Portable – **** THE HOMECOMPUTER GUY ****

Full speed null modem cable for EPSON HX-20

To transfer software for the EPSON HX-20 from the PC, a so-called null modem cable is required. These cables usually have 9 pin D-Sub connectors at both ends. Therefore it is necessary to cut such a cable in the middle to solder a round 8 pin DIN connector to the open end.

For the HX-20 there are basically two variants for a data transmission cable. The simple variant requires only 3 cable wires, but has the disadvantage that no handshake or data flow control is possible. Ergo, only a low transfer rate is possible. I already presented such a simple cable here some time ago.

Here I now describe the more complex variant of a null modem cable, which is also suitable for higher transmission rates with data flow control. This allows a much more stable connection between PC and HX-20.

Very special season greetings

The Verein zum Erhalt klassischer Computer (VzEkC – www.classic-computing.org) did a super nice Christmas campaign on the initiative of our member Helmut (axorp) by releasing a Christmas tree plug-in card for the C64 in the Classic-Computing Edition. He was supported by another member Andreas (shadow-asc).

EPSON HX-20: The first true laptop computer

The EPSON HX-20 was the first “true” laptop to hit the market in the early 1980s. With its dimensions of the size of a DIN A4 sheet and the built-in rechargeable battery, it was revolutionary at the time. It was easy to carry in any briefcase and could run for many hours without an external power supply.

EPSON HX-20 unleashed: More characters and graphics for the laptop

flashx20 by Norbert Kehrer extends the screen of the HX-20 and adds a floppy emulation.

The EPSON HX-20 was the world’s first real laptop in the early 80s. I have already presented this exceptionally interesting device in another article.

However, those who want to work longer or more seriously with the EPSON HX-20 will surely miss a decent screen the most. The 4 x 20 characters of the LCD quickly make you lose track when you have to deal with larger listings. In addition, the graphic capabilities of the LCD are very limited. Fortunately, Norbert Kehrer has a simple and very practical solution with his tool flashx20. It simulates an external monitor for the HX-20 on a standard PC under Windows. On top of that there is a helpful floppy emulation, with which it is possible to load HX-20 programs directly from the PC.

Data transfer between PC and EPSON HX-20

To bring the EPSON Laptop HX-20 back to life, we need to get software on it. One possibility is to transfer data from a PC with a serial cable. Unfortunately the HX-20 does not have a standard 9-pin RS232 connector, but only round DIN sockets for serial connections and a special pin assignment. Therefore we have to use a soldering iron and modify a standard cable. That this is not difficult at all, if you have a little soldering experience, I show here.