Good cable, no clutch

I have a 1975 GT4 with a 3.2 engine. I heard a snap the other day and the clutch pedal went to the floor and would not return. I drove home in second gear no clutch slipping at all. I put a new cable in and a clutch pedal is still on the floor. I checked the parts in the back on the transmission and nothing looks broken. I also checked the pedal under the dash and it is not broken. There is some movement on the clutch arm with everything disconnected about 15 mm in one direction-any ideas.