lptest —
generate lineprinter ripple pattern
lptest writes the traditional "ripple test"
  pattern on standard output. In 96 lines, this pattern will print all 96
  printable ASCII characters in each position. While originally created to test
  printers, it is quite useful for testing terminals, driving terminal ports for
  debugging purposes, or any other task where a quick supply of random data is
  needed.
The length argument specifies the output
    line length if the default length of 79 is inappropriate.
The count argument specifies the number of
    output lines to be generated if the default count of 200 is inappropriate.
    Note that if count is to be specified,
    length must be also be specified.
lptest appeared in 4.3BSD.