There used to be small IBM PC compatible "palmtop" computers capable of running for many days on a pair of AA batteries. HP 200LX was pretty cool. I think it had 80C186 running at 10 MHz or thereabouts, with 1MB of RAM, monochrome graphic LCD and PCMCIA cards for storage. Norton Commander and Turbo C run on it without any problems.
There was also the HP 95LX with a smaller screen (40x16, 240x128), a 5.37 MHz NEC V20 CPU, and 512K or 1MB of RAM.
Also, the 100LX with monochrome CGA (80x24, 640x200), a 7.91 MHz 80186-compatible CPU, and 1MB or 2MB of RAM but the extra was used for file storage as drive C:.
The 200LX was the same as the 100LX but had newer software in ROM.
