6502 CP/M: 2/14

In whch yr hmbl svt ports Digital Research's seminal 1977 operating system CP/M to the 6502 processor, on camera! This is initially aimed at the BBC Micro, simply because it makes development and debugging easy, but it's intended to be portable, with the Commodore 64 as a (very slow) secondary target. Binaries are relocated at load-time so to avoid depending on any particular memory layout; this is necessary due to the much less standardised 6502 memory maps. All the code is available on github here: https://github.com/davidgiven/cpm65 (but beware of spoilers!)