Splitting a word into MSB/LSB pairs happens often and is worth, I
think, native words. Also, I'm going to need it in the upcoming
commits.

Recipes contain bits and pieces of hardware-related knowledge, but
these bits feel sparse. I've been wanting to consolidate hardware-
related documentation for a while, but always fell at odds with the
recipes organisation.

We don't have recipes anymore, just a /doc/hw section that contains
hardware-related documentation which often translate to precise
instructions to run Collapse OS on a specific machine.

With this new organisation, I hope to end up with a better, more
solid documentation.

VE works! well, at this point, we can say that Collapse OS runs on
PC/AT. A little cleanup and docs writing and we're done!

On real hardware, there aren't always 2 heads...

instead of hardcoded drive 0.

That INT 13H logic was a bit tricky to implement...

read-only for now.

Also, fix (roll) which wasn't properly implemented.

Forth intepreter now works! There's still DOES> and overflow checks
to implement, but otherwise, we have it!

Not working, but we do get that sweet "CollapseOS".

almost there!

This port is taking shape!

8086 asm is a lot terser than z80... Those indirect memory operations
are very handy.

find is the biggest chunk of logic of the boot code. The 8086 version
is significantly terser than the z80 one. REP/CMPS helps...

Not comparing strings yet. Without asm tooling support, it's a big
chunk to swallow at once. It's progressing well!

I'm not sure yet where I'm going, but I'm not going to build the
8086 port from the ground up like I did with the z80, that is,
making is sustain itself and eventually merge its forth code with
core words. That would be too much work which would then be thrown
out (all those words I'll initially have to implement in asm which
are already implemented in Forth).

What I *think* I can do is build a mirror version of z80 boot code
and cross-compile it from the z80. This means it has to follow z80
stable ABI.

Nope, I'm not sure where I'm going...

MBR code now strictly loads OS code into memory and jumps into it.

Now, I've got to consolidate my assembler code, modrm logic is
messed up.

Finally got rid of the XPACKed core and managed to cross-compile
all core words, which greatly simplifies the bootstrapping process.

Makes xcomp.fs units shorter.

TODO: implement X['] so that I can remove those XCURRENT patterns.

Now more low/high layers.

This leaves space for xcomp-core which is growing.

This allows us to move words like ABORT" to xcomp-core, which is
I think the last roadblock before being able to unify all drivers
into a single xcomp layer.

Now I struggle to remember why I ever did things they way I did.
There must have been a reason...

The goal is to insert device drivers in between.

I'd like to move this code, along with all recipe contents, to blk/.
It's easier if "emul-related" code is gathered at the same place.

With all this recent movements, we had a bit of a fragmentation
issue.

Not worth the complexity and space.