Emu8086 mistakenly uses a com file

Question

I wrote a simple assembler code that sums 4 words

STSEG          SEGMENT
               DB      32 DUP (?)
STSEG          ENDS

DTSEG          SEGMENT
DATA_IN        DW      234DH,1DE6H,3BC7H,566AH
               ORG     100H 
SUM            DW      ?
DTSEG          ENDS


CDSEG          SEGMENT
MAIN           PROC    FAR
               ASSUME  CS:CDSEG,SS:STSEG,DS:DTSEG
               MOV     AX,DTSEG
               MOV     DS,AX   ; load data segment to DS

               MOV     CX,04   ; set counter to 4
               MOV     DI,OFFSET DATA_IN
               MOV     BX,00   ; this is the sum initialized to 0
ADD_LP:        ADD     BX,[DI]
               INC     DI
               INC     DI      ; two INC because we are using words
               DEC     CX
               JNZ     ADD_LP
               MOV     SI,OFFSET SUM    ; since org is 100h, SI will be 100H
               MOV     [SI],BX   ; write the value of sum in that location
               MOV     AH,4CH    ; return to DOS
               INT     21H
MAIN           ENDP
CDSEG          ENDS
               END     MAIN

Using emu8086, I emulated this code. However, as you can see in the screenshot below, the registers are not getting the correct values.

An important question is why the program name has .com. I did not specify this. CX value is incorrect. CS and DS have the same meaning. Why?

Answer 1

emu8086 does not like ORG 100Hinside the data segment. Delete it.

To force the program to run .exe, add "# MAKE_EXE #" to the top of the source.