60 READ B ( Read. .ecand numbe, In line 110 DATA.
70 IFB= -lTHENEND ( ,ENDSwhenI.REAo.-1 In line 900.
80 POKE 54273,A: POKE54272, B '(-POKE. 'he.fi... numbed,omDATAInline110(A= 17)
as HIGH FREQUENCY and second numb.r (8=37)
as LOW fREQUENCY. Next time program loops
around it READS A as 19 and B as 63, and so on,
and POKEsthese numbers into the HIGH and LOW
fREQUENCY locations. The number ~4273=HIGH
FREQUENCY fo, VOICE I and 54272=lOW FRE-
QUENCY fo, VOICE I.
85 POKE 54276, 17 ( Sta" nole.
90 FORT=1T0250:NEXT:POKE54276,16 let It play then $lop note
95 FORT=lT050:NEXT( Time fo, ,.1.0...
100 GOT020 ( .loop. back to ,e..' CONTROLoed play new note.
110 IDATA 17,37,19,63,21,154,22,227 Mu.lcal note valued'om no'e value chart InAppendix
120 DATA'25,177,28,214,32,94,34, 175 M. Each pal, of numbe.. ,ep,e.enls one note. Fa,
eJlomple. 17 and 37 represent "C" of the Ath DC-
toye, 19 and 63 repr.sent "0" and so on.
900 DATA-l,-l<,
When program reaches -1 it turns oH HIGH/LOW
FREQUENCY se"ing' and ENOs as instructed in
line 70.
To change the sound to a "harpsichord," change Line 85 to read
POKE54276,33 and Line 90 to read FORT=1T0250:NEXT:POKE54276,32
and RUN the program again. (Tochange the line, hit the 1:1.111''''1111:.11key
to stop the program, type the word LISTand hit .:4;11I1111_,then retype
the program line you ""';'antto change; the new line will automatically
replace the old one). What we did here is change the "waveform" from
a "triangular" shaped sound wave to a "sawtooth" wave. Changing the
WAVEFORM can drastically change the sound produced by the COM-
MODORE 64 . . . but. . . waveform is only one of several settings you
can change to make different musical tones and sound effects! You can
also change the ATTACK/DECAYrate of each note. . . for example, to
change from a "harpsichord" sound to a more "banjo" sound try chang-
ing lines 20 and 30 to read:
20 POKE54277,3
30 POKE54278,0 <'
Sets no sustoin for bonjo effect.
82
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