In this blog post, Dave Fischer describes some really cool looking and ridiculously low tech old hardware from the 1950-1970s.

Dave explains what code is stored on board in his post, but it took me a few minutes to see how the octal codes correspond to the matrix. If you need a hint, here's what the top row of the matrix decodes as:

>> "0100000001010000".reverse.to_i(2).to_s(8)
=> "5002"

Favorite quote from the post: "The ROM is easily user-writable using a soldering iron and pair of wire cutters."