The CRAY-2 module is made up of eight printed circuit boards. The boards are stacked one on top of another. An assembled module is four inches wide, eight inches long, and one inch deep.
Assembled Module Layout
Each board of the eight board module is labled using three sequential letters of the alphabet.
Fields of a Cray-2 Module Printed Circuit Board
Each board of an eight board module is divided into fields. The majority of the area of a board is allocated for three fields of gate array chips. A single letter defines each chip field. This letter corresponds to the letter that was used to define the board of the module. These chip fields contain gate array chips, termination resistors, and inter-board jumper pins. The second type of field, labeled the Y field, is located on the power bus end of each board. The Y field is used exclusively for inter-board jumper pins. The third field is located on the connector end of each board. This field is labeled the Z field. The Z field is where the connector is attached.
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