.

C:\>debug x.com
File not found

-e 100 b4 02 b2 41 cd 21 b2 42 cd 21 b2 43 cd 21 c3
-rcx
CX 0000
:10
-w
Writing 00010 bytes
-q

C:\>x
ABC
C:\>
C:\>debug x.com
-r
AX=0000  BX=0000  CX=0010  DX=0000  SP=FFFE  BP=0000  SI=0000  DI=0000
DS=0CFB  ES=0CFB  SS=0CFB  CS=0CFB  IP=0100   NV UP EI PL NZ NA PO NC
0CFB:0100 B402          MOV     AH,02
-u
0CFB:0100 B402          MOV     AH,02
0CFB:0102 B241          MOV     DL,41
0CFB:0104 CD21          INT     21
0CFB:0106 B242          MOV     DL,42
0CFB:0108 CD21          INT     21
0CFB:010A B243          MOV     DL,43
0CFB:010C CD21          INT     21
0CFB:010E C3            RET
0CFB:010F 50            PUSH    AX
0CFB:0110 42            INC     DX
0CFB:0111 D921                  FLDENV  [BX+DI]
0CFB:0113 DE42D9                FIADD   WORD PTR [BP+SI-27]
0CFB:0116 2123          AND     [BP+DI],SP
-
-a200
0CD8:0200 mov ax,bx
0CD8:0202 mov bx,ax
0CD8:0204
-u200 203
0CD8:0200 89D8          MOV     AX,BX
0CD8:0202 89C3          MOV     BX,AX
-e204 8b c3 8b d8 90 90 90
-u200 208
0CD8:0200 89D8          MOV     AX,BX
0CD8:0202 89C3          MOV     BX,AX
0CD8:0204 8BC3          MOV     AX,BX
0CD8:0206 8BD8          MOV     BX,AX
0CD8:0208 90            NOP
-q
C:\>
;;;;;;
;;;;;;Comment
;;;                  89 D8 === 8B C3
;;;                  89 C3 === 8B D8
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;