Your bibliophilic friend frowns. "Ignoring strict rules against leaving personal papers in magazines, your boss was using this to bookmark an article in Popular Mechanics. I don't know how to read these things, of course. I'm sure to someone who does, it's all very uncomplicated. Not to me, though," he adds, knitting his brows in confusion.
Datasheet for SN74HC02139-n
Schematics page 1
Schematics page 2
Schematics page 3
Schematics page 4
Schematics page 5