP 0 .2 C 1500;SIMP .2,,D;SIMP .4,,E;
17500 SIMP .6,,C;FINISH;
17600
17700 In this case P1 must be updated for each note. (Never overlap an
17800 instrument with itself. Distortion will occur.) P2, the note
17900 duration remains unchanged, so the commas suffice for the last three
18000 notes. P4, coming at the end of the list for the first note need
18100 only be stated once if it is not to change.
18200
18300 Rests are created by simply leaving some time between the end of one
18400 note (P1+P2) and the beginning of the next (the new P1).
18500
18600 PLAY;SIMP 0 .2 C;SIMP .5;FINISH; will play C for 2/10",
18700 rest for 3/10" and then play another C for 2/10".
18800
18900
19000 ********** FUNCTIONS **********
19100
19200 The wave form in P5 is entered by means of a name which is used by
19300 the program to locate a list, or array, of numbers (512) which
19400 describe the wave. The names used for this purpose will always be F
19500 followed directly by a number. These arrays will be called
19600 "functions."
19700
19800 Only one function is in MUS10, although more can be added. The
19900 function present is known as F1 and describes a sine wave. To see
20000 this wave on the CRT type:
20100
20200 SEE(F1);
20300
20400 To clear the screen hit the 'ESC' key followed by a 'C'. (This is
20500 called ESCAPE C.) <CR> will bring back the typescript display if it
20600 is gone.
20700
20800 Functions may be created with an external program called FUNC or
20900 within MUS10 itself by means of two routines called SYNTH and SEG.
21000 SYNTH is used to create composites made by adding various harmonics
21100 together. The form of F1 could be changed in the following manner:
21200
21300 SYNTH(F1); 1,1 2,1 3,.5 999;
21400
21500 In the three pairs of numbers, the first of each pair represents the
21600 harmonic number and the second the relative amplitude of that
21700 harmonic. Thus the ratios of harmonics 1, 2 and 3 will be 1:1:.5 .
21800
21900 The size of the second number of each pair is important only in its
22000 relation to the other amplitude numbers. The last number, 999, is
22010 used to signal the termination of a string of entries.
22200
22300 Several pairs may entered and harmonic numbers up to 256 may be used
22400 but in practice great care must be taken to avoid the "foldover"
22500 effect which occurs when frequencies higher than one half the
22600 sampling rate are present. (See appendix.)
22700
22800 It should be pointed out that the fundamental (harmonic #1) need not
22900 be present in a wave.
23000
23100 SYNTH(F1); 10,1 12,1 15,1 999; will give the three notes
23200 of a minor chord. After this has been entered the following will
23210 cause a C minor chord to play:
23400
23500 PLAY;SIMP 0 .5 GS/8;FINISH;
23600
23700 While the lowest Ab (or G#) on the piano keyboard has been indicated,
23800 since the wave form includes only the 10th, 12th and 16th harmonics,
23900 the notes middle C, Eb and G will be heard.
24000
24100 Several experiments with different wave forms should be made. Be
24200 sure to SEE the waves so a visual-aural connection might be made.
24300
24400 A function may be changed in the middle of a PLAY routine but it must
24500 be noted that the new wave definition must follow! the note which it
24600 is to affect.
24700
24800 In PLAY;SIMP 0 .3 D 1000; SIMP .3; SYNTH(F1); 1,.7 3,.2
24900 5,.1 999; SIMP .6,,E; FINISH; the newly defined wave
25000 will be heard in the second and third notes.
25100
25200
25300 If you wish to have several functions with different names available
25400 and you do not create them with the FUNC program, their names must be
25500 "declared" to MUS10. Suppose you wish to have F2, F3 and F4. You
25600 must type directly to MUS10 (or into an EDIT file which will be read
25700 by MUS10) the following:
25800
25900 ARRAY F2,F3,F4(512);
26000
26100 The "(512)" indicates that each function array will require 512 words
26200 of storage.
