How classic Sierra game graphics worked (and an attempt to upscale them)

Robin Ward (eviltrout) explains how the background graphics in classic Sierra adventure games were stored and drawn, and shows his attempt to upscale them. The games used vector-style drawing rather than plain bitmaps, which makes higher resolutions possible.

HN people share it as the explanation behind a tool that renders and upscales Sierra backgrounds, and cite it for the fact that the games used vector graphics.

“The Sierra Adventures used vector graphics, so it's possible to render them in higher resolutions”