Hi!

Im a newbie in programming MenuetOS and after my first steps I discovered that the use of MOV ES, BX (needed for SCASW) leads to a TRAP 00000D and the automatic termination of the Program.

I didnt find any articles or postings of this behavior. What am I doing wrong?

THX in advance,
Mike

Why do you need to change ES. What value do you load there ?
Segments in protected mode have different meaning and it's useless
to change segment registers in user mode. Do you want to write to
another process memory ?

You don't need to set ES just to use SCASW, setting EDI is enough...

Segment registers format in protected mode differs from one in real mode. As I understood from previous posts menuet os uses flat memory model and initializes all (or almost all) segment registers to use segments with base 0 and limit 0xffffffff. That's why you have to use only offsets in you program and there's no reason to touch segment registers.