26600
26700 The following example will play a sequence of notes wherein are heard
26800 the 10th, 14th and 18th harmonics of a low C, then the 10th, 13th and
26900 16th, and finally the 10th, 12th and 14th harmonics.
27000 As each SYNTH function is typed in the wave will be
27100 displayed (at some terminals.) If you wish a clear screen after the
27110 last one has appeared, hit the 'ESC' key followed by a 'C'. (This is
27120 called ESCAPE C.)
27400
27500 ARRAY F2,F3(512);
27600 SYNTH(F1);10,1 14,1 18,1 999;
27700 SYNTH(F2);10,1 13,1 16,1 999;
27800 SYNTH(F3);10,1 12,1 14,1 999;
27900 PLAY;SIMP 0 .3 C/4 2000 F1;
28000 SIMP .3,,,,F2;SIMP .6,,,,F3;FINISH;
28100
28200
28300
28400 From this point on it would probably be better to prepare any
28500 input for MUS10 which requires more than a couple of lines of typing
28600 with the SOS or ETV editors. Typographical errors are inevitable and
28610 when an error is made near the beginning of a string of input typed
28620 directly to MUS10 you most likely will have to retype everything.
00100 A type of flow-chart diagram for SIMP would appear as follows:
00200
00300 P4 MAG*P3
00400 | |
00500 ↓ ↓
00600 ***************
00700 * * OSCIL
00800 * * U1 (UNIT GENERATOR ONE)
00900 * P5 *
01000 * *
01100 * *
01200 *********
01300 |
01400 ↓
01500 *****
01600 * OUT *
01700 * A *
01800 *****
01900
02000 The top left input, P4, serves simply as a multiplier for the numbers
02100 found in the wave form array, P5. The particular number from the
02200 array to be multiplied is determined by the number in the upper right
02300 input. The upper right input, in this case P3, when processed by
02400 "MAG" (the "magic" number) becomes the increment, the rate at which
02500 the wave form array is stepped through. The "magic" number is found
02600 by dividing the array length, 512, by the sampling rate, 12800 (for
02610 SPEED 1.)
02620
02800 512/SRATE=.04 (Higher sampling rates will be discussed later.)
02900
03000 The maximum size of the numbers in the wave array is + or -1. Thus
03100 if P4 is set to 1000 the output of the OSCIL will be numbers in the
03200 range +1000 to -1000 which will describe the wave form put into P5
03300 cycling at the rate given in P3.
03400
03500
03600 The code for entering this instrument follows:
03700
03900 INSTRUMENT SIMP;
04000 OSCIL(P4,MAG*P3,P5);
04100 OUTA←OUTA+U1;
04200 END;
04700
04800 This instrument has only one unit generator (the OSCIL) hence the
04900 output of U1 is added to the contents of OUTA. If there are several
05000 instruments the outputs of all the instruments will be combined in
05100 OUTA for each sample.
05200
05300 It will be noticed when playing instrument SIMP that the sound begins
05400 and ends quite abruptly. This is because no attack-decay envelope
05500 has been applied to the tone. The sound begins at the full amplitude
05600 of P4 and remains at that level for its total duration.
00100
00200 To apply an envelope, another unit generator must be added.
00300
00400
00500 P4 MAG/P2
00600 | |
00700 ↓ ↓
00800 ***************
00900 * * OSCIL
01000 * * U1 (UNIT GENERATOR ONE)
01100 * P5 *
01200 * *
01300 * *
01400 *********
01500 |
01600 | MAG*P3
01700 | |
01800 ↓ ↓
01900 ***************
02000 * * OSCIL
02100 * * U2 (UNIT GENERATOR TWO)
02200 * P6 *
02300 * *
02400 * *
02500 ********* INSTRUMENT TOOT;
02600 | OSCIL(P4,MAG/P2,P5);
02700 ↓ OSCIL(U1,MAG*P3,P6);
02800 ***** OUTA←OUTA+U2;
02900 * OUT * END;
03000 * A *
03100 *****
03200
03300 Now that the instrument has been expanded you will note that it is
03400 the output of unit generator two (U2) which goes to OUTA.
