Karl Rossum was head of Cybertron and the creator of the supercomputer H.A.R.D.A.C.. The name was taken from the play R.U.R (Rossum's Universal Robots), its author Karel Čapek is credited with coining the word "robot" in 1921. Contrary to some fan belief, his name was not a corruption of crime boss Carl Grissom, although the names are strikingly similar.
Bruce Wayne once said that Rossum had taught him everything he knew about electronics, suggesting that Rossum was once a mentor to the young businessman.
Rossum went into semi-retirement after his daughter was killed in a car accident. In his grief, Rossum thought of making a "perfect" world populated by androids instead of humans, where such things would never happen. To that end, Rossum resumed active leadership of Cybertron and designed and built H.A.R.D.A.C., a prototype artificial intelligence capable of producing androids that could impersonate living people.
Midway through his scheme's execution, Rossum realized that what he was doing was wrong, and that H.A.R.D.A.C. had gone beyond his control. He tried to shut H.A.R.D.A.C. down, but was incapacitated and imprisoned along with James Gordon, Hamilton Hill, and Harvey Bullock. They were rescued by Batman and Barbara Gordon, and he helped them all to escape Cybertron's building before an explosion that destroyed H.A.R.D.A.C. Outside, Hill assured him that he would not be held responsible for his creation's actions.
Rossum retired to a farm outside Gotham, settling for a more pastoral life, though still attended by a host of his robotic creations, albeit ones that he was able to constantly watch. When the Batman android appeared begging for help at his farm, Rossum remained composed, seeing that it was H.A.R.D.A.C's persona and managed to convince him he was indeed a robotic memory, unlike many people who would panic.
He would appear much later in the series, working in an office dressed as he was when he headed Cybertron. It is unknown if he revived the company or engaged in a new pursuit, but was seen with small robots that resembled toys. He says that one of his earlier careers was helping to build part of a theme park for Grant Walker, and told Batman that when Victor Fries was broken out of Stonegate Penintentiary, it looked similar to a droid he had once built.
Abilities and Appearance
Rossum was a brilliant inventor and electronics engineer, with a particular fondness for robots designed for various purposes.
He wore old-fashioned clothes, including a bow-tie, and spoke with a Mid-Western accent, giving him a rustic, "hayseed" appearance that belied his vast technological expertise.
Rossum was voiced by William Sanderson, a well-known character actor. Sanderson had a small but memorable role as an inventor/scientist in Ridley Scott's science-fiction film Blade Runner, also about advanced androids that resemble humans. Sanderson also inspired the physical appearance of Dr. Rossum.