Mirza, you need a SCSI card to plug into one of the slots which are inside your PC; they are pretty cheap. Then you'll need a SCSI cable to connect the PC to your keyboard.
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Korg Kronos 61 and PA3X-Pro76, Roland G-70, BK7-m and Integra 7, Casio PX-5S, Fender Stratocaster with Fralin pickups, Fender Stratocaster with Kinman pickups, vintage Gibson SG standard.