03500
03600 P5 will now contain the envelope array. This array is best defined
03700 by the SEG routine. SEG defines the positions of line segments used
03800 to approximate a curve. With SEG several pairs of numbers may be
03900 entered. The first number of each pair is an amplitude, normally in
04000 the range of 0 to 1, and the second is the step number in the array.
04010 The step numbers 1 through 100 are used in SEG. (However the step
04020 numbers are converted internally to 512 array locations.) Straight
04030 line segments are drawn between each of the points defined. The
04040 following would put a triangular envelope shape into F2:
04500
04600 ARRAY F2(512);
04700 SEG(F2); 0,1 1,50 0,100;
04800
04900 Note that the routine is terminated when step 100 is reached.
05000 DO NOT USE 999 with SEG.
05100
05200 After having typed in the code for instrument TOOT and the definition
05300 for an envelope in F2, the following will produce a note using that
05400 envelope:
05500
05600 SYNTH(F1);1,1 2,.4 3,.1 999;< Sets the tone color.
05700 PLAY;TOOT 0 .5 A 2000 F2 F1;FINISH;
05800
05900 If two envelopes are to be contrasted add another function and define
06000 it.
06100 ARRAY F3(512);
06200 SEG(F3); 0,1 1,7 .2,25 .1,60 0,100;< Staccato
06300 PLAY;TOOT 0 .2 1000 2000 F3 F1; < P5 has envelope
06400 TOOT .2 .5,,,F2;FINISH;<Plays stac. then sust.(F1 then F2)
06500
00100 In the next example a unit generator will be added above the right
00200 side of the bottom, tone producing unit generator. In this way a
00300 function may be used to describe fluctuations of pitch within the
00400 duration of a note -- much as the previous example gave the
00500 possibility for changing the amplitude during a single note.
00600
00700
00800 MAG*P7-MAG*P3 MAG/P8
00900 P4 MAG/P2 | |
01000 | | ↓ ↓
01100 ↓ ↓ ***************
01200 *************** * * OSCIL
01300 * * OSCIL * * U2
01400 * * U1 * P9 *
01500 * P5 * * *
01600 * * * *
01700 * * *********
01800 ********* MAG*P3 |
01900 | | _____________|
02000 |________ _↓___↓_
02100 | \ /
02200 | \ + /
02300 | \_/
02400 | |
02500 ↓ ↓
02600 ***************
02700 * *
02800 OSCIL * *
02900 U3 * P6 *
03000 * *
03100 * *
03200 ********* INSTRUMENT GLISS;
03300 | OSCIL(P4,MAG/P2,P5);
03400 ↓ OSCIL(MAG*P7-MAG*P3,MAG/P8,P9);
03500 ***** OSCIL(U1,MAG*P3+U2,P6);
03600 * OUT * OUTA←OUTA+U3; END;
03700 * A *
03800 *****
03900
04000
04100 In order for this instrument to perform glissandos, a third function
04200 must be defined for P9 (the "shape" of the glissando). A straight
04300 line slope will suffice for a simple glissando. After typing in the
04400 instrument definition set up the three functions.
04500
04600 ARRAY F5,F6(512); <F1 is already present.
04700 SEG(F5);0,1 .8,7 1,12 1,90 0,100;<Envelope
04800 SEG(F6);0,1 1,100; <Slope
04900
05000 In the preceding, the ARRAY declaration is needed only when some new
05100 function names are to be used.
05200
05300 The following will play a glissando up two octaves, from C to C*4.
05400
05500 PLAY; GLISS 0 1 C 2000 F5 F1 C*4 1 F6; FINISH;
05600
05700 If P8←.5; (while P2 remains at 1) two glissandos will be heard.
05800
05900
06000
06100 This instrument may be used for a dramatic demonstration of
06200 "foldover", the phenomenon which occurs when a frequency exceeds the
06300 upper limit of one half the sampling rate. (See Mathews' book for a
06400 technical explanation.)
