A wave function in nested loops written in BASIC on a Sinclair ZX Spectrum 48k (Fuse Emulator) showing dissonant and resonant sine waves.
100 REM listing
304 LET a=25: LET h=128 : REM harmonic
400 FOR i = 0 TO 6
410 GO SUB 510: LET h=h-10
420 NEXT i: GO TO 1000
510 FOR x = 0 TO 255
515 LET y=88+a*SIN(x/h*PI)
520 PLOT x,y+47
530 NEXT x: RETURN
400 FOR i = 0 TO 6
410 GO SUB 510: LET h=h-10
420 NEXT i: GO TO 1000
510 FOR x = 0 TO 255
515 LET y=88+a*SIN(x/h*PI)
520 PLOT x,y+47
530 NEXT x: RETURN
1000 STOP
