conversion number ascii

[rockyone]

Research example to convert a hexadecimal number in ASCII
ex :$1492 in $35, $32, $36, $36

[Anima]

Input: d0.w
Output: hexval

Code: Select all

tohex:
 lea hexval,a0
 move.l #'0000',(a0)+
_loop:
 moveq #$f,d1
 and d0,d1
 move.b hextbl(pc,d1),-(a0)
 lsr #4,d0
 bne _loop
 rts

hexval:
 dc.b 0,0,0,0,0
 
hextbl:
 dc.b '0123456789abcdef'


Edit: bug fix.

[rockyone]

Thank you Anima

[Anima]

Please note the fixed bug: lsr #8,d0 changed to lsr #4,d0

[rockyone]

yes, I saw, but I board not tested

In fact, I want the decimal value in bytes
$1492 =5266
in AsCII $35, $32, $36, $36

The decimal value of the number Would Be enough!

[Anima]

Input: d0.w (unsigned)
Output: decval

Code: Select all

todec:
 lea decval,a0
 move.l #'0000',(a0)+
 move.b #'0',(a0)+
_loop:
 ext.l d0
 beq _exit
 divu #10,d0
 swap d0
 add.b d0,-(a0)
 swap d0
 bra _loop
exit:
 rts

decval:
 dc.b 0,0,0,0,0,0


[rockyone]

thank you Anima
It is enough to add
add.b $30,(a0)

[rockyone]

I adapted to my needs.
how to optimize?
d1 = minimum 3 maximum 32000

Code: Select all

hex_ascii:
   moveq.l   #0,d2
   
decimal:
   ext.l      d1
   beq.s      ascii
   divu.w     #10,d1
   swap       d1
   lsl.l      #4,d2
   add.b      d1,d2
   swap       d1
   bra.s      decimal
      
ascii:
   move.b     d2,(a2)
   and.b      #$f,(a2)
   add.b      #$30,(a2)+
   lsr.l      #4,d2
   bne.s      ascii

   move.b     #$d,(a2)+
   move.b     #$a,(a2)+
   rts


[nanard]

I adapted to my needs.
how to optimize?
d1 = minimum 3 maximum 32000

Code: Select all

hex_ascii:
   moveq.l   #0,d2
   
decimal:
   ext.l      d1
   beq.s      ascii
   divu.w     #10,d1
   swap       d1
   lsl.l      #4,d2
   add.b      d1,d2
   swap       d1
   bra.s      decimal
      
ascii:
   move.b     d2,(a2)
   and.b      #$f,(a2)
   add.b      #$30,(a2)+
   lsr.l      #4,d2
   bne.s      ascii

   move.b     #$d,(a2)+
   move.b     #$a,(a2)+
   rts


I think your version has issues with numbers ending with 0. Like 1000. Because d2 will be 0 just after you write the last non zero digit.
There is a way to fix. add 1 to value stored in d2.

Code: Select all

   lsl.l      #4,d2
   add.b      d1,d2
+   add.b      #1,d2
   swap       d1
   bra.s      decimal
      
ascii:
   move.b     d2,d1
   and.b     #$f,d1
   add.b   #$2f,d1
   move.b   d1,(a2)+
-   move.b     d2,(a2)
-   and.b      #$f,(a2)
-   add.b      #$30,(a2)+
   lsr.l      #4,d2
   bne.s      ascii


[nanard]

see my own code, which works between 0 and 655359 (the result of divu.w has to fit in 16bit) :
https://github.com/miniupnp/AtariST/blo ... ply.s#L356

[rockyone]

Oh yes, I Was left with $1492

I had done some tests aléatoires..without zeros

would I have seen the bug quickly ?
with the probalitées than the number ends in zero ..


Google translate

[rockyone]

this should be better now
I do not know the address of (a2) when I wrote the Nombe ascii.
(A2)
- is an output buffer.
- Its address is odd or even at the beginning of the subroutine.
- No space before and after the number ascii

Code: Select all

hex_ascii:
   moveq.l   #0,d2
   
decimal:
   ext.l      d1
   beq.s      ascii
   divu.w     #10,d1
   swap       d1
   lsl.l      #4,d2
   add.b      d1,d2
   add.b    #1,d2             ;+1
   swap       d1
   bra.s      decimal
     
ascii:
   move.b     d2,(a2)       ; even or odd address
   and.b      #$f,(a2)
   add.b      #$2f,(a2)+      ; -1
   lsr.l      #4,d2
   bne.s      ascii

   move.b     #$d,(a2)+
   move.b     #$a,(a2)+
   rts


[rockyone]

always bored with the conversions.
How to convert back?

[nanard]

always bored with the conversions.
How to convert back?

you mean implementing atoi() ? just mulu #10 and add each digit...

[rockyone]

no
I resumed the same number as example
#5266 = #$1492
ascii conversion '35323636 ' good

Now, how to convert '32353636' to $1492


ca seems very complicated to me 68000.
Fortunately the number that interests me always begins in the twelfth bytes

I am bad
I obtained $5266

[nanard]

That's really simple :

Code: Select all

atoi:
  moveq.l #0,d0
  moveq.l #0,d1
.loop:
  move.b (a0)+,d1
  tst.b d1
  beq .end
  subi.b #$30,d1
  mulu.w #10,d0
  add.w d1,d0
  bra .loop
.end:
  rts


[rockyone]

Actually yes it is very simple.
Thanks for the help