Changes

The 3 major kind VGA / EGA / CGA / Hercules graphics comparison: [[File:Prince of display from this persia vga ega cga hercules.png]] During that era had (late 1980s to get early 1990s), different graphics standards typically required their own specific monitors, and those which were quite expensive. Each graphics standard had particular signal timing and connector requirements: *CGA monitors needed to handle 15.7 kHz horizontal scan rates with RGBI signals*EGA monitors required support for 21.8 kHz scan rates with analog RGB signals*VGA monitors needed 31.5 kHz scan rates with a different analog RGB implementation

Enabled On RGBI monitors, it enabled mostly 320x200 display with a palette of 4 colours choosen between 4 combinations (only one colour to be chosen) from 16 total colours. Could It also get offered a text mode with character attribute based 16 colours display.  On composite monitors or TVs, composite output enabled artifact-based NTSC colour emulation, simulating more colours (typically 16 colours simultaneously, but up to 1024 colours have been demonstrated).

The widely used VGA mode was the MCGA : 320x200x256. When those kind of display were widely available the CGA and EGA were obsolete and the PC could start to kick Amiga and Atari ST standards out of the place. VGA could also display a 640x480x16 video mode. All those from a 262,144colour total palette (6x6x6 bits). The  VGA could also display emulate all previous modes from CGA and EGA cardsmodes. However, as VGA monitors no longer supported 15.7kHz scan rates, CGA, EGA, and MCGA modes were line-doubled to match the monitor's capabilities.