The HP 200LX (also known as Project Felix) is a palmtop computer introduced by Hewlett-Packard in 1994. It was notable that it was, with some minor exceptions, a 100% MS-DOS compatible computer in a palmtop format, complete with a monochrome graphic display, qwerty keyboard, serial port, and PCMIA expansion slot. It used a CGA 4 gray scale screen with 640x200 pixels. It could be used for eBooks using any available DOS compatible program.
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 to 40 hours on two size AA alkaline or Ni-Cd rechargeable cells and can charge batteries (both Ni-Cd and NiMH) via a 12V DC wall adapter. It uses an Intel 80186 (x86) processor and has 2 or 4 MB of memory, of which 640 KB is RAM and the rest can be used for expanded memory.
 Earlier versions
The HP 100LX was the immediate predecessor with 1 Meg of memory. The HP 95LX introduce the basic design in 1991. It was known internally as Project Jaguar. It had an Intel 8086 CPU, but was hampered in running DOS applications because of its quarter-CGA resolution LCD screen.