In my secondary school, we had two contiguous rooms with computers. One has the modern one, color screen with Windows 3.1 or something. The other room had the

In my secondary school, we had two contiguous rooms with computers. One has the modern one, color screen with Windows 3.1 or something. The other room had the old computers, a monochrome white monitor, perhaps an orange Hercules monitor and also the old green one. In the green monitor the phosphorus took a looong time to fade away. When you turn it off, you can still read the content of the screen for like five seconds.