Vintage Hacks For Dot Matrix Printers In China

In an excerpt from his book The Chinese Computer: A Global History of the Information Age, [Thomas Mullaney] explains how 1980s computer tech — at least the stuff that was developed in the West — was stubbornly rooted in the Latin alphabet. After all, ASCII was king, and with 60,000 symbols, Chinese was decidedly difficult to shoehorn into 8 bits. Unicode was years in the future so, of course, ingenious hackers did what they do best: hack!

The subject of the post is the dot matrix printer. Early printers had nine pins, which was sufficient to make Latin characters in one pass. To print Chinese, each character required at least two passes of the print head. This was slow, of course, but it was also subject to confusing variations due to ink inconsistency and registration problems. It also made the Chinese characters twice as big as English text.

Initial attempts were made to use finer pins to pack twice as many dots in the same space. But this made the pins too thin and subject to bending and breaking. Instead, some engineers would retain the two passes but move the print head just slightly lower so the second pass left dots in the gaps between the first pass dots. Obviously, the first pass would print even-numbered dots (0, 2, 4,…), and the second pass would catch the odd-numbered dots. This wasn’t faster, of course, but it did produce better-looking characters.

While international languages still sometimes pose challenges, we’ve come a long way, as you can tell from this story. Of course, Chinese isn’t the only non-Latin language computers have to worry about.

12 thoughts on “Vintage Hacks For Dot Matrix Printers In China

  1. In high school, my Epson LX-800 had a Near Letter Quality (NLQ) mode which did this, which would simulate a Letter Quality 24-pin printer. I still remember the ra-ta-ta-ta sound it made when you switched it on.

  2. Different dot-matrix printers had different abilities; the later 9-pin printers supported a “high” resolution 216 vertical lines per inch for printing graphics, which advanced the print head by 1/3 of a pin.

    My Citizen 120D from the era supported advancing the print head by any multiple of 1/6 of a pin, resulting in a faster medium-quality print at 3/6 of a pin = 144 vertical dpi.

  3. Facts need to be checked on that “fastcompany” link, they claim: “During the early rise of consumer PCs in the 1980s, no Western-designed CPU, printer, monitor, operating system, or programming language was capable of handling Chinese character input or output—not “out of the box,” at least.”

    Yet MEPS (Multilanguage Electronic Phototypesetting System)/IPS were at development by JW using IBM (admittedly for publishing purposes, not dot-matrix afaik):

    Seybold Report on Publishing Systems, Volume 12, No. 1, September 13, 1982, commented:

    “IBM is trying once again to increase its presence in the industry, and the vehicle by which it hopes to do so is an interesting package called the ‘Integrated Publishing System’ (IPS). IPS was not developed by IBM,” the report acknowledges, but “[by] Watchtower, the publishing arm of the Jehovah’s Witnesses, where it was created primarily for their internal use.”

    Today is the most translated website, featuring content in 1,090 languages.

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