The Macintosh PowerBook Video Cable allowed PowerBook 100-series laptops to be connected to Apple monitors sold in the early 1990s. Both ends of the cable were Apple-proprietary.
This cable allowed users of the earliest PowerBook series, such as the PowerBook 160 with a grayscale-only display, to plug into a color Apple monitor and use the PowerBook with a color screen.
According to an Apple Support document, the cable supported a resolution of 832×624 and was compatible with the following laptops: PowerBook 1400-series, PowerBook 190-series, PowerBook 520-series, PowerBook 5300-series, PowerBook 540-series, PowerBook 550c [Japan Only], PowerBook 160/165/180, and PowerBook 165c/180c.
Source: Apple
