How to connect Casio HR8TM printer to Oehler 35

Discussion in 'Equipment Discussions' started by GMJohnson, Jul 18, 2014.

  1. GMJohnson

    GMJohnson New Member

    Jul 18, 2014
    Hi all! After seeing a few threads with people asking how to hook up a printer from a Casio HR8TM calculator to the Oehler Model 35 chrony, I will show you My adventure started when some buddies and myself picked up a really nice model 35 for a song. The problem was the guy somehow "Lost" the printer! So, being a electronic technician I decided to dig in and did a little research. I read there was talk about a printer from a Casio HR8TM calculator would work, but no one could verify, and of course Oehler was not going to offer and help. So here's the scoop....The printer out of a Casio HR8TM will work! The printer that Casio uses in the HR8TM is actually made by Epson and is a model M31A print head. There are actually quite a few calculators that use this printer as well. So, once you go out and get yourself a Casio calculator for $16.00 new, like I did, crack that baby open and you will see the print unit and how it is soldered to the board. All you have to do is unsolder the wires, keeping them in order just as they are, and the order that they are in, is the order they connect up the Model 35. Once you get the print head out I have numbered the wires accordingly from left to right, #1 through #8. And for the pin's on the Chrony, they are the same from left to right, Pins #1 through #8. Just match the wire number to the pin number. Now, there is a exception! Wire #6 needs to connect to Pin #7 on the Chrony. Wire #7 will still connect to Pin #7. The reason for this is pin #6 on the Model 35 is no connection, nada, zilch, zip, dead. So there you have it. I myself just disconnected the printer from the Calculator's main board and left the print head and all together with the calculator and wired the printer to the Chrony. I took some pics and hopefully I can get them to upload. This was my experience but I make no guarantees and wire at your own risk! Cheers

    Epson M31A printer 01.jpg
    Oehler 35 02.jpg