1. Synonym slap on the side. Especially used of add-ons for the late and unlamented IBM PCjr.
2. The IBM PC compatibility box that could be bolted onto the side of an Amiga. Designed and produced by Commodore, it broke all of the company's own design rules. If it worked with any other peripherals, it was by magic.
[Jargon File]
two-wheeled, open vehicle, popular in Ireland from the early 19th century. It was unusual in having lengthwise, back-to-back or face-to-face passenger seats. The light, horse-drawn cart carried four passengers (although the earliest versions carried more). It usually had a narrow, forward-facing driver's seat