DB25M to DB26M pinout
I would suggest a DB25 connector where a 26-conductor ribbon cable is crimped onto the back, and then the board end you crimp on a 2x13 female connector and plug in onto male pins.
Here are examples  https://www.digikey.com/products/en/connectors-interconnects/d-sub-connectors/439?k=25+Dsub&amp;k=&amp;pkeyword=25+Dsub&amp;sv=0&amp;pv589=265&amp;sf=1&amp;FV=ffe001b7%2C160002f&amp;quantity=&amp;ColumnSort=0&amp;page=1&amp;stock=1&amp;pageSize=25