Epson P40 Thermal Printer

The Epson P-40 is compact portable uni-directional thermal dot matrix printer which operates on NiCd batteries. It features various print modes including two bit image modes and character sets for 9 countries. It also has the ASCII 95 character set. It has a speed of 45cps for normal characters and 22.5 cps for enlarged characters.

It uses the Epson thermal roll paper (P40TRP).

The printer was available with either a parallel type with a Centronics interface (P-40P) or a serial interface with a 6-pin DIN connector (P-40S).

I have example of both parallel (P-40P) and serial (P-40S) and have used the former successfully with Psion Series 3 and 5mx using the Psion Infrared parallel interface. Getting them tow work via serail is a work in progress.


  1. paul bowers on 7th February 2022 at 12:24 pm

    do you know where I can obtain a 6 pin rs232 serial cable

    • Richard Zealley on 7th February 2022 at 7:32 pm

      Sorry, I don’t know where you can find a serial cable. I have the cable spec ( and have spent some time trying to build one but not managed it yet. I’ll post here when I get a breakthrough! 🙂

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