In 1964, Donald Bitzer invented the plasma display for UIUC’s PLATO system because cathode ray tubes required external computer memory to refresh the screen 30 times a second—an unbearable cost when memory was priced by the byte. Plasma’s bistable gas discharge cells acted as their own physical memory elements, eliminating the refresh bandwidth bottleneck. Once DRAM rode Moore's Law down the cost curve, the core economic reason for plasma vanished, leaving it to fight LCDs solely on picture quality until LCD manufacturing scale and yield learning curves wiped it out. construction-physics.com