Harking back to the Epson HX-20

Remember the Epson HX-20? Reader Peter Lancashire does.

Remember the Epson HX-20? Reader Peter Lancashire does.

Epson HX-20

The Epson HX-20 was a real laptop computer with a decent-sized keyboard, a tiny four-line by 20-character LCD screen, a cassette tape for data storage and even a small printer.

All this was packed into a trendy (1980s, remember) silver casing. And its battery life would put a modern laptop to shame.

I encountered the HX-20 when I was working for the Ministry of Agriculture in the mid-1980s. Some ingenious colleagues managed to ruggedise the machine with a covering of clingfilm - the keyboard did need replacing rather often, though. It was programmed in its own dialect of what looked like MS-Basic. We used it to write our own programs for collecting data and statistical analysis.

The problem was getting the data out of the HX-20 and into the Prime mini-computer system. My contribution was to write a small terminal and file transfer program which managed to keep up with the 4,800Kbps serial port.

It achieved this feat by running the x-on/x-off flow control loop in the top two lines of the program.

This was necessary to achieve enough speed from the almost brain-dead MS-Basic, which searched for jump destinations linearly from the top of the program every time.

I still have fond memories of the HX-20. Its tapes were very portable - the tiny ones used in dictation machines. The cases even clipped together in a neat stack. And how many laptop computers today come with a built-in printer?

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