06500
06600 For this purpose it is best to use a Sine wave in P6.
06700
06800 SYNTH(F1); 1 1 999;
06900
07000 PLAY; GLISS 0 1 1000 2000 F5 F1 4000 1 F6;FINISH;
07100
07200 This first note will slide up from 1000 hz to 4000 hz.
07300
07400
07500 PLAY; GLISS 0 1 1000 2000 F5 F1 11800 1 F6;FINISH;
07600
07700 Due to "foldover" (at 12800/2 hz.) this note will slide up to 6400 hz
07800 and return to the 1000 hz level even though 11800 hz was given in P7.
07900 The general rule for "foldover" is that any frequencies which exceed
08000 one half the sampling rate will be heard at (SRATE-F) hz.
08100
08200
08300 Try this one!
08400
08500 PLAY; GLISS 0 1 0 2000 F5 F1 30000 1 F6; FINISH;
08600
08700
08800 This same instrument may be used to produce a vibrato by putting a
08900 sine wave into P9, setting P8←1/7; (the vibrato rate will be 7 times
09000 per second) and making P7 some very small amount different from P3.
09100
09200 PLAY; GLISS 0 1 C 2000 F5 F1 C+2 1/7 F1; FINISH;
09300
09400 (It is assumed that F1 is a sine wave.)
00100 Various types of noise and other random fluctuations are
00200 produced by the two random number unit generators. These are called
00300 RANDH and RANDI. RANDH (H=hold) produces in effect a function made
00400 up of horizantal lines at various levels with a perpendicular jump
00500 from one level to the next. There are two inputs to RANDH. The
00600 first (left hand) gives the range, plus or minus, of random
00700 selection and the second (right hand) gives the rate (per second) at
00800 which the selections are to be made.
00900
01000 Care must be taken with the number in the first input. If
01100 the number 100 is given, the output of RANDH will fluctuate between
01200 +100 and -100. Thus if a range of 100 to 200 is desired, the input
01300 number should be 50 and the number 150 must be added to the output.
01400
01500
01600 MAG*P7 MAG*P8
01700 P4 MAG/P2 | |
01800 | | ↓ ↓
01900 ↓ ↓ ***************
02000 *************** * *
02100 * * OSCIL * RANDH * U2
02200 * * U1 ***************
02300 * P5 * |
02400 * * |
02500 * * |
02600 ********* MAG*P3 |
02700 | | _____________|
02800 |________ _↓___↓_
02900 | \ /
03000 | \ + /
03100 | \_/
03200 | |
03300 ↓ ↓
03400 ***************
03500 * *
03600 OSCIL * *
03700 U3 * P6 *
03800 * *
03900 * *
04000 ********* INSTRUMENT NOISE;
04100 | OSCIL(P4,MAG/P2,P5);
04200 ↓ RANDH(MAG*P7,MAG*P8);
04300 ***** OSCIL(U1,MAG*P3+U2,P6);
04400 * OUT * OUTA←OUTA+U3; END;
04500 * A *
04600 *****
04700
04800 ARRAY F2(512); <F1 is already present.
04900 SEG(F2);0,1 .8,7 1,12 1,90 0,100;<Env.
05000
05100
05200
05300
05400 The following will produce white noise.
05500
05600 SRATE←25600;MAG←512/SRATE;
05700 PLAY;NOISE 0 .5 C*8 1000 F2 F1 P3 P3*4;FINISH;
05800
05900 Actually P8 (given as P3*4) can probably be left at a number
06000 like 4000 for noise purposes. As P7 is changed the apparent
06100 band-width of the noise will be changed. As the band-width gets
06200 narrower the center frequency becomes more apparent. Thus if P7←P3/16
06300 and P3 is up in the range of C*8, something of the effect of blowing
06400 across an open tube will be produced. The pitch is clear -- but
06500 quite windy.
06600
06700 The SRATE (sampling rate) must be increased for noise
06800 production since very high frequencies are essential. At SRATE←25000
06900 the high frequency cut-off will be at 12800 hz.
