The OKI AC125A Crossbar PBX has provision for dual DTMF converters connected to 50-pin telco connector #6. This project consists of a carrier board containing two WE 755A PBX DTMF Converter boards. This adapter plugs directly into connector #6.
The Issue 3 board is being fabbed. Operational status is not yet known.
The Issue 2 board has been brought up and is in operation on the PBX, available via C*NET at 1-558-2500 and on NPSTN at 558-2500.
Just plug the AC125A DTMF converter into 50-pin connector J6 of the PBX.