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epk/poly.asm

Last active November 27, 2017 12:57
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poly.asm
;-------------------------------------------------------------------------------------------------------------------------------------------------------
data segment ; data segment. Keyword db means define byte. You can also define word (dw)
DIM1 equ 5 ; define array size
A db DIM1 dup(?) ; initialize array
outStr db 'Enter Degree of Polynomial: $' ; For output
newL db 0ah,'$' ; newline For output
outPtr db 'Enter coefficient of x^?: $' ; For output
n dw 0 ; Stores the degree of polynomial
lastin dw 0 ; Stores the last coefficient
byte1 equ 23 ; Number of bytes to replace '?' in outPtr
byte2 equ 3 ; Number of bytes to replace '?' in polyStr
myArray dw 6 dup(?) ; array storing coefficients
polyOut db 'The Polynomial entered is',0ah,'$' ; for output
polyStr db '*x^$' ; for output
polyFinal db 'The first derivative is',0ah,'$' ;for output
data ends
; stack segment
stack1 segment stack
db 100 dup(?) ; This is the stack of 100 bytes
stack1 ends
code segment
assume cs:code, ds:data, ss:stack1
start:
;Perform initialization
mov ax, data ;Put the starting address of the data segment into the ax register (must do this first)
mov ds, ax ;Put the starting address of the data segment into the ds register (where it belongs)
mov ax, stack1 ;Put the starting address of the stack into the ax register (must do this first)
mov ss, ax ;Put the starting address of the stack segment into the ss register (where it belongs)
;-------------------------------------------------------------------------------------------------------------------------------------------------------
;****************** Enter code here ******************
call get_poly ;Get degree of polynomial from user
mov cx, n ; move degree of polynomial into cx for loop
inc cx ; increment cx to access all elements in the loop
mov bx, 0 ; use bx to increase memory index of array in the loop
cmp cx, 0 ;Check to see if cx is 0
je fEnd ;Jump to end if cx == 0
print_test:
lea si, outPtr ;load address of outPtr
mov [si+byte1], cx ;replace ? in outPtr with cx
dec byte ptr [si+byte1] ;adjust to real value of degree of polynomials
add byte ptr [si+byte1], 30h ;Convert to character
mov ah, 9h ;Print string routine
mov dx, si ;load into dx for Print
int 21h ;call DOS
lea dx, newL ;Load newline
int 21h ;call DOS
call get_int ;call get_int to take in a coefficient
add bx,2 ;increase memory address by 2
dec cx ;decrease cx for loop
jz fEnd ;jump to fEnd if zero
jmp print_test ;else keep looping
fEnd:
mov cx, n ;move degree of polynomial into cx for loop
inc cx ;increment cx to access all elements in the loop
mov ah, 9h ;Print string routine
lea dx, polyOut ;load into dx for Print
int 21h ;call DOS
lea si, myArray ;Load address of myArray into si
lea bp, polyStr ;Load address of polyStr into bp
poly_out:
mov ah, 2h ;print char sub routine
mov dl, [si] ;load coefficient for printing
int 21h ;call DOS
mov ah, 9h ;print string sub routine
mov dx, bp ;load polyStr for print
int 21h ;call DOS
mov ah, 2h ;print char sub routine
mov dx, cx ;move the degree of poly for print
add dx, 30h ;Ascii offset
dec dx ;adjust to real value (loop is cx+1)
int 21h ;call DOS
mov dx, 43 ;+ symbol for printing
int 21h ;call DOS
add si, 2 ;move to the next coefficient
dec cx ;decrease cx for loop
cmp cx, 1 ;compare if cx is 1
je end_test ;if cx=1 jump to end_test to print last coefficient without degree and + sign
jmp poly_out
end_test:
mov ah, 2h ;print char sub routine
mov dx, lastin ;load last coefficient into dx for printing
int 21h ;call dos
mov ah, 2h ;
mov dx, 0ah ;Print new Line
int 21h ;
mov ah, 9h
lea dx, polyFinal
int 21h
mov cx, n ; for loop
mov bx, cx ; for output
add bx, 30h ;Ascii offset
lea si, myArray ;Load address of myArray into si
loop_2S:
mov ah, 2h ;print char sub routine
mov dx, 40 ;Print '('
int 21h ;call dos
mov dx, bx ;Print n of x^n
int 21h ;call dos
mov dx, 42 ;Print '*'
int 21h ;call dos
mov dx, [si] ;Print coefficient
int 21h ;call dos
mov dx, 41 ;Print '*'
int 21h ;call dos
mov ah, 9h
lea dx, polyStr ;Print '*x^'
int 21h ;call dos
mov ah, 2h
mov dx, cx
add dx, 30h
sub dx, 1
int 21h
mov ah, 2h
mov dx, 43 ;print "+"
int 21h ;call dos
add si, 2 ;point to next num in array
dec bx ;dec bx
dec cx ;dec cx
cmp cx, 0 ;
je end_all ; if cx=0 jump end_all
jmp loop_2S ; else jump loop_2S
end_all:
mov ah, 2h
mov dx, 48 ;print "+"
int 21h ;call dos
;-------------------------------------------------------------------------------------------------------------------------------------------------------
mov ah, 4ch ;Set up code to specify return to dos
int 21h ;Interpt number 21 (Return control to dos prompt)
;procedure to read the degree of the polynomial
;Input : None
;output : Stored in n
get_poly proc
push ax ;Back up ax
mov ah, 9h ;print string sub routine
lea dx, outStr ; load outStr for print
int 21h ; call dos
mov ah, 1 ;Specify Keyboard input with echo routine
int 21h ;Request service from the OS
mov ah, 0 ;Clear ah to store in memory
sub al, 30h ;Convert al to number
mov n, ax ;Put ax into n
mov ah, 2 ;Specify character output
mov dl, 0ah ;Specify new line
int 21h ;call DOS
pop ax ;Restore ax
ret
get_poly endp
;procedure to read the coefficient of the polynomial
;Input : bx pointing to memory location of myArray
;output :Stored in myArray and the last input when this proc was called stored in lastin
get_int proc
push ax ;Back up ax
mov ah, 1 ;Specify Keyboard input with echo routine
int 21h ;Request service from the OS
mov ah, 0 ;Clear ah
sub al, 30h ;Convert al to number
mov [myArray+bx], ax ;Store input into array location
add byte ptr [myArray+bx], 30h ;Ascii offset
mov lastin, ax ;Store input into lastin
add lastin, 30h ;Ascii offset
mov ah, 2 ;Specify character output
mov dl, 0ah ;Specify new line
int 21h ;call Dos
pop ax ;Restore ax
ret
get_int endp
code ends
end start
;-------------------------------------------------------------------------------------------------------------------------------------------------------
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