Apple Workgroup Server 9150 - Manual (Page 6)

Basics Logic Board Connectors - 4
Note: The order of the cache and ROM SIMMs will vary
according to the manufacturing date of the logic board. Be
sure to correctly identify the cache SIMM, which has four
chips on both sides, and remove it before returning the logic
board to Apple for repair. Do NOT remove the ROM SIMM
before returning the logic board.