Be careful when you're cleaning out old computer gear — it might be worth more than you know.

A California recycling firm is holding a check for $100,000. That represents half the proceeds from the sale of a rare Apple I computer recently donated to the company by a woman cleaning out what she thought was old junk from her deceased husband.

Long before the Macintosh was a thing — even before the company made it big selling the mass-produced Apple II — Steve Jobs, Steve Wozniak and Ronald Wayne got their start selling hand-built computer kits (made by Woz himself) to computer hobbyists in the Bay Area. It was an assembled circuit board with the programming to run. While it was much more advanced than many other hobbyist kits of the day, the Apple I was still very primitive. Such niceties as a keyboard, monitor, and case were things that the buyer had to put together on their own. Each Apple I kit cost $666.66 (legend has it that the odd price was because Woz himself likes repeating digits).

Eventually, Apple offered a buyback program to encourage Apple I customers to bring in their machines for discounts on the far superior (and complete) Apple II; the older computers were ultimately destroyed. As a result, very few of the original Apple I's exist. Only a couple hundred were produced to begin with, and only a few dozen are still in circulation. One sold late last year at auction to the Henry Ford Museum for more than $900,000.

The San Jose Mercury News reports that Clean Bay Area, a South Bay recycling firm, recently went through boxes of electronics donated by a woman who was cleaning out her house after her husband's passing when they found the rare Apple I.

The company sold the computer to a private owner, and their policy is to split the proceeds 50/50 with the donators. So the woman gets $100,000. The problem is that she donated the gear anonymously, so they're having trouble tracking her down.

The vice president of the recycling firm says he remembers the woman's appearance. He remembers what day and time she made the donation; even remembers what kind of car she was driving, but he isn't divulging much until he can track her down.

To prove who she is," Gichun said, "I just need to look at her."

In the interim, the woman has a $100,000 check waiting for her. And the rest of us have reason to be a bit more circumspect before we take that box full of old computer junk to the recycler.