Epson HX-20

The personal computer has become wearable. There are very compact instruments, light, refined in both design and materials. Today we use smartphones, or tablet devices like iPad or the most varied, by shapes and sizes, running Android. If we are a bit more demanding we opt for a netbook or a “classic” notebook.
Today we take for granted that there are these little gems, but how this category of devices had its origin?
It was, needless to say, groundbreaking '80s. The very first device, which actually created this segment, was produced by Epson in 1983, and was called HX-20.

The Epson HX-20 was simply revolutionary. A light computer, equipped with a LCD display capable of displaying text on 4 rows and graphics on a matrix of 120×32 pixel.
On the right side was possible to install a microcassette unit, such as voice recorders so dear to journalists and students of the time, on which it was possible to store data and programs, while on the left side, it had a dot matrix microprinter, in all respects similar to those mounted on the office calculators or on cash registers, also modern ones. The Epson HX-20's printer was capable of printing up to 17 characters per second. 🙂

Weighed only 1,6 Kg, was as big as an A4 sheet, and was supplied in a handy hard case, which served as a protective shell and carry bag. Furthermore, it provided a mechanical keyboard, of high quality, coming with a pleasing touch and well-matched colors.

The Epson HX-20 was not only the world's first fully portable system, it was also one of the first home/personal systems with two processors operating in parallel, by splitting functionality and memory areas.
It was a pair of Hitachi 6301 (variants of the Motorola 6300), operating at 0.7 MHz each, in MASTER / SLAVE mode.
The on-board RAM was 16KB of memory, expandable to 64KB. Into its ROM, of 32KB, along with a monitor and fonts, was stored the inevitable BASIC interpreter, produced by the inevitable Microsoft. 🙂

The Epson HX-20 of my collection was purchased on ebay as “not working”. Obviously, as a good passionate collector, I opened it and tried to see what was wrong. The problem was in the battery pack, irreparably damaged, and internally short-circuited. After removing the battery pack terminal, and connected to the wall power plug, the little monster has issued its BIP, filling my heart with joy.

The battery pack can be reproduced today, putting in series two pairs of common Ni-Cd cells that, once fully loaded, provide up to 50 hours of autonomy to the machine. Yes: Fifty hours of battery life. 🙂
Unfortunately I have not had time to create the package parts, since I had to move to another city to avoid losing my job, leaving the PC in question, along with my collection, in my empty house. 🙁


  1. Hello,

    Quite a few HX-20s still about, and turning up on the second hard market.
    I purchased mine 1983 when it first came out, and it’s still working. Struggling a little, mind you. Now using external battery, and I connect audio to laptop to operate SAVE/LOAD, and use the hxtape process to change between .WAV and .TXT/.BAS. Collecting some older software for the machine, watching for new developments (yes, there are some!)

    Best wishes to all HX users. Geoff, Guisborough, England

  2. I was trying to find a copy of the game illustrated on a YouTube video, BOMBER (but game is more correctly BLITZ) by Simon Taylor. No luck, until I tracked down Simon Taylor himself, who had a cassette with the game on, but he could not read the file any more. Simon kindly loaned me the tape, and we were able to ‘recover’ the file with help from Audacity, and it’s now available as a .WAV.

    The link below is to a website about the HX-20, and includes details of the recovery process, and a link to the .WAV file


Leave a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.