The HP 200LX Palmtop PC (F1060A, F1061A, F1216A), also known as project Felix, is a personal digital assistant introduced by Hewlett-Packard in August 1994. It was often called a Palmtop PC, and it was notable that it was, with some minor exceptions, a MS-DOS-compatible computer in a palmtop format, complete with a monochrome graphic display, QWERTY keyboard, serial port, and PCMCIA expansion slot. Description Input is accomplished via a small QWERTY-keyboard with a numeric keypad, enclosed in a clamshell-style case, less than about 25% of the size of a standard notebook computer. The palmtop runs for about 30–40 hours on two size AA alkaline or Ni-Cd rechargeable cells and can charge batteries (both Ni-Cd and NiMH) via a 12 V DC wall adapter. The HP 200LX has an Intel 80186 compatible embedded central processing unit named "Hornet", which runs at ~7.91 megahertz (which can be upgraded or overclocked to up to 15.8 MHz) and 1, 2 or 4 MB of memory, of which 640 KB is RAM and the rest can be used for expanded memory (EMS) or memory-based storage space. After-market updates can bring the memory chips to up to 64 MB, which frees the PCMCIA slot for modem or ethernet card use. The Silicom, Accton 2212/2216, Netgear FA411, and Sohoware ND5120 network cards were compatible. Being IBM PC/XT compatible and running MS-DOS 5.0 from ROM, the HP 200LX can run virtually any program that would run on a full-size PC compatible computer as long as the code is written for the Intel 8086, 8088 or 80186 CPU and can run using CGA graphics. It can also run programs written for the 80286 CPU, provided they do not require the use of protected mode. It has a 16-bit PCMCIA Type II expansion slot that supports 5 V at 150 mA maximum, a SIR compatible infrared port and a full serial port (but with a proprietary mini connector for space constraint reasons). The built-in software suite runs from ROM and includes the Lotus 1-2-3 Release 2.4 spreadsheet, a calendar, a phone book, a terminal, Lotus cc:Mail and a capable scientific/business calculator (among other applications). With a large compactflash storage card and a serial mouse, even Microsoft Windows 3.0 can be run on the palmtop. Running Windows was limited by the hardware, and the maximum version that could be run was Windows 3.0 in Real Mode. However, Word 1.x and Excel