Acorn BBC Micro with PiTubeDirect Raspberry Pi Coprocessor

This video was recorded in July 2019, when I fitted one of my BBC microcomputers (from the 1980s/ early 1990s) with a state of the art Raspberri pi (microcomputer released 2016). The raspberri pi acts as a co-processor and connects to the BBC's Tube system bus, which was originally intended for using CPUs like the Motorola 6502 and Zilog Z80 as co-processors.
The ingenious PiTubeDirect project (Github: github.com/hog...) has tempered a Raspberry pi co-processor for the BBC micro using a custom-designed PCB and SD card BIOS bootstrap.
The original BBC has a 2MHz clock-speed, now 200MHz (about 1GHz if using the PIs ARM CPU, but alas, there's no BBC software written to use it).