问题
I was given a task to convert decimal input numbers and output its binary equivalent via an "array" using assembly. I've the code complete and working, trouble is it only accepts numbers 0-99 for conversion.
Ideally, the program should be able to convert any number at least up to 255 decimal so that the code can be reusable for future practices where I might need to handle different 16 bit values within registers.
I appreciate all advice given, the code is as follows:
.model small
.stack
.data
;Variables used:
cad db 9 dup (' '),'$' ;Cad will contain the chain of bits
var1 db ? ;Var1 will be used to conver number
num db ? ;variable for input number
aux db ? ;auxiliary variable
msg db 10,13, "Enter decimal number 0-99: $", 10, 13
.code
.startup
mov ah,9
lea dx,msg
int 21h ;Shows first message
mov var1,0 ;Initializes var1 value to 0
mov ah,01h ;Int to obtain input
int 21h
sub al,30h ; Ascii code value to real decimal value conversion (subtracts 48d)
mov num,al ;Input number from AL is moved to variable num
mov al,num
mov bl,10 ;10 is stored in bl
mul bl ;Number to convert is multiplied by 10
mov aux,al ;aux variable is assigned the result
mov var1,0 ;We obtain the second user number input
mov ah,01h
int 21h
sub al,30h
add aux,al ;We add aux to the previous number multiplied by 10
mov bl,aux ;Doesn't need to be multiplied
mov num,bl ;result is stored in BL
mov ah,02h ;Prints '=' sign symbol after decimal input
mov dl,'='
int 21h
mov SI,6 ;Cycles where we use long division (Divide by 2)
L1: ;L1 label
xor Ah,Ah ;Resets AH
mov Al,num
mov Bl,2
div Bl
mov var1,Ah
mov num,Al
mov dl,var1
add dl,30h
mov cad[SI],dl;Concatenates results
cmp num,1 ;Compares num with 1
dec SI
jne L1 ;L1 loops until it goes through the all numbers
je exit ;exits loop
cmp num,0 ;Compares num with 0
jne L1
je exit
exit: ;exit label
mov dl,num ;prints the chain in binary
add dl,30h
mov cad[SI],dl
mov ah,09h
lea Dx,cad
int 21h
mov ah,4ch
int 21h
end
来源：https://stackoverflow.com/questions/52547515/decimal-to-binary-conversion-asm-3-digits