; EAX contains number
; ebx contains place to store it and will hold last used spot when done
int_to_str PROC near
       push   ebp
       mov    ebp,esp
       sub    esp,4  
storebx  equ      [ebp-4]

       push   EAX
       push   ecx
       push   edx
       mov    storebx,ebx
       cmp    eax,80000000h
       je     negone ; This algorithm fails on largest negative
       cmp    eax,0
       jnl    pos
;  num is positive
       mov    cl,'-'
       neg    eax
       jmp    bypass
pos:
       mov    cl,' '
bypass:
; EAX is positive now go for it
       mov    ch,0
       mov    ebx,10
whileloop:
       cdq             ; increase EAX to EDX:EAX
       idiv   ebx      ; EAX gets quotient, EDX remainder
       add    dl,'0'   ; should be in range 0-9
       inc    ch
       push   dx       ; save the digit
       cmp    eax,0
       jnz    whileloop
         
       mov    ebx,storebx
; Now construct the string
       cmp    cl,'-'
       jne    nums
; insert minus sign
       mov    [ebx],cl
       inc    ebx

nums:
       shr    ecx,8     ; shift the count down and get rid of sign

numstart:
       pop    ax  
       mov    [ebx],al
       inc    ebx
       loop   numstart
i2sdone:
       pop    edx
       pop    ecx
       pop    eax
       mov    esp,ebp
       pop    ebp       
       ret
negone:
       mov    BYTE PTR [ebx],'-'
       inc    ebx
       mov    Byte PTR [ebx],'I'
       inc    ebx
       mov    BYTE PTR [ebx],'n'
       inc    ebx
       mov    Byte PTR [ebx],'f'
       inc    ebx
       jmp    i2sdone
int_to_str endp