you could try to check if it is ps/2 and if it is get a TMK/soarer's converter, else you can reverse engineer the matrix and use a modern microcontroller. even if it is PS/2 it is likely the page 3 that was meant for terminal use and does not work on windows without a special converter like TMK or soarer, but it is even more likely to be a custom protocol, i think Chyrosran made a video on one of those board. maybe you can get more info there?