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1. • 1: CommentAuthorw1k
   • CommentTime14 Apr 2010 19:04 zmieniony

    
   how can i do in asm this?
   for i=1 to 10:?i:next i
   
   how i count from 1 to 10?
   
   i have this example:
   

   run $2000
   	org $2000
   
   	ldx #0
   loop	inx
   	stx $bc40
   	jmp loop
   

   
   
   then o mod it:
   

   clc
   	lda #0
   loop adc #1
   	cmp #10
   	sta $bc40
   	bne loop
   end
   

   
   
   not work..
2. • 2: CommentAuthormono
   • CommentTime14 Apr 2010 20:04 zmieniony

    

   scrad equ $58 ;.w
   adr equ $80 ;.w
   
     ldx scrad
     ldy scrad+1
     stx adr
     sty adr+1
     ldx #0
     ldy #0
   loop:
     iny
     tya
     ora #$10
     sta (adr,x)
     lda #40
     adc adr
     sta adr
     bcc *+4
     inc adr+1
     cpy #10+1
     bcc loop
     rts
   

   
   
   Edit: Sorry - this code print ':' as 10 :( Look forward for better routine.
3. • 3:
      
     CommentAuthorPecus
   • CommentTime14 Apr 2010 20:04

    
   w1k: swap STA and CMP.
4. • 4: CommentAuthorw1k
   • CommentTime14 Apr 2010 20:04

    
   jesus..
   it's to hard to understand..:(
   why $80? (128?)
   can you comment that code please? thank you
5. • 5: CommentAuthormono
   • CommentTime14 Apr 2010 20:04 zmieniony

    
   @Pecus: sta don't touch flags - it's no problem.
   
   @w1k: $80..$ff is the user space area on zero page. You can free use these registers.
   
   But If you want to count and print 2-digit numbers then you need following code:
   

   scrad equ $58 ;.w - begin of screen
   adr equ $80 ;.w - my work register with address of screen row
   dec equ $82 ;.b - counter in bcd
   
     ldx scrad     ;move first screen row address
     ldy scrad+1   ;to work row address
     stx adr
     sty adr+1
     ldx #1        ;for i=1
   @loop:
     txa           ;convert binary number to bcd
     jsr bin2dec
   
     pha
     lsr @
     lsr @
     lsr @
     lsr @
     ora #$10      ;'0' internal code
     ldy #0        ;column #0
     sta (adr),y   ;print dec
   
     pla
     and #$f
     ora #$10      ;'0' internal code
     iny           ;column #1
     sta (adr),y   ;print units
   
     clc           ;calculate next screen row address
     lda #40       ;screen width
     adc adr
     sta adr
     bcc @pass
     inc adr+1
   @pass:
     inx           ;next i
     cpx #10+1     ;...to 10
     bcc @loop
     rts
   
   ;bin to bcd conversion
   bin2dec:
     ldy #0        ;clear work register
     sty dec
     ldy #8        ;count of bits in byte
     sed           ;bcd mode on
   @loop:
     asl @         ;bit shift work only as binary operator (multiplies by 2 in binary)
     lda dec       ;multiplies by 2 in bcd mode
     adc dec       ;and shift in C from binary number
     sta dec
     dey
     bne @loop
     cld           ;bcd mode off
     lda dec       ;dec has bcd value of A on input
     rts
   
6. • 6: CommentAuthortebe
   • CommentTime14 Apr 2010 20:04

    
   org $2000
   
   .var .byte i = 1
   
   #while .byte i<=#10
   
   ldx i
   
   lda #$ff
   sta $bc40,x
   
   inc i
   #end
   rts
7. • 7: CommentAuthorw1k
   • CommentTime14 Apr 2010 20:04

    
   hmm..
   if i'm a totally novice with asm, with which should i start?
8. • 8: CommentAuthormono
   • CommentTime14 Apr 2010 21:04

    
   I know only publications in Polish. IMHO best one is "Assembler 6502" by Jan Ruszczyc ->link<- . Memory map is described in "Mapping of the Atari", but system is detailed in books of Wojciech Zientara ->link<- . Unfortunatelly all (but "Mapping of the Atari") in Polish.
9. • 9: CommentAuthorw1k
   • CommentTime14 Apr 2010 21:04

    
   i understand polish.. tommorow i starting learn
   (czech/slovak books is it too poor for informations)
10. • 10: CommentAuthor0xF
    • CommentTime15 Apr 2010 09:04

     

    w1k:

    then o mod it:
    

    clc
    	lda #0
    loop adc #1
    	cmp #10
    	sta $bc40
    	bne loop
    end
    

    
    

    
    
    Actually it works, but the whole program completes in a 1/15000 of a second. That's why you see just the final result, which is one character of ANTIC code 10.
    
    If you're switching from BASIC, keep in mind that asm is thousands times faster.
    
    The book by Ruszczyc is the best for beginners.
11. • 11:
       
      CommentAuthorjhusak
    • CommentTime15 Apr 2010 09:04

     
    @w1k - twój przykład:
    run $2000
    org $2000
    
    ldx #0
    loop inx
    stx $bc40
    jmp loop
    
    nie działa, bo jest nieskończona pętla.
    
    Twój drugi przykład działa natomiast dobrze, chociaż warto zawsze rozkazy zmieniające flagi (zero flag w tym przypadku Cię interesuje z powodu BNE) ustawiać bezpośrednio PRZED instrukcjami je sprawdzającymi (BNE w tym przypadku).
12. • 12: CommentAuthorxxl
    • CommentTime15 Apr 2010 10:04

     
    org $bc40
    dta $11
    org $bc40
    dta $12
    org $bc40
    dta $13
    org $bc40
    dta $14
    
    itd.
13. • 13: CommentAuthorilr
    • CommentTime15 Apr 2010 13:04

     
    Wiele ciekawych pozycji książkowych jest na stronie atariarchives.org.
    Między innymi:
    Machine Language For Beginners
    Assembly Language Programming for the Atari Computers
    Mapping The Atari - Revised Edition