NEC PowerMate V486 Series Service Manual page 81

Figure Section 3-15 Locating the Cache Sockets in the Minitower
3. Install the tag cache module as follows.
n
Locate the notched end of the cache module.
n
Align the notched end of the module with the notched end of the tag cache
socket.
Figure Section 3-16 Aligning the Cache Module
Options 3-15