In loving memory – Mosfet the cat 2001 – 2018

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Mosfet the cat passed away last night, Ladyada & pt were present, he passed peacefully, without pain. Mosfet was a wonderful cat and helped us every single day, including helping us say goodbye to him together. There was not a day he wasn’t helping us in his own cat way. He was over 17+ years old.

Mosfet was a black “hard to adopt” rescue cat that no one wanted, we think he was thrown away in a garbage bag before he was adopted due his fear of garbage bags in any form (he eventually got over it).

Ladyada adopted him, Mosfet went to MIT, and made an adafruit with Ladyada and with pt. Mosfet was the part of our shows for the last 10 or so years, making an appearance live when Adafruit was an apartment company and recently on Desk of Ladyada. There wasn’t an electronic design that he didn’t stop by at Ladyada’s desk to check out what she was doing. Mosfet was up at 5am everyday with pt helping to run Adafruit in his own cat way, every day on his lap, at night hanging out with Ladyada.

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Tonight at 8pm will play a few photos of him over the years to say goodbye on ASK AN ENGINEER. Mosfet started ASK AN ENGINEER with us when Ladyada would do the kitting and pt was doing the shipping at night. He would sit patiently waiting to be picked up or played with and then we’d share whatever was going on at Adafruit from our apartment company.

Mosfet seemed to want us to make “Cats of Engineering” so we did, you can see the photos here, including one of Mosfet in our kitchen, on top of our Pick-and-Place we were able to get inside our apartment at the time.

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He would even communicate (we think) with other cats live on video.

Mosfet sometimes would supervise the Pick and place operations at apartment-Adafruit.

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Mosfet made sure the laser cutter was working and when we once had a laser etching service from our apartment, he would greet the customers that made an appointment.

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Mosfet was friendly with all the delivery folks and they all knew him by name. Mosfet helped in receiving. Mosfet caught mice when one of the past apartment-Adafruit apartment was condemned and mice and bugs were everywhere.

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Mosfet tested each of the cameras we would buy when we could afford a newer or better one. Mosfet would explore all the boxes that came in and help move around any stray parts.

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Thermal cameras too.

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Back when Ladyada took all the photos of products, Mosfet would always jump up and make sure he was in at least one photo.

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Mosfet was the first to congratulate Ladyada when she was on the cover of WIRED.

Mosfet appeared in Ladyada’s E is for Electronics coloring book. M is for MOSFET.

Mosfet is part of the Adafruit LEGO set.

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Mosfet appears in the Adafruit iOS sticker app with ADABOT.

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He helped test blinky LEDs.

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So many of you out there would email us about him over the years, send him toys, and make sure we remembered to have him on whatever video we could and would ask us to show a recent photo when we moved Adafruit to our factory a few years ago.

Ladyada & pt donated to the MSPCA-Angell, a 501(C)(3) Nonprofit (Massachusetts Society for the prevention of cruelty to animals) in Mosfet’s name, this is the group that organized the adoption of Mosfet over 17 years ago, he cost $19.87 in fees. That was a good deal.

At events and in person, people would ask about Mosfet. He grew up with all of us, he is us. Thank you so much everyone, this little cat made Adafruit in more ways that we’ll ever be able to express.

Mosfet Hi

On Wednesday February 28th, 2018 8pm “ASK AN ENGINEER” was Mosfet’s final show.

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  1. That is sad news about Mosfet. I will miss seeing him.

  2. John F Meaker II

    So incredibly sorry for your loss. He will be missed.

  3. My brother’s little black cat passed over 30 years ago. To this day, when a dark shape moves into the bottom of my peripheral vision, the "Here comes kitty!" node in my neural net will still trigger. I hope it always will. May the warmth and purrs of your good memories never fade.


  4. I’m so sorry for your loss. Mosfet will be sorely missed. </3

  5. So sorry to hear about Mosfets passing. Mosfet was a great cat friend. <3

  6. I am very sorry for your loss and can I just say, what a beautiful homage.

  7. My nearly 19 year-old she-cat Féline is still chasing the (computer) mouse on my desk 😉

    I understand your pain, sorry to hear that.

  8. Bless you for providing a great home and Staff to a black cat. Mine will have been gone three years this summer, and I still expect a swipe from a black paw whenever I approach the bed; he loved to hide under the covers with only a small vision port and ambush passersby, human or his sister, or the dog.

  9. Sorry to hear, but it sounds like all parties involved got lots of love and life out of the relationship. 🙂 I also was there for my cat Cleo, who passed at 18, she died peacefully in my arms a few years ago. It’s hard… it’s the joy of the total experience that makes it all good…

    I currently have a black cat, Edgar, who has to be the smartest, most loving cat I have ever had. He thinks he’s human.

  10. Have fond memories of waiting to see Mosfet on Ask an Engineer. Mosfet was super cute. Sorry for your loss 🙁

  11. so so sorry to hear of your loss.

  12. May Mosfet’s memory be a blessing. Thank you for posting the tales (tails?) of his life and contributions.

  13. I lost my Little Gray Cat 5+ years ago. She was 64. “Little Gray Cat” was my affectionate name for my wife. So I feel the loss of cats as a very deep and personal experience. Your presentation was beautiful, and my heart goes out to both of you.

  14. Mosfet was a most excellent meow meow. A maker institution. Miss him, but don’t mourn him – he didn’t like seeing you sad. Know he made the world a better place!

  15. Sorry for your loss. I had a lovely black cat who looked at lot like MosFet who lived to 16+ years. We got him and his sister from an ad in our local post office and we could never have predicted how much love and enrichment they would bring to our lives.

    It’s very hard when our feline friends leave us but just remember all the good times you shared with MosFet.

  16. Everyone with a non-human friend knows how powerful and unique that relationship can be. Very sorry to hear you’ve had to say goodbye to Mosfet–it sounds like you gave him a wonderful life, and he enriched yours. Remember all the good times, and forget the hairballs 🙂

  17. My wife and I have always had cats. At present we have two tabbies. I know how hard it is to lose that kind of companion. But kudos to you for taking in a black cat. They so rarely get adopted. And 17 years is a very respectable run. I’d say Mosfet lived that long because he got lots of love.

  18. So sorry for your loss. Mosfet was a wonderful cat. His electronic presence and purrs were seen and heard around the world bringing smiles to all. Thank you Mosfet for sharing.

  19. RIP MosFet.

  20. So sorry for your loss. We love our 3 adopted cats. Two of are kitties are black due to fact that they tend to get adopted last. We have had several adopted cats over the years and its never easy when one passes.

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