07000
07100 If P8 is set to a low number (e.g. 8) individual random
07200 pitches, instead of noise, will be produced at that rate.
07300
07400
07500 If the random unit generator is replaced by a RANDI the
07600 random function produced will be made up of a series of slopes
07700 (I=interpolating) up and down from one random point to another. In
07800 the case of noise production there is little difference between RANDI
07900 and RANDH. However RANDI is necessary for getting such things as
08000 random vibrato. The following will produce an acceptable, "human"
08100 sounding vibrato.
08200
08300 PLAY; NOISE 0 1 C*2 1000 F2 F1 P3*.01 16; FINISH;
08400
08500 The random rate of 16 per second (in P8) is considerably
08600 faster than the human vibrato rate of 5 to 8 per second. In this
08700 case however since the full band-width (in P7) is only seldom
08800 attained and the heard effect is that of a rate much slower than 16.
00100 Frequency modulation allows for the production of a wide
00200 variety of tone colors using relatively little compute time. The
00300 INTRP unit generator is really just a combination of an OSCIL and an
00400 ADD box. The left input represents the output when the function (P10
00500 below) is at zero and the right input represents the output when the
00600 function is at 1 (peak amplitude). No time input is given with
00700 INTRP. The speed of stepping through the function array is always
00800 taken as being P2, i.e. the note duration. In this case P10 will
00900 contain an envelope which will control the changes in frequency
01000 modulation. For a full explanation of FM see John Chowning's AES
01100 Journal article on this subject.
01200
01300
01400 P9*P7*MAG P8*P9*MAG
01500 | |
01600 ↓ ↓
01700 ***************
01800 * *
01900 * P10 * INTRP
02000 * * U2
02100 * *
02200 * *
02300 * *
02400 * P9*MAG
02500 P4 MAG/P2 | |
02600 | | ↓ ↓
02700 ↓ ↓ ***************
02800 *************** * * OSCIL
02900 * * OSCIL * * U3
03000 * * U1 * P11 *
03100 * P5 * * *
03200 * * * *
03300 * * *********
03400 ********* MAG*P3 |
03500 | | _____________|
03600 |________ _↓___↓_
03700 | \ /
03800 | \ + /
03900 | \_/
04000 | |
04100 ↓ ↓
04200 ***************
04300 * *
04400 OSCIL * *
04500 U4 * P6 *
04600 * *
04700 * *
04800 ********* INSTRUMENT FM;
04900 | OSCIL(P4,MAG/P2,P5);
05000 ↓ INTRP(P7*P9*MAG,P8*P9*MAG,P10);
05100 ***** OSCIL(U2,P9*MAG,P11);
05200 * OUT * OSCIL(U1,U3+P3*MAG,P6);
05300 * A * OUTA←OUTA+U4; END; FINISH;
05400 *****
05500
05600
05700
05800 The following functions should be set up to test the FM instrument.
05900
06000 ARRAY F1,F2,F3(512);
06100 SYNTH(F1); 1 1 999; < A sine wave.
06200 SEG(F2);0,1 .9,4 1,8 1,72 .8,88 .5,95 0,100; < Envelope
06300 SEG(F3); 0,1 1,100; < An upward slope or ramp.
06400
06500 The following will produce a shift from a pure sine tone to a
06600 highly modulated tone over a period of 2 seconds.
06700
06800 PLAY; FM 0 2 100 1000 F2 F1 0 10 100 F3 F1; FINISH;
06900
07000
07100 To reverse the procedure, i.e. change from the modulated tone
07200 to the pure tone, reverse the values of P7 and P8.
07300
07400 P7←10; P8←0; PLAY;FM;FINISH;
07500
07600
07700 Change F3 (the ramp) to make the modulation emerge only in
07800 the mid-part of the note.
