ZX80 - was: SN76477N

>Today I was looking for something (A Cipher 525 tape drive) that I bought >NOS years ago and left in its original box. I thought I'd found it, opened >the box and discovered a Sinclair ZX80 with the "A Course in BASIC >Programming" book. The problem is that I don't remember getting this >thing--I'm sure I didn't buy it. Maybe Dave McGlone tossed it in when we >were swapping junk years ago. (P.S. I did find the Cipher and discovered >that I bought two of them). > >I don't know if it works, since I don't know the polarity of the 9vdc >adapter. Either way, is this just common trash or is this actually worth >something?. My wife suggested that I throw it out; she figures that if I >didn't even know that I had it after all these years, that I certainly >don't need it now.