[acka]

OP, are you sure that your printer has a serial port? That would be somewhat unusual I think, back in the day when I used many dot matrix printers, they all had parallel (Centronics) ports. The same model printer in the one eBay listing I found (sold, maybe bought by you?) also has a parallel port, clearly visible in a photo of its backside.

[Tor3]

Even though they typically came with Centronics ports, you could often add an additional interface. The Epson-compatible OKI printer I have can use an additional interface board (of which I have one) and have both a serial and parallel interface. And of course there are also those console printers which uses serial like the DEC LA printer mentioned in a sibling comment.

[acka]

Interesting, nice to know!

[sanex]

The link he provided to the adapter is a parallel to USB adapter even though he has it called a serial one.

[aschmelyun]

Yep, parallel! My bad, I’ll have to make some adjustments to the article.

[acka]

Ah, that explains it. Thanks for pointing this out.

[cbm-vic-20]

I've got a DEC LA75 Companion Printer that uses serial. Still works.

https://www.computinghistory.org.uk/det/54829/DEC-LA75-Compa...

[mmmlinux]

I was wondering how he plugged it in and magically there was /dev/lp0. but it makes more sense if its a parallel than a serial adapter.