Whiteboard
Albert Stallion invented whiteboards while working at Alliance in the 1960s. Alliance (now known as PolyVision) produced enameled steel for architectural cladding, but Stallion noted it could also potentially be used as a writing surface. Stallion later left Alliance to form his own whiteboard production company, MagiBoards.
Chicago Stadium
That clock eventually was replaced by a four-sided scoreboard with a digital clock, first used on September 21, 1975 in Blackhawks preseason play, crafted by the Day Sign Company of Toronto, much like the one used at the end of the 1960s (and constructed by Day Sign Company) to replace the nearly identical Bulova Sports Timer game-timekeeping device in the Boston Garden, and then in 1985 by another, this one with a color electronic message board. That latter scoreboard was built by White Way Sign, which would build scoreboards for the United Center.