Oh how I loved to play around with the contrast and brightness controls – and it was just so intuitive. Today no computer screen I know has extra buttons to control brightness and contrast – but back in the days, at least the screen of the IBM PC had this basic set of controls.
![IBM PC Brightness Contrast Controls IBM PC Brightness Contrast Controls](https://www.bilderbook.org/wp-content/uploads/2020/11/IBM-PC-Brightness-Contrast-Controls-DSCN7561-800x600.jpg)