CGAify

A little utility that takes an image and produces a reduced version of it compatible with old CGA, EGA, and VGA graphics modes.

Example

Original:

As CGA 4-color:

As EGA 16-color:

As VGA 256-color:

Status

The supported modes are:

• CGA 320x200 4-color
  • Palette 0 (Black, Red, Green, Yellow)
  • Palette 1 (Black, Magenta, Cyan, White)
• EGA 320x200 16-color default palette
• EGA 640x350 16-color default palette
• VGA 320x200 256-color default palette

When reducing the size, the aspect ratio is preserved.

Note that this is just for fun/nostalgia, and not to make images for viewing on actual old-school CGA screens... for that, I'd need to adjust for the aspect ratio of rectangular 80's pixels versus the square pixels of today.

Installation

go install github.com/rwtodd/Go.Cgaify/cmd/cgaify@latest

Giving -h will give usage information.

Installation: step by step

• install go(lang) https://go.dev/doc/install
• install cgaify (go install github.com/rwtodd/Go.Cgaify/cmd/cgaify@latest)
• go to $GOPATH/bin where cgaify is installed (you can check GOPATH value by doing go env)
• run ./cgaify -h to see options. ./cgaify -m CGA1 $PATH_TO_REPO/example/example.jpg
• Image example.jpg_CGA1.gif will be generated in this directory