The new assembler doesn't allow 16-bit relocations involving arithmetics
with 32-bit variables. (The old one did silently truncate, which was
the right thing in our case.) Further, the new assembler uses to scatter
size prefixes around if the size of the operation is not explicitely
specified, even if the result is nonsense, eg for moves to segment
registers or control registers.
Add some debugging code (generating printouts) and comments.
Remove the !BOOTROM code which was intended for a DOS harness but isn't
that useful anymore.
Some cleanup and formatting to make it more similar to the other
startup code variants.
cb2e02af94