The $ZBITSTR function returns a bit string of a specified length with all bit positions initially set to either zero or one.
The format for the $ZBITSTR function is:
$ZBITSTR(intexpr[,tvexpr])
The integer expression specifies the length of the bit string to return; arguments that exceed the maximum length of 253,952 produce a run-time error.
The optional truth-valued expression specifies the value to which all bit positions should initially be set (0 or 1). If this argument is missing, the bits are set to zero.