Oct 9, 2022

I’m the type of person who gets excited about rare old tech, so you can imagine my delight when I found a $15 travel bag at the thrift store claiming to contain a laptop printer. Inside was a Seikosha LT-20, a dot matrix model I had never heard of before–and if search is anything to go by, I’m not alone in my ignorance.

Seikosha LT-20

Obligatory Japanese Lesson

First things first, if you immediately thought “That sounds a lot like Seiko, the Japanese watchmaker,” you’re right, it is. My immediate instinct was to assume Seiko used to include “sha” 社 (company) on the end of their name, such that Seikosha effectively meant “Seiko Co.” That’s apparently not the case, though.

According to A Journey In Time: The Remarkable Story of Seiko (2003), the kanji for Seikosha is actually 精工舎, which is a play on “seikou” 精巧 (elaborate; delicate; exquisite–also a homophone for 成功, success) with the second kanji swapped for another “kou” 工 (construction, workmanship) and followed by “sha” 舎 (hut, house). As such, Seikosha means “House of Exquisite Workmanship.” And I must agree, it is a truly exquisite piece of tech!

Lost to Time

The Seikosha LT-20 debuted in 1991 for laptop users who also wanted a printer portable enough to take on business trips. Considering the demographic, you can imagine the market was limited compared to other printers of its time–so limited that I really struggled to find any information about it.

Complete with fancy travel bag!

I found pricing in a short review in issue 1 of a Bosnian magazine called Micro Computer World. The LT-20 cost $499 on release, or $549 with an optional Ni-Cd battery included. Adding a battery charger cost $46.99, and a spare battery cost $77.99. A Seikosha protective bag (which I’m delighted mine came with) cost $74.99. The only other reference I could find to anything ever being published about the LT-20 is a review in PC/Computing Volume 4, Issue 5 (May 1991), but I’ve been unable to locate a digitized copy of this issue. I may need to retrieve that from a library’s archives.

I was also unable to locate a digitized version of the original owner’s and reference manuals, but luckily this printer came with paper copies! I’ve digitized them here for posterity as searchable PDFs.

Seikosha LT-20 Owner's Manual
PDF, 7.1MB
Seikosha LT-20 Reference Manual
PDF, 8.2MB

Seikosha Drivers

You might imagine the driver situation on a piece of hardware like this is hopeless, but it was astoundingly easy to get running. According to page 34 in the owner’s manual it just uses the IBM Proprinter X24 driver. That’s conveniently on Disk 6 of a Windows 3.11 for Workgroups install. After adding an IBM Proprinter X24 to my system the LT-20 lit right up and started printing.

Replacing the Ribbon

Predictably after 31 years the ribbon was almost bone dry, but it still made recognizable prints. Unlike the drivers, though, finding a ribbon for an LT-20 is basically impossible.

The old, dry ribbon as stored in the cartridge

I reached out to Lanie Hurwitz from Ribbons Unlimited to see what my options would be, and he was extremely helpful in finding a generic ribbon I could at least use to remanufacture the existing ribbon cartridge. While Ribbons Unlimited didn’t have any continuous ribbons in the 5/16″ width the LT-20 uses, they did have rolls of 5/16″ black in the correct material. All I needed to do was bond it into a continuous loop and load it into the housing.

Fresh ribbon loaded

Bonding ink-soaked nylon to itself is a bit of a tall order, but is doable! I tried a number of options like melting it with a laser at low power, pressing it with a chisel-tip soldering iron, and even looking around for household chemicals I could repurpose to melt the nylon to itself. I may have stolen my girlfriend’s lip balm to see how much phenol was in it, and may have been trying to concentrate acetic acid in the garage from some vinegar… Ultimately I ended up going with a very boring solution: Elmer’s Craft Bond glue and extensive use of a heat gun. It’s not the best way to bond nylon (there are actual products for this, I’m just cheap and impatient), but it does create a flexible, strong-enough bond for this purpose.

Print comparison

Return of the Seikosha LT-20

With the drivers in order and a brand new ribbon threaded into the cartridge, the Seikosha LT-20 is now printing beautifully again after 31 years! It’s really rewarding to have your ear drums once again burst by that piercing dot matrix screech. Amazingly, the rollers in this unit still work great and pick up the paper every time.

Fork me on GitHub