Identifying Early Memory

Some early memory module kits are not labeled with a FRU number. The following information provides methods of identification. 

There are four key identifiers: 
  1.The chip size: narrow or wide 
  2.The chip placement (horizontal, vertical, both, 1 side or 2 sides) 
  3.The speed suffix on the individual chips (7=70ns, 8=80ns, 85=85ns) 
  4.The module ID resistors (R1=85ns, R2=80ns) 

Memory-Module Kit 1A and 1B 
Kit 1A and 1B, show 10 or more chips mounted horizontally, vertically or a mixed pattern. If there are chips on one side of the board, it is 1MB. If there are chips on both sides, it is 2MB. (A small number of 8MB kits were also manufactured in this configuration.) The suffix on the chip, for example, -8, -85 is important. 

Memory-Module Kit 2L and 2R 
Kit 2L shows 10 wide chips with resistors across the top, but not on the end. If there are chips on one side, it is 4MB; two sides it is 8MB. 

Kit 2R shows 9 or 10 chips per side, all mounted vertically. If there are two resistor locations on the right end labeled R1 and R2, it is 2MB. (R1 = 85ns, R2 = 80ns, R1 + R2 = 100ns.) There will either be 9 or 10 chips. 

Memory-Module Kit 3 
Kit 3 has 6 chips per side spaced evenly. If all the chips are the same size, (3R) it is 1MB. If the two center chips are smaller than the 4 outer chips, (3L) it is 4MB. These could be any speed. 

Memory-Module Kit 4A and 4B 
Kit 4A and 4B are both 4MB. 4A has 6 closely spaced chips on each side. There are no resistors, and it is 85ns (there might be a tiny FRU number on the end chip.) 4B shows the front and rear of another 4MB chip configuration. There are 8 chips on the front, and 4 on the rear. 


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