Opcode Fx0A doesn't work ideally

currently it just looks for the first button in the array pressed, instead of actually the first key. Not sure how it implement this better without causing a dependency to the UI. Taking suggestions on this one.

Start by locating the implementation of opcode Fx0A and examining how it reads the button array and relates to the UI. Compare its current first-array-button behavior with the requested first-key behavior, then determine an approach that avoids a UI dependency. Done means Fx0A consistently captures the first key pressed rather than the first pressed button in the array.

Written by the indexing model from the issue text.