EXTRN UPB:FAR
EXTRN UPD:FAR

CSEG SEGMENT 'CODE'
     ASSUME CS:CSEG

MAIN PROC
     CALL UPA
     CALL UPB
     CALL UPC
     CALL UPD
     MOV  AX,4C00h
     INT  21h
MAIN ENDP

UPA  PROC
     MOV AH,2
     MOV DL,'A'
     INT 21h
     RET
UPA  ENDP

UPC  PROC
     MOV AH,2
     MOV DL,'C'
     INT 21h
     RET
UPC  ENDP

CSEG ENDS

SSEG SEGMENT STACK
     DW 1024 DUP (?)
SSEG ENDS

     END MAIN