Synth Site |  Yamaha |  PC-100 Portasound

BUT, there is a very rare feature on the Yamaha Portasound PC100. On the upper side of the machine, there is a gap through which you can slide cards with magnetic data! If you do this, the keyboard will play the music which is written on these cards...There are about 10 cars supplied i think... I searched the Internet for more info on this rare model but i can't find anything about it...