In the past few years, we have covered plenty of fancy chess computers. The Conic Computer Chess is a classic one from 1979. It has a F8 (Mostek 3850) processor with 1 Mhz speed and 256 bytes RAM. You can power it with a 9V adapter or batteries.
This chess computer doesn’t have a board attached. It has a bunch of buttons to enter the moves. It has 5 levels for you to chose from.