; Q2i=N5i/4-N6i
; Q2i=(N5i-N6i)*2
; Q2 = ( sum( i = 1 to N ) of Q2i ) / N + K.

N           equ     3           ; Kol-vo chisel v massive, >= 10.
K           equ     0           ; Proizvol'naya konstanta.

dseg        at      30h         ; Segment dannih.
N5:         ds      2           ; Adres elementa i v n5.
N6:         ds      2           ; Adres elementa i v n6.
Sum:        ds      2           ; Summa.
Remainder:  ds      2           ; Ostatok.
Remainder4: ds      1           ; Ostatok.pri del na 4
sum_rem:        ds      2           ; Sum ostatok pri del na 4
DivResult:  ds      2           ; Resultat deleniya.

xseg                            ; Segment vneshney pamyati.
Q2:         ds      2           ; Finalnyi rezultat.

cseg                            ; Segment koda.
            jmp     start       ; Perehod na start.
            org     40h


N5Arr:      dw      41,42,9
N6Arr:      dw      5,4,4

start:
            mov     r2,#N       ; Schetchik iteraciy.

            ; Zanesti znacheniya massivov:
            mov     N5,#High(N5Arr)
            mov     N5+1,#Low(N5Arr)
            mov     N6,#High(N6Arr)
            mov     N6+1,#Low(N6Arr)

            mov     sum,#0h     ; Obnulenie summy.
            mov     sum+1,#0h

division4:
            ; Perenosim N5i v r3r4
            mov     dph,N5      ; Zanesti adres v registr kosvennoy adresacii.
            mov         dpl,N5+1
            clr     a           ; Ochistit' a.
            movc    a,@a+dptr   ; Peresylka iz pamyati programmy.
            mov     r3,a        ; Zanesenie v r3.
            clr     a           ; Ochistit' a.
            inc     dptr        ; Uvelichit' znachenie ukazatelya.
            movc    a,@a+dptr   ; Peresylka iz pamyati programmy.
            mov     r4,a        ; Zanesenie v r4.
            clr     a           ; Ochistit' a.
            inc     dptr        ; Uvelichit' znachenie ukazatelya.
            mov     N5,dph      ; Peredvinut' ukazatel na massiv.
            mov     N5+1,dpl

            ; Perenosim N6i v r5r6
            mov     dph,n6      ; Zanesti adres v registr kosvennoy adresacii.
            mov     dpl,n6+1
            clr     a           ; Ochistit' a.
            movc    a,@a+dptr   ; Peresylka iz pamyati programmy.
            mov     r5,a        ; Zanesenie v r5.
            clr     a           ; Ochistit' a.
            inc     dptr        ; Uvelichit' znachenie ukazatelya.
            movc    a,@a+dptr   ; Peresylka iz pamyati programmy.
            mov     r6,a        ; Zanesenie v r6.
            clr     a           ; Ochistit' a.
            inc     dptr        ; Uvelichit' znahenie ukazatelya.
            mov     N6,dph      ; Peredvinut' ukazatel na massiv.
            mov     N6+1,dpl

            clr c
            mov a,r3
            rrc a
            mov r3,a
            mov a,r4
            rrc a
            mov r4,a

            clr a
            addc a,#0
            mov Remainder4,a

            clr c
            mov a,r3
            rrc a
            mov r3,a
            mov a,r4
            rrc a
            mov r4,a

            mov b,#2
            clr a
            addc a,#0
            mul ab

            add a,Remainder4
            mov Remainder4,a

            ;mov r7,a
            ;mov a,sum_rem
            ;add a,r7
            ;mov sum_rem,a

subtraction:

            ; Vichytanie mladshego baita i zanesenie rezul'tata v r4.
            clr     c           ; Ochistka flaga perenosa.
            mov     a,r4        ; Kopirovanie v akkumulyator.
            subb    a,r6        ; Vichytanie.
            mov     r4,a        ; Sohranenie rezul'tata.

            ; Vichytanie starshego baita i zaema i zanesenie rezul'tata v r3.
            mov     a,r3        ; Kopirovanie v akkumulyator.
            subb    a,r5        ; Vichytanie.
            mov     r3,a        ; Sohranenie rezul'tata.

            jnc nosubrem

            ;13.75-14 = -0.25
            ;100 = 4
            ;75 = 3
            ;50 = 2
            ;25 = 1
            ;this is for this
            clr c
            mov a,#4h
            mov r7,Remainder4
            subb a,r7
            mov Remainder4,a

            ;srazu vichitaem ego iz obshego ostatka potomuchto otric chislo
            clr c
            mov r7,Remainder4
            mov a,Remainder
            subb a,r7
            mov Remainder,a
            mov r7,a
            mov a,#0
            mov Remainder4,a

            ;SLUCHAY ESLI OSTATOK OTRIC
            mov a,r7
            anl a,#80h
            jz poloshostatok

            ;vichit 1 iz summ
            clr c
            mov a,sum+1
            subb a,#1
            mov sum+1,a
            mov a,sum
            subb a,#0
            mov sum,a
            ;obnov tek ostatok
            clr c
            mov a,Remainder
            add a,#4
            mov Remainder,a

poloshostatok:
            ;mov Remainder,a

            mov a,r4
            add a,#1
            mov r4,a

            mov a,r3
            addc a,#0
            mov r3,a

nosubrem:
            clr c
            mov a,Remainder
            addc a,Remainder4
            mov Remainder,a

            subb a,#4
            anl a,#80h
            jnz noaddrem

            mov a,r4
            add a,#1
            mov r4,a

            mov a,r3
            addc a,#0
            mov r3,a

            clr c
            mov a,Remainder
            subb a,#4
            mov Remainder,a

noaddrem:
            ; Summirovanie rezul'tata s Q2.
            mov     a,r4        ; Perenos mladhsego baita.
            add     a,sum+1     ; Summa s mladshim baitom.
            mov     sum+1,a     ; Vozvrat rezul'tata.

            mov     a,r3        ; Perenos starhego baita.
            addc    a,sum       ; Summa so starshim baitom.
            mov     sum,a       ; Vozvrat rezul'tata.

            clr c
            mov a,r2
            subb a,#1
            mov r2,a
            jz  endsub
            jmp division4   ; Provarka okonchaniya cikla.

endsub:

end