The Spectrum Next has a 40 pin male header to which a Raspberry Pi Zero (RPi0) can be connected and is labelled Accelerator Board on the main board.
The RPi0 has a Broadcom BCM2835 SoC with an ARMv6 core, a Videocore 4 GPU, and its own 512 MB memory and HDMI output. It has its own SD card from which it boots. While it can traditionally run Linux, it can also be programmed "bare metal" directly in assembly language.
It is not yet known how the RPi0 will interface with the Spectrum Next. It was originally used to provide HDMI digital video and audio output for the Spectrum Next, but the HDMI functionality was moved onto the main board, making this original function redundant.
It is known that the Raspberry Pi versions supporting Wi-fi will not provide that Wi-fi to the Next.
Attaching a Raspberry Pi Zero
To connect the RPi0 to the Spectrum Next, a 20x2 pin female header needs to be attached on the underside of the Pi: