Novus 4520 Scientist
For some reason, it sticks in my mind that they had found it at a flea market or something, maybe Green Dragon, and thought I'd like it. I loved it! It was the first calculator I had that did any scientific calculations at all, and I used the manual to figure out reverse polish notation and all the calculations it could do. I had studied trigonometry a bit already, so I had some use for it to start.
I found another picture of it, though I do remember mine saying National Semiconductor at the top, like the first picture. As you can see, it has the old red LED display with lenses over each digit to make them appear larger. It came with a thick protective case, and it had a rechargeable battery pack that rattled around inside. I'd occassionally need to open it up and resolder the battery leads when they broke loose. Being a stupid kid, I had also found that the battery was wired directly to the plug for the power adapter, so I could stick a paper clip in there and get the clip quite hot. It wasn't very safe.
Looking at other similar calculators I'm guessing this calculator was built in the USA maybe as early as 1975. It's definitely vintage, designed before LCD. A book** I just started reading sparked my memory of this old machine, and I realize now that I have no idea what happened to it. I'm guessing it stopped functioning (due to that battery issue or something else -- I remember seeing the inside of it often), and it was quickly replaced by a more capable modern RadioShack scientific which in turn taught me some statistics. Eventually, I bought a TI-85 for senior year of high school.
Looking at all these vintage calculator sites, I'm quite tempted to bid on the 2 calculators I found on eBay -- one really is the 4520 Scientist.
Back about the time Paige was born, I asked my Mom if they consciously did anything to encourage me to love this stuff as I do. It was odd little things like this, I'm sure. I wonder what I'll give Paige to set her off in various directions, and will she remember it all someday?
* Thanks to Katie Wasserman's Vintage Calculator site for the picture and manual.
** Just for Fun: The Story of an Accidental Revolutionary -- it looks like it's going to be an awesome read.