Seiko Epson
HX-20
Provisional entry — research in progress
This page was generated automatically from cited public sources and hasn't completed the full research pass yet. Every specification shown carries its source; more detail is added as research completes.
The Seiko Epson HX-20 is a microcomputer introduced in 1982. The HX-20 is widely recognized as the world's first notebook computer.[1]
Plate 01EPSON HX-20 Quick Review
Capó's TechWatch on YouTubePlate 02The Story of the Epson HX-20 The Most Important Computer You’ve never heard of - Tech Retrospective
Newsmakers TechWatch on YouTubePlate 03The World's First Laptop - Epson HX-20 / HC-20
The Retro CollectiveWatch on YouTubePlate 04Epson HX-20 - Short Demonstration
Andi’s Retro MuseumWatch on YouTubePlate 05The RealVoice of the Epson HX-20
Michael WesselWatch on YouTubePlate 06The Epson HX-20 Demo
Chainsaw1972Watch on YouTubePlate 07Epson HX-20 #2 Microcassette refurb, Expansion Unit overview, testing things out.
Hey Birt!Watch on YouTube
What it is
How it works
The HX-20 has a built-in LCD screen, printer, and cassette player. The HX-20 has a full-size keyboard, a built-in 120 × 32 pixel LCD screen, a small dot-matrix printer, and a microcassette recorder for storing programs and data. The HX-20 runs on two Hitachi HD6301 single-chip microcomputer units. Both processors run at 614 kHz. The display offers a choice between MONITOR and BASIC after power on. MONITOR provides direct access to memory, and BASIC provides access to the built-in Microsoft BASIC interpreter.[2][3]
The HX-20 includes an RS-232 port and a high-speed serial port at the rear. The high-speed serial port can be used for a video display unit or a floppy disk drive. User programs can be stored on a micro cassette drive, an internal ROM socket, an external ROM cartridge, or an external floppy disk drive. The official memory expansion increased RAM from 16 kByte to 32 kByte.[3][5]
Applications
The HX-20 was used in professional applications and turn-key solutions. The HX-20 became a popular device in machine control and turn-key solutions. A book published in 1984 presented tax calculation programs that run in the basic version of the Epson HX-20.[3][6]
- microcomputer
What do the numbers mean?
Wafer handling1
Control & software3
Dimensions & facilities1
Configuration & options6
Vintage & configurations
- 1982Production start[1]
Epson entered the microcomputer market with the HX-20 in 1982.
What replaced it?
Related models
- successorSeiko Epson QX-10— Epson entered the microcomputer market in 1982 with the HX-20 before entering the home computer market with the QX-10.source[1]
Where are the manuals?
Generated from public-source data on file. Enter your email to access — nothing is published; details are routed privately.
Not publicly documented
Field notes
No research found yet — worked with this tool? Share what you know.
Frequently asked questions
What kind of device is the Seiko Epson HX-20?
The Seiko Epson HX-20 is a portable computer produced by Seiko Epson. The HX-20 was introduced in 1982, and it was originally known in Japan as the HC-20.[2][4][3]
What integrated features does the HX-20 include?
The HX-20 includes a built-in LCD screen, printer, and cassette player. The HX-20 also has a full-size keyboard and a microcassette recorder for storing programs and data.[2][3]
What processors does the HX-20 use?
The HX-20 runs on two Hitachi HD6301 single-chip microcomputer units. One processor is the main CPU and the other is the slave. Both processors run at 614 kHz.[2][3]
What operating environments are available after startup?
After power on, the HX-20 display offers a choice between MONITOR and BASIC. MONITOR provides direct access to memory, and BASIC provides access to the built-in Microsoft BASIC interpreter.[3]
How can programs and data be stored on the HX-20?
Programs and data can be stored on the micro cassette drive. User programs can also be stored or loaded by means of an internal ROM socket, an external ROM cartridge, or an external floppy disk drive connected to the high-speed serial port.[3]
Not publicly documented
The following facts about the HX-20 are absent from this record as of this revision. First-hand knowledge or a citation closes a gap; every submission is reviewed before publication.
No publicly documented variants, configuration options, or revision breakpoints of the HX-20 are on record.
Answerable by: an OEM product catalog or an engineer who ordered or specified the tool
The control-system platform and OS era of the HX-20 are not on record.
Answerable by: an engineer who operated it or OEM installation records
No publicly documented failure modes or field errata for the HX-20 are on record.
Answerable by: a field service engineer, process engineer, or maintenance technician
The process node or technology generation of the HX-20 is not on record.
Answerable by: an OEM datasheet or a fab qualification report
No publicly documented compatible parts, consumables, or accessories for the HX-20 are on record.
Answerable by: an OEM parts catalog or a service engineer
No research found yet — worked with this tool? Share what you know.
Sources & citations
Sources (6)Every fact above is drawn from these public sources
- [1]en.wikipedia.org — en.wikipedia.orgen.wikipedia.org
- [2]deskthority.net — deskthority.netdeskthority.net
- [3]cryptomuseum.com — cryptomuseum.comcryptomuseum.com
- [4]HX-20 — Seiko Epson | Specs, Sourcing & Service | Waferpedia — waferpedia.comwaferpedia.com
- [5]The Epson HX-20 — vintagecomputer.netvintagecomputer.net
- [6]Steuerberechnung mit dem Epson HX-20 | Springer Nature Link — doi.orgdoi.org
Last updated Oct 16, 2026.