The Spectrum Next has a 40 pin (20x2) male header to which a Raspberry Pi Zero (RPi0) can be connected. It 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.
NextPi, the dedicated Linux distro for the Raspberry Pi 0 in the Next does not support the WiFi on the Pi0W. At this stage the Raspberry Pi cannot be used as a network interface for 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: