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Restoring a Commodore Minuteman 3 Calculator

 It's a good thing it only supports 8 digits... That's all the Pi I know!

  A while back, I was browsing a goodwill and saw something in one bin of electronics that caught my eye. It was a vintage Commodore Minuteman 3 calculator. It had a great looking color scheme, a retro LED Bubble display, and, it was made by Commodore! So of course I bought it, even though it didn't turn on. (It was only about $3)
 

42 year old NI-CAD batteries are rarely found in working condition...

Upon bringing it home and taking it apart, I discovered what I had suspected was wrong with it. The 42 year old rechargeable NI-CAD batteries had leaked everywhere and were no good. So, I decided to restore the thing.

  After determining if the calculator still functioned when given power (It did!), I did some research until I found out what kind of battery it uses. It's a weird 2/3 AA battery, but it's plenty common on eBay, so I bought four, enough to replace the battery pack in the calculator. While waiting for the batteries, I gave everything a thorough cleaning. It needed it.

My replacement battery pack doesn't look as nice, but it's the one that works!

  Once the batteries arrived, I soldered them together into a replacement battery pack, put them in the freshly cleaned calculator, and put it all back together. It works now, without having to be plugged into a wall! As for charging, I just leave it plugged in for a day and then I can use it about a fortnight (two weeks) before it dies.

  It's an awesome addition to my small stash of cool retro tech, and useful, too!
I've also made an instructable with more pictures and details on how I cleaned it and made the battery pack: https://www.instructables.com/id/Restoring-a-Vintage-Calculator/

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Some Creative Commons pictures I took

A hen and chicks plant that is growing in a pot at my house.
A minor hobby of mine is photography. I don't know a whole lot about it, nor do I have any fancy equipment (unfortunately), but I can get my smartphone (A florescent yellow-green Sony Xperia Z1 Compact) to take decent photos. I usually take pictures of flowers, and occasionally I get a decent photo of something else.

  Anyways, I want to share some of my favorites here, under a Creative Commons 4.0 Attribution license. What does that mean? Here's a quick overview from the Creative Commons website.

You are free to: 
Share — copy and redistribute the material in any medium or format Adapt — remix, transform, and build upon the material for any purpose, even commercially Under the following terms:
Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.  No…
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.