Epson HX-20

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The Epson HX-20 (also known as the HC-20) was an early laptop computer, announced in November 1981, although first sold widely in 1983. Hailed by BusinessWeek magazine as the "fourth revolution in personal computing", it is generally considered both the first notebook and handheld computer and it is for this reason that it is highly prized among collectors.

With about the footprint of an A4 size page, the Epson HX-20 features a full-transit keyboard, rechargeable nickel-cadmium batteries, a built-in 120 × 32-pixel LCD display (smaller than that on many mobile phones today), a calculator-size dot-matrix printer, the EPSON BASIC programming language, expandable RAM and a built-in microcassette drive. It uses a proprietary operating system, which consists of the Epson Basic interpreter and a system monitor program, and weighs approximately 1.6 kg. Known colours of the machine are silver and cream, while some prototypes were dark grey. The HX-20 was supplied with a grey carry case. An external acoustic coupler, the CX-20, was available for the HX-20, as was an external floppy disk drive, the TF-20, and an external speech synthesis Augmentative Communication Device (ACD), ‘RealVoice’. The battery life of the HX-20 was approximately 50 hours.

The later, more popular TRS-80 Model 100 line, designed by Kyocera, owed much to the design of the HX-20.

[edit] Similar Epson models

Epson HX-20 promotional free booklet distributed in Taiwan

HC-80
HC-88
HX-20
HX-40
HX-45
KX-1
PX-16
PX-4
PX-8
QX-10, QX-16
EHT-30, EHT-40

[edit] Problems

A common complaint found in most HX-20 computers today is the failure of the internal Ni-Cd rechargeable battery pack. The battery pack is easily replaced by a NiMH (or equivalent) battery pack. Changing the battery pack is not generally considered to reduce the collectible value of the computer, as doing so does not damage any internals.

An easy fix for replacement batteries is to use four AA cells in a holder secured on the inside. The leads can be easily soldered on to the connector from an original battery.