07900
08000 SEG(F3); 0,1 1,50 0,100; < Makes a pyramid.
08100
08200 PLAY;FM;FINISH;
08300
08400 Try several of the variations suggested in Chowning's article.
00100 ********** APPENDIX XXX NOT COMPLETE!!!XXX ************
00200
00300 The main program for sound generation is currently called MUSIC.FAI
00400 or some similar name. The export version is designed to run on
00500 a standard PDP10 DEC system (which has a "FAIL" compiler.)
00600
00700 The main program must be loaded with two subroutine packages which
00800 are called MUSF4.F4 (OR MUSEXP.F4) and MUSIO.FAI (or EXPIO.FAI.) The
00900 FORTRAN routines are for the creation of function arrays and for
01000 organizing the output of sound samples to tape or disk after they
01100 have been computed. The FAIL routines are for fast output of blocks
01200 of samples.
01300
01800 See SCORE.LCS[UP,DOC] for information on longplaying features (RCDFLG
01900 and BIGBIT) and much other information.
02000
03400
03500
03600
03700 ************ LOCAL SPEAKERS ***********
03800
03900
04000 To hear all sounds produced by the D-A converter from the
04010 small speaker associated with your TTY console hit the 'ESC' key
04020 followed by the '3', and then the 'U'. (ESCAPE 3 U).
00100 ********* SOME INFO RE. THE 'FUNC' PROGRAM ***********
00200
00300 CRUNCH: Any two functions already in a single .DAT file may be
00400 "crunched" together. Also, a function may be created by either the
00500 SEG or SYNTH routines and then if instead of typing "F" for FINISH
00600 the letter "Z" is typed the program will jump immediately to "crunch"
00700 mode. At this point the new function may be combined with any
00800 function found in the file presently in core. Note however that once
00900 this new function is processed by any of "crunch" options its
01000 original form cannot be regained without going back to ordinary SEG
01100 or SYNTH mode.
01200
01300 PLOTTING: If "SP" (=see on the plotter) is typed single functions
01400 can be drawn on the Calcomp plotter. The size asked for is in
01500 inches. "SA" (=see all on plotter) will plot all the functions found
01600 in a single file. "SX" (=see all on the XGP) will draw all functions
01700 from a single file in the proper size for printing by the XGP. In
01800 order to use "SX" you must!!! follow the next steps exactly!!!
01900
02000 Before running FUNC type: A DSK PTP <CR>. This will cause the
02100 instructions FUNC sends to the plotter to be written in a
02200 file on the disk.
02300
02400 When the FUNC program finishes then type R X <CR>.
02500 This runs a program called X which converts plotter
02600 information to XGP commands.
02700
02800 X will ask you 5 questions. You should answer as follows:
02900
03000 PLOT.BIN <CR> (the file name)
03100 <CR> (plot slice?)
03200 5 <CR> (shift 5 inches)
03300 <CR> (use default value of 11".)
03400 1 <CR> (1 inch from the left)
03500 Y (yes, delete the plot file)
03600
03700
03800
00100 Information re. WAVES. To run it type R WAVES.
00200
00300 This will allow you to display the actual wave shapes of sound
00400 computed using RCDFLG←-1;. The MUSAA.DMD file thus produced is read
00500 by WAVES.
00600
00700 You may display up to 3072 samples at a time but since only 1024
00800 separate positions can be shown at once, larger numbers will cause
00900 some samples to be skipped over (but with no great loss.) After each
01000 group of samples is displayed a <CR> will move on to the next group.
01100 If a number is typed, that will set the extent of the next group. If
01200 the number -1 is given, the program will automatically cycle through
01300 all available samples by groups of the last given number. (When no
01400 more samples are to be found it will end with an error message.) In
01500 order to make the program go backwards type any number less than
01600 -2 for the number of samples you wish to back up.
01700
01800 This program should be of use in seeing the wave shapes produced by
01900 amplitude and frequency modulation as well as seeing the effects of
02000 foldover, etc. Composite waves from more than one voice may be
02100 displayed but as the complexity increases it may prove rather
02200 difficult to glean useful information from what is seen.