1704
;;Conv.MAC
;;==== Various conversion routines


;;TITLE Dec2Hex.MAC
;;==== converts decimal value in 'buff' to HEX and stores it in DX
;;--------------------------------------------------------------------------

dec2hex MACRO buff
        LOCAL convert,ready

        push ax
        push bx
        push cx
        push di

        mov di,OFFSET buff
        sub ax,ax
        sub dx,dx        
        sub bx,bx

convert:
        mov bl,byte ptr[di]
        inc di
        cmp bl,0
        je ready

        sub bl,030h

        mov cx,0ah
        mul cx
        add ax,bx

        jmp convert

ready:
        mov dx,ax                               ;;Place result in DX

        pop di
        pop cx
        pop bx
        pop ax

        ENDM

;;-------------------------------------------------------------------------

;;===== Hex2Dec.MAC
;;====== Converts value in DX to Decimal
;;---------------------------------------------------------------------

Hex2Dec MACRO buff
        LOCAL Kvot_0,Slut,fill_buf,Go_On,Over_fill

        push ax
        push cx
        push di

        call fill_buf

        mov di,OFFSET Buff+1

        cmp dx,0000h
        jnz Kvot_0

        mov byte ptr[di],'0'                    ;;¸tminstone ETT v„rde
        jmp Slut 


Kvot_0:
        mov ax,dx                               ;;Hex-talet -> AX
        mov dx,0000h                            ;;Nollst DX ('Rest')

        mov cx,0ah                              ;;10 -> CX ('N„mnare')
        div cx                                  ;;Operation AX/CX
                                                ;;Kvot -> AX och Rest -> DX
        xchg ax,dx                              ;;Kvot -> DX, Rest -> AX

        add al,30h                              ;;HEX -> ASCII
        mov [di],al                             ;;ASCII-v„rdet sparas
        inc di                                  ;;N„sta cell pekas ut

        cmp dx,0000h                            ;;Kvoten i div = 0 ?
        jnz Kvot_0                              ;;Forts„tt tills kvot = 0

Slut:
        jmp Over_fill

fill_buf PROC NEAR

        mov di,OFFSET Buff
        mov ax,0000h

Go_On:
        mov byte ptr[di],al
        inc di
        inc ah
        cmp ah,07h
        jnz Go_On
        ret

fill_buf ENDP
        
Over_fill:
        pop di
        pop cx
        pop ax

        ENDM

;;--------------------------------------------------------------------------

;;TITLE Hex2Bin.MAC
;;===== Writes out value in DX in binary form
;;------------------------------------------------------------------------

Hex2Bin MACRO
        LOCAL  Next_Bit,Bit_0,No_Spc,Quit

        push ax
        push bx
        push cx

        mov ax,dx                       ;;Word -> ax
        mov cl,0fh                      ;;Bit Counter
        mov bx,8000h                    ;;Mask which is shifted right
                                        ;;for each turn

Next_Bit:
        and ax,bx                       ;;Do masking
        cmp cl,00h                      ;;Bit 0?
        jz  Bit_0                       ;;if so, don't shift

        shr ax,cl                       ;;Make result 0/1

Bit_0:
        add al,30h                      ;;Against ASCII
        push dx                         ;;Save DX temporarily
        mov dl,al                       ;;Write bit
        mov ah,02h
        int 21h

;;------ Space Bit 7 & Bit 8 -----------------------------------

        cmp cl,08h
        jnz No_Spc

        mov dl,' '
        mov ah,02h
        int 21h

;;----------------------------------------------------------------

No_Spc:
        pop dx                          ;;Now we can fetch DX

        dec cl                          ;;Decrement bit counter
        cmp cl,-1                       ;; = -1?
        jz Quit                         ;; if so, quit

        shr bx,1                        ;;Shift mask 1 step right
        mov ax,dx                       ;;Word -> AX
        jmp Next_Bit

Quit:
        pop cx
        pop bx
        pop ax

        ENDM
;;=====================================================================

        
;;-------------------------------------------------------------------------

;;TITLE Bin2Hex.MAC
;;====== Rutinen h„mtar bin„ra tecken fr†n 'Bin_buf', konverterar till
;;====== HEX och sparar v„rdet i DX.
;;====== Tecknen h„mtas fr†n dataareans topp och g†r ner†t.
;;====== Buffern skall b†de b”rja och sluta med 00.
;;-------------------------------------------------------------------------

Bin2Hex MACRO bin_buf
       LOCAL Next_Adress,Next_Char,No_add,Klart,Slut

        push ax
        push cx
        push di

        mov di,OFFSET (bin_buf+1)

;;--------- H„r best„ms bufferns storlek -----------------------

Next_adress:
        mov dl,[di]                     ;;H„mta tecken
        cmp dl,00h                      ;;0?
        jz  Klart
        inc di
        jmp Next_Adress

Klart:
        dec di

;;----- Konvertering till Hextal, l„ggs i DX ----------------------------

        mov dx,0000h                    ;;Nollst„ll DX
        mov cx,0001h                    ;;Initiera multiplicerare

Next_char:
        mov al,[di]                     ;;Tecken -> DL i ordn
                                        ;;MSB -> LSB
        cmp al,00h
        jz Slut

        sub al,30h
        cmp al,0
        jz No_add
        add dx,cx
No_add:
        dec di                          ;;Peka p† n„sta tecken
        sal cx,1                       
        jmp Next_Char

Slut:
        pop di
        pop cx
        pop ax

        ENDM

;;---------------------------------------------------------------------------         

        
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