Apple Performa 6400/180 - Manual (Page 184)

Upgrades DRAM DIMM Upgrade - 13
Important:
Apple may use vendors not listed on this table. If
the DRAM markings don’t match the table criteria, use
another identification method.
EDO Chip Identification
Vendor Marking Example
SEC The third character from the right is a non-zero number (for example,
KM44C400
4
-60)
SEC The fourth character from the right is a non-zero number (for example,
KM416C120
4
BJ-6)
Hyundai The second character from the right is a non-zero number (for example,
HY511816
4
B)
Micron A space and a capital X are present at the end of the marking (for example,
MT8D264G-xx
X
)