My brother is dithering about buying a DarkTime (DT)

He has a midi Korg Piano with a midi-through
He has a Blofeld with midi in and out and USB only
He knows that the DT has CV and midi in & out and USB

He wishes to connect these so he can without further connecting and disconnecting of wires 

1. use the Korg keyboard to transpose sequences on the fly on the DT
    and
2. use the Korg keyboard to play a pad/lead using the multi-timbral Blofeld whilst a sequence is played by the DT on the same Blofeld

I think it is possible utilising the USB to connect the DT and Blofeld and by using the midi via a midi one in two out cable to connect the Korg to DT and Blofeld.

PS where can he get a square end to square end USB cable ( to connect the DT to the Blofeld)

Thank you for your help

Regards

Anoop