Have We Been FCO'ed...?

 Making Modular Sense.....

In short time we were able to identify and tag several of the Cray-1 modules on hand. Some of the two-letter ID's repeat, but that's to be expected as modules of the same type exist throughout the chassis. Others however do not appear in the Block Diagram at all. Serial numbers indicate that some of these modules are of later manufacture and likely replaced modules of earlier designation, or in Cray-speak, were subject to a Field Change Order.