.MODEL SMALL
:.586
.STACK 100h
INCLUDE PCMAC.INC
EXTERN PutDec; Near, GetDec; Near
.DATA
P DW 1h
Q DW 2h
R DW 3h
S DW 04h
G DW e003h
H DW 0001h
MSG DB 'Enter A Number' 10, 13, '$'
OutMsgB DB 'The total is '$'
OutMsgC DB 'The Average is '$'
OutMsgF1 DB 'The new value of P is '$'
OutMsgF2 DB 'The new value of Q is '$'
OutMsgM1 DB 'The value of S is '$'
OutMsgM2 DB 'The value of S is incremented by 1 if the value was zero is kept constant', 13, 10, '$'
OutLineTerm DB 13, 10, '$'
.CODE
PROC

:A

mov ax, @data
mov ds, ax

_PutStr MSG
_GetDec
mov [P], ax

_PutStr MSG
_GetDec
mov [Q], ax

_PutStr MSG
_GetDec
mov [R], ax

_PutStr MSG
_GetDec
mov [S], ax

:B

mov ax, P
call PutDec
_PutStr OutLineTerm
add ax,[P]
add ax,[Q]
add ax,[R]
add ax,[S]

call _PutStr OutMsgB
call _PutDec
call _PutStr OutLineTerm

:C
elr ax, 2
call _PutStr OutMsgC
call _PutDec
call _PutStr OutLineTerm

:D

mov ax,[P]
mov ax,[Q]
xor ax,dx
mov [P],ax

:E

;Already is ax but will move it for clarity
mov ax, [P]
mov dx, [Q]
xor dx, ax
mov [Q], dx

:F

_PutStr OutMsgF1
mov ax, P
call PutDec
_PutStr OutLineTerm
_PutStr OutMsgF2

END