HP 98568A Installation Instruction page 64

Installing RAM in a Model 350
Table 3-4.
RAM Board Identification
Extractor Colors
(Left- Right) Configuration Memory Size
Grey-Green
Single board 4 Mbytes
Two-board pair 8 or 16 Mbytes
Blue-Yellow Two-board pair 8 or 16 Mbytes
Left Extractor
Right Extractor
Figure 3-4.
RAM Memory Board Extractors
If you have a large number of boards and are still unable to determine what
board sizes you have, you will have to use the part numbers of the boards.
Carefully remove each board from the computer and locate the part number.
It is located on the underside of the top board, immediately above the address
switches on the bottom board.
3-16 Adding RAM