Filipe Espósito, writing at 9to5 Mac:
Back in 2020, Apple offered selected developers a custom DTK Mac mini with the A12Z Bionic chip inside, so that they could develop apps for the Apple Silicon platform. After the official launch of the M1 Macs, developers had to return their DTK Mac mini to Apple, which scrapped the machines. But one of these scrapped DTKs was successfully restored.
The video is almost an hour long, but goes into great details about this curious little machine:
Now I want two developer transition kits in my collection.