[NuttyBar]

I wanted to know if there has ever been a case where one has designed and/or created a fully-functioning computer(processor, memory, some form of screen display, and/or RAM)that is handheld and battery-powered(like a cheap version of a computer).

I want to know if it's ever been done and heard of officially(from scratch, meaning no pre-made parts were used, no "wiring" business ... all parts were developed manually and/or put together on a circuit board as well).

If this has never happened, is it legal to create one yourself and sell it, manufacture it, and/or get it copyrighted and patented?

I am talking no "major" OS here, no high-technology software, and no modern-age hardware.

Just one battery, one miniature processor at over 50MhZ a second, only about 8-28MB of RAM(no permanent memory storage), and a display device and adapters to blit just tiny applets made of 4 or 8-bit pixels(ones that are never stored to any disk drives, and that only run when the machine is on, and all data lost when off).

Something simple like that, doable by maybe one or two people manually and individually.

Has it ever been done ... and how hard would it really be to assemble all the parts?

PS: This is assuming the person(s) are very skilled in electronics(engineering, too, possibly), computer programming, technology, and hardware. Or at least somewhat skilled.