Getting decimals

[roivic]

Am working on an ALP(for 8086) which is meant to calculate and display the averages of students on different courses offered. After calculations, i want the averages to be displayed in this format: 58.9 60.2 30.8... etc. but the DIV operation only keeps the remainder and not the decimal. which implies that an arithmetic 3/2 will result 1 remainder 1 instead of 1.5. How do i get the decimal?

[jj2007]

Multiply by 10, insert a dot.

[roivic]

Which? the integer or the remainder?

[dedndave]

calculate the (average X 10)
that will give you numbers like 589 602 308... etc
then, you insert the decimal point as text to get 58.9 60.2 30.8... etc

[Gunther]

Hi roivic,

welcome to the forum. To your question: for the 8086, the dividend has to be in AX, the divisor can be a memory location or another register. The result is in AX, the remainder in DX. Hope that helps. You'll find this information inside the Intel or AMD manuals (that download is a MUST).

Gunther

[hool]

masm32.com/board/index.php?topic=1226.15

[roivic]

Thanks, i already know the result stays in AX and the remainder stays in DX, my problem is actually how to convert the remainder to decimal. e.g these instructions

• MOV AX, 3H
• MOV BX, 2H
• DIV BX

leaves 1H in AX and 1H in DX but i want my answer as 1.5

[roivic]

Thanks hool, followed the link but it kind of look complex :(

[Gunther]

Hi  roivic,

Thanks, i already know the result stays in AX and the remainder stays in DX, my problem is actually how to convert the remainder to decimal. e.g these instructions

• MOV AX, 3H
• MOV BX, 2H
• DIV BX

leaves 1H in AX and 1H in DX but i want my answer as 1.5

I understand. An easy way to do that is to use floating point numbers and the FPU will bring you the right result. Check out Ray's FPU tutorial http://www.website.masmforum.com/tutorials/fptute/

Gunther

[dedndave]

Code Select Expand

    mov     ax,3
    mov     bx,10
    mul     bx
    mov     bl,2
    div     bx

;ax = 15

;additional code to round to nearest

    shl     dx,1
    cmp     dx,bx
    sbb     ax,-1

now, when you convert AX to ASCII decimal, you will get 15
you can insert a decimal point to make it 1.5

[roivic]

Ok thanks