Benjamin Heckendorn hacked together a custom Atari 800 laptop. Here are some of the specs from his project description:
* Uses (what's left of) an Atari XE GS (Game System) the last model Atari 800 type computer from 1987.
* 8" TFT active matrix display
* Compact Flash "hard disk drive" utilizing MyDOS 4.53 for maximum drive size of 16 megabytes. Card is removable for swapping.
* Built-in NiMH battery pack and charger (uses external plug like a normal laptop) Also battery is removable from base as with most laptops.
* Full (Atari 800) sized keyboard
* Built-in Player 1 & 2 controls, plus joystick ports. Built-in joypads great for playing Robotron 2084!
* Brushed aluminum and wood grain everywhere! A weird combo style, sure, but I like it!
