A portable personal computer whose size enables it to be held in one hand while it is operated with the other hand. A major difference between palmtop computers and laptop computers is that palmtops are usually powered by off-the-shelf batteries such as AA cells. Palmtop computers typically do not have disk drives; rather, their programs are stored in ROM and are loaded into RAM when they are switched on. More recent palmtop computers are equipped with PCMCIA slots to provide wider flexibility and greater capability. See also handheld PC, PCMCIA slot, portable computer. Compare laptop.
A class of portable computer that is smaller in size and lighter in weight than a full-sized laptop. Subnotebooks feature a reduced-sized keyboard and screen and often use an external floppy drive to save space and weight. Despite their size, subnotebooks retain all the functions of a full-sized portable computer.