A palmtop PC was an approximately pocket calculator-sized, battery-powered PC in a horizontal clamshell design with integrated keyboard and display. It could be used like a 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 pocket.
Palmtop PCs distinguish from other palmtop computers by utilizing a mostly IBM-compatible PC architecture and BIOS as well as an Intel-compatible x86 processor. Most 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, MINIX 2.0, Windows 1.0-3.0, or Linux.
Most palmtop PCs were based on a static hardware design for low power consumption and instant-on/off without a need to reboot. Depending on the model, the battery could power the device from several hours up to several days while running, or between a week and a year in standby mode. Combined with the instant-on/off feature, a battery would typically last from a week up to several months in practical use as PDA.
Palmtop computers were discontinued in late 2000's as all the manufacturers shifted to tablets.
Palmtop PCs include:
- DIP Pocket PC (DIP DOS 2.11, 1989)
- Atari Portfolio (DIP DOS 2.11, 1989)
- Poqet PC Classic (MS-DOS 3.3, 80C88, 1989)
- Poqet PC Prime (MS-DOS 3.3, 80C88)
- Poqet PC Plus (MS-DOS 5.0, NEC V30)
- ZEOS Pocket PC (MS-DOS 5.0, 1991)
- Sharp PC-3000 (MS-DOS 3.3, 1991)
- Sharp PC-3100 (MS-DOS 3.3, 1991)
- Hewlett-Packard 95LX (MS-DOS 3.22, NEC V20, 1991)
- Hewlett-Packard 100LX (MS-DOS 5.0, 80186-compatible HP Hornet, 1993)
- Hewlett-Packard Palmtop FX (MS-DOS 5.0, 80186-compatible HP Hornet, 1993)
- Hewlett-Packard 200LX (MS-DOS 5.0, 80186-compatible HP Hornet, 1994)
- Hewlett-Packard 1000CX (MS-DOS 5.0, 80186-compatible HP Hornet)
- Hewlett-Packard OmniGo 700LX (MS-DOS 5.0, 80186-compatible HP Hornet, 1996)
Some touch-screen computers may also be counted into this category:
- Hewlett-Packard OmniGo 100 (Datalight ROM-DOS+PEN/GEOS 2.1, NEC V30HL-compatible Vadem VG230, 1993)
- Hewlett-Packard OmniGo 120 (DOS+PEN/GEOS, NEC V30HL-compatible Vadem VG230)
- Sub-notebook, IBM- and x86- compatible, clamshell design, but larger than palmtop PCs
- Netbook, IBM- and x86- compatible, legacy-free, clamshell design
- Ultra-mobile PC, IBM- and x86- compatible, legacy-free, not necessarily clamshell design
- Palm-size PC, not necessarily IBM- and x86- compatible, various form factors
- Handheld PC, not necessarily IBM- and x86- compatible, various form factors
- Pocket PC, typically not IBM- or x86-compatible, various form factors