I think they used EBCDIC, not ASCII. Those aliens were definitely an IBM shop.
I think IBM was found to be the Nazgul (at least the lawyers cause they could darken the sky with them). Do Nazgul count as aliens?
"Not long ago, the Black Gate of Armonk swung open. The lights went out, my skin crawled, and dogs began to howl. I asked my neighbor what it was and he said, 'Those are the nazgul. Once they were human, now they are IBM's lawyers.'" (IBM is headquartered in Armonk, New York).