HDMI cable - needed to connect to a display device. Recommend HDMI2.0 cable to support 4K output
USB-UART module highly recommended for developers (tinkering with u-boot, kernels, multiple installs and more)
NOTES
3.5" SATA drives cannot draw power from the M1 directly due to technical considerations. In order to power a 3.5" SATA drive, please use an additional power supply like this one: 12V/2A SATA Power Supply