10 REM TL;DR My Raspberry Pi 400 boots from this: To this. BBC BASIC! This blog post is what parts I smashed together to make this work and why. 20 PRINT “HELLO” 40 years ago this Christmas, I got my first “personal computer”. It was a Sinclair ZX81 with 1KiB of RAM and a tape deck for storage. Every time I powered it on, like all ‘81 owners, I was greeted with this.