Prime Sieve in Action created with LOGO

TO primes
cs ht pu
setpc 4
setxy -85 220 PD label [Prime Sieve]
setpc 1
prntarray 2
sieve 2 2
sieve 3 3
sieve 5 5
sieve 7 7
sieve 11 11
sieve 13 13
END

TO prntarray :n
if :n > 200 [stop]
pu setxy calcx :n calcy :n pd
label :n
prntarray :n + 1
END

TO sieve :n :i
if :i * :n > 200 [stop]
setpc 4
pu setxy calcx :i * :n calcy :i * :n
pd label :n * :i sound list :n * 80 80
setpc 15 label :n * :i
sieve :n :i + 1
END

TO calcx :n
make "x (4 * remainder (:n - 1) 10)
if :n < 10 [make "x :x + 1]
if :n < 100 [make "x :x + 1]
op 10 * :x - 220
END

TO calcy :n
make "y (int (:n - 1) / 10)
op 180 - 20 * :y
END