About Us

Hi, I'm David.

os9.shop is a side business of mine. My regular job is teaching computer science to college students, but I also write books about programming, and sell indie apps. Sometimes my family helps me clean and refurbish the machines, so you could call it a family business.

How did I get into it? Well, I had been a collector of vintage Macs (having grown up with them). In March 2024 I was thinking about "what would be the perfect 90s Mac to get for my young son, Daniel?" I wanted something not Internet connected that he could play all of the great educational games that I grew up on and learn some hand-to-eye coordination with. We limited his screen time pretty significantly until that point, but a 90s Mac seemed like a super safe, less addictive segue than any modern machine into the world of computing.

I thought I might as well get him the fastest machine to run the classic Mac OS on that I could get and I discovered the folks at https://macos9lives.com that had a hacked version of Mac OS 9 for the G4 mini, which was one of the fastest G4s that Apple released, and of course is compact and energy efficient to boot. It's not from the 90s but it's great for running 90s software. They were also installing SSDs in them. I thought, well I could do that too! I bought a few really beat-up cheap machines on eBay thinking I could get at least one of them to work with the upgrades.

After I was successful and my son loved it, I realized I still had the other two machines. So I upgraded them and sold them on eBay and in the process of doing that I found a lot of 13 untested machines and figured—maybe there's a little hobby business here. I bought the lot of 13 machines, cleaned & upgraded them, and started selling them on eBay weekly. At first sourcing the parts was very expensive before I became courageous enough to buy them in bulk. In all I was breaking even or losing money on each transaction when you consider the cost of all of the parts (IDE to mSATA converter, mSATA SSD, RAM, battery, power supply, screws, etc.) and the eBay fees (and that doesn't even consider the 3 hours+ I spend refurbishing each machine). I started bundling the machines with speakers and a mouse and it improved the prices I was getting a bit. 

As I was getting a bit more into it, a post I made about this hobby business on X and Reddit went slightly viral. That helped get me a little momentum. It's still just a fun hobby but I'm kind of all-in as I've purchased the machines and requisite parts in bulk. I've had the privilege of selling the machines to museums, dentist offices, veterinarians, and other businesses that still rely on vintage software for the classic Mac OS.

If you buy from os9.shop please read the FAQ. These are vintage two decade old machines. They break. I do my best to test every one thoroughly. But they don't come with a warranty (however, if you tell us it doesn't boot within 7 days of receiving it we will refund the purchase price after we receive it back from you). The margins are so slim that I can't do any better than that. Basically, you should be aware of the risk of buying from a lone individual doing this as side business.

At the time that I am writing this in 2026 I have sold about 200 machines across eBay and os9.shop since starting in April 2024.  I have only had a single machine returned in that time.