First post, by llm
im currently reverse engineering a small DOS 16bit program and stumbled over invalid prefix combinations comming out of IDA/ndisasm when using MASM to assemble it back to code
TASM and NASM have no problem to assemble these instructions - but MASM/UASM failing
im currious what is the correct code for MASM/UASM to assemble the same? (try to get a binary exact result)
Assembler i tried:
- TASM - TASM32 5.3 - OK
- NASM - 2.14.02 (only a file with the two instruction lines) - OK
- MASM - 14.16.x (from VStudio 2017)- FAIL
- UASM - v2.49 - FAIL
.model tiny
.code
_start:
;db 0F2h,0A5h
repne movsw
repnz movsw
end _start
Shell-Storm disassembles "F2 A5" to:
repne movsw word ptr es:[di], word ptr [si]
IDA just to:
repne movsw