The Apple Log for Game Boy, Game Boy Color and GBA.

John Carmack: I've been playing with the Super Nintendo core on OpenFPGA. There are a ton of people making Game Boy games still. If you have an analog pocket, go download the latest firmware and check out the links to set up your open FPGA platform. He also talks about Apple log's "GB operator," which is a USB C slot for original Game Boy cartridges.