i got this from a car boot sale, around 1998-99, i can't remember how much i paid, but i'm sure it wasn’t much,
for it's time i would think it might of been one of the first laptops (or should i say a battery powered portable computer).
my HX-20 come with a Micro cassette recorder (for storing data) and a RAM Expansion Unit, it runs a basic programming language (Epson Basic), that is very much like Microsoft's QBasic and Visual Basic, that might explain the CopyRight of Microsoft & Epson (see last picture),
the battery in the HX-20 is a 4 C cell Ni-Cd pack = 4.8 volts (that is totally dead in mine), so i'm powering it of a 5 volt power supply, that seems to work fine.
the built-in printer still works, but the printer ribbon is falling apart, but luckily it turns out that the printer in the HX-20 was the same type that was also used in a lot of cash tills, so finding a replacement is easy (just look for "ERC-05", for the black ribbon), the paper is just standard cash till paper too.
here are some sites i've found on the Epson HX-20: