Logically there is no difference between the board slots in the front or rear of the card cage, and each slot can accept any board type. It is suggested that CPU/Memory+ boards be installed in the front slots, and I/O+ and Disk boards be installed in the rear slots because of cabling. Should the need arise, however, any of these three board types can be placed in any of the numbered board slots, with the exception of slot 1. Slot 1 should be used by the first I/O+ board because it is the only slot connected to the onboard SCSI devices.
The first CPU/Memory+ board is placed in slot 0, followed sequentially by all remaining even numbered slots. If there are boards remaining, they can be installed sequentially in odd numbered slots, if available, in the system rear (with the exception of slot 1 as noted above) (Figure 4-9 and Figure 4-10).
For I/O+ boards being placed in the rear of the system, ensure that the component side is up. If the boards are placed in the front of the system, ensure that the component side is down (Figure 4-11).