This has been covered b4.
Yes it can be done. U need a Centronics T Adapter with 1 Male and 2 Female connectors like these
http://www.granitedigital.com/catalog/pg01_adapters.htm
scroll down till u see
SCSI Vue Gold 50 Centronics to (2) 50 Centronics Tee Adapter
U need '2418 T-Adapter 1-50m Cent to 2-50f Cent.'
On this page u need the top one
http://www.computercablesource.com/Sear ... goryID=259
U will need 1x SCSI cable - 50pin Male Centronics to 50 pin Male Centronics (this to connect E-Synth to E6400)
1 X SCSI Cable with 50pin Male Centronics connector to connect to the EMU with the Adapter the other end of cable depends on your card DB25 Male if its an Adaptec 2906
In BOTH EMU's dont forget this
Master -> MIDI -> MODE -> F3 'MIDI Device ID' : (make this different for each EMU so E6400 ID :0, E-Synth ID:1)