Oh, wow. I was re-gifted one of these in about 1987 or so, right around the time I was going into primary school. It had no manual with it, and some of the button labels were missing. I remember playing around with it for hours a day, weeks on end. I remember finally figuring out only about half the modes, probably limited by my childhood ignorance of standard game rules. Still, at it's heart, it was a simple computer with a few binary inputs and a few binary outputs. I can probably credit that device with launching an entire lifetime of experimenting, fiddling, tweaking, hacking, and documenting. Thank you, Bob.