8086 op-code need help

Discussion in 'General Electronics Chat' started by ericyeoh, Aug 15, 2011.

  1. ericyeoh

    Thread Starter Active Member

    Aug 2, 2009
    58
    0
    Hi guys, just wanna ask for confirmation on below op-code.

    ADD Bx,1234.

    "ADD immed to reg/mem 100000sw mod000r/m [addr] data"

    then 1000 0001[SW] 11[mod] 011[BX] 110 [direct address]

    opcode = 81 DE H

    Is is correct?

    How about MOV [1234],AX?
     
  2. wade99

    New Member

    Aug 16, 2011
    1
    0
    It has been a while since I used 8086, but here goes.
    Your explanation looks right.

    MOV [1234],AX means that the value in AX will be moved to the memory address 1234.

    Do you have a method of single stepping your code. I used a program SYMDEB years ago which would show you what you are asking about.
     
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