A Palmtop PC is an obsolete, approximately pocket calculator-sized, battery-powered computer in a horizontal clamshell design with integrated keyboard and display. It could be used like a modern subnotebook, but was light enough to be comfortably used handheld as well. Most Palmtop PCs were small enough to be stored in a user's shirt or jacket pockets.
Palmtop PCs distinguish from other palmtop computers by using a mostly IBM-compatible PC architecture, and BIOS as well as an Intel-compatible x86 processor. All such devices were DOS-based, with DOS stored in ROM. While many Palmtop PCs came with a number of PDA and office applications pre-installed in ROM, most of them could also run generic, off-the-shelf PC software with no or little modifications. Some could also run other operating systems such as GEOS, Windows 1.0-3.0 (in Real mode only), or MINIX 2.0.
