matrixmult.asm

;read size of first matrix into r0,r1
movx a,@dptr
mov r0,a
inc dptr
movx a,@dptr
mov r1,a
inc dptr
;move start of matrix to r2
mov r2,dpl

;read size of second matrix into r3,r4
mov a,#10h
mov dpl,a
movx a,@dptr
mov r3,a
inc dptr
movx a,@dptr
mov r4,a
inc dptr
;start of second matrix to r5
mov r5,dpl

;see if they are multiplicable
mov a,r1
subb a,r3
jz next
;can't multiply
mov a,#20h
mov dpl,a
mov a,#0ffh
movx @dptr,a
jmp ende
next:
;result dptr is in tl0
;set result size
mov tl0,#20h
mov dpl,tl0
mov a,r0
movx @dptr,a
inc dptr
mov a,r4
movx @dptr,a
inc dptr
mov tl0,dpl
;i going from 0 to r0-1 (i=r7)
mov r7,#0
outer:
	;j going from 0 to r4-1 (j=r6)
	mov r6,#0
	inner:
		;sum 0 (sum=th0)
		mov th0,#0
		;k going form 0 to r1-1 (k=th1)
		mov th1,#0
		ininner:
			;sum+= a[i][k] + b[k][j]
			;a[i][k]=a+i*n+k = r2 + r7*r1 + th1
			mov a,r7
			mov b,r1
			mul ab
			add a,r2
			add a,th1
			mov dpl,a
			;read a[i][k] to tl1
			movx a,@dptr
			mov tl1,a

			;b[k][j]=b+k*n+j = r5 + th1*r4 + r6
			mov a,th1
			mov b,r4
			mul ab
			add a,r5
			add a,r6
			mov dpl,a
			;read a[k][j] to tl1
			movx a,@dptr
			mov b,tl1
			mul ab
			; add this product to sum (th0)
			mov b,th0
			add a,b
			mov th0,a
			; loop innner till k(th1) is r1
			inc th1
			mov a,th1
			clr c
			subb a,r1
			jnz ininner
		;c[i][j] = sum
		;c[i][j] = c + i*n + j = tl0 + r7*r1 + r6
		mov a,r7
		mov b,r1
		mul ab
		add a,tl0
		add a,r6
		mov dpl,a
		;print sum
		mov a,th0
		movx @dptr,a
		inc th0
		;loop till inner till j = r4
		inc r6
		mov a,r6
		clr c
		subb a,r4
		jnz inner
	;loop till outer till i = r0
	inc r7
	mov a,r7
	clr c
	subb a,r0
	jnz outer
ende:
sjmp ende