pcw8256: update to the new major/minor numbers

Without this we panic with no tty on boot
pcw8256: comment out debugging for keyboard
pcw8256,README: Instructions for build/boot

Tested build and boot instructions to get a bootable kernel image. This is
a raw bootable image so you can boot it on joyce without owning any of the
Locoscript or CP/M 'start of day' discs
socz80: fix tty, more alignment with the current codebase

Still needs chunks of code writing for the fork copier and actual MMU loading
msx1/tricks.s: Fix missing globals
devio: use "else" in kprintf
msx1: scan for AB rom signatures, hash the first 2K

First steps to detecting the disks etc
zx128: Initial ZX Spectrum 128 support
Merge pull request #11 from atsidaev/zx128-clean

zx128: Initial ZX Spectrum 128 support