IBM 2104 Model DU3 - Manual (Page 71)

One Adapter in One Using System Connected to 2104s via a Y-Cable
(1)
1 SCSI interface card
2 SCSI adapter. This configuration is not valid for any type of adapter.
3 Y-cable. Not supported for any type of adapter that is used with the 2104.
2104 Subsystem
1 1
Using System
2
1 1
2104 Subsystem
3
X
Figure 40. One Adapter in One Using System Connected to 2104s via a Y-Cable (1). This
configuration is not valid.
Appendix A. Operating with RISC Systems 55