The Acer S1283 supports a maximum resolution of 1920 x 1200 (WUXGA). That's over seven times the resolution of a 640 x 480 (VGA) multimedia projector, which is the most common resolution supported by similar spec data projectors that have been around for around the same time as the S1283. This projector also supports a supported graphics resolutions of 1024 x 768 (XGA).
This projector's resolution (1920 x 1200 (WUXGA)) is actually the best supported resolution across all similar spec data projectors that have been around for around the same time as the S1283.
A 640 x 480 (VGA) supported graphics resolutions is the worst supported resolution across similar types of projector.