Microchip revolution

The microchip revolution was a technological revolution which occurred on Earth in the early 1980s, leading to the creation of devices such as a tape deck carried by Ace. Pleased to see that her tape deck had been destroyed by an Imperial Dalek after she had took it with her to Shoreditch in November 1963, the Seventh Doctor explained that if someone had found that "dangerous anachronism" and discovered the principles of its function, the microchip revolution would begin twenty years too early and cause "incalculable damage" to the timeline. (TV: Remembrance of the Daleks)