#tone.bas
# example program for HotPaw Basic
#
f = 880.0
enb=0
draw -1
form btn 120,40,32,12,"up",1
form btn 120,60,32,12,"Play",1
form btn 120,80,32,12,"down",1
form btn 120,120,32,12,"Stop",1
form fld 40,40,40,12,".06",1
draw "delta", 10,40
draw "freq = ",10,60
while 1
y = asc(inkey$)
if y > 16 then end
if y > 0 then gosub h1(y)
if enb then sound f,500,3
draw a$, 40,60
a$=str$(f,8,2)
wend
end
sub h1(x)
d = val(s$(0))
if y=14 then f = f*(1+d)
if y=16 then f = f/(1+d)
if y=15 then enb = 1
return
run