6.1.1540
FILL
 
CORE
 
( c-addr u char -- )

If u is greater than zero, store char in each of u consecutive characters of memory beginning at c-addr.

Testing:
T{ FBUF 0 20 FILL -> }T
T{ SEEBUF -> 00 00 00 }T

T{ FBUF 1 20 FILL -> }T
T{ SEEBUF -> 20 00 00 }T

T{ FBUF 3 20 FILL -> }T
T{ SEEBUF -> 20 20 20 }T