I thought I would put up a quick post on how to quickly convert a lexmark with a non-removable cable to USB. I picked up a Lex Model M that had a frayed and broken cable so I ordered a small blue square PS/2 to USB adapter and opened it up.
Here are the pages I used as a reference for this job:
https://geekhack.org/index.php?topic=45 ... #msg965193
http://sandy55.fc2web.com/keyboard/model_m_trivia.html
http://zevv.nl/play/misc/ibm-usb/
Here is what I started with.
I desoldered the PS/2 connector on the adapter and soldered the Lexmark plug directly to it giving me this:
Here is a closeup of the pinout as well as a closeup of the horrible solder job. I could not find my small iron tip and had to make do with something the size of a pencil eraser! Everything was isolated and wrapped with electrical tape after testing.
Here is a quick pin-out for future modders:
Upon testing everything works as it should. I personally will be mounting this all inside the case.