🚀 go-pugleaf

In article <1992Dec18.094825.14710@miavx1.acs.muohio.edu> sjmadsen@apsvax.aps.muohio.edu (Steve Madsen) writes:
>Michael Duffy (mduffy@aludra.usc.edu) wrote:
>: The following code gives me a divide error:
>: 
>:  mov  ax,0035h
>:  mov  dx,01h
>:  div  dx
>:
>
>	I'm not a genius at assembler, but after looking in my TASM 3.2
>quick-ref, this is about the only thing I could come up with:
>
>	What it appears is that you are doing a simple 16-bit divide.
>As far as my manual is concerned, if you do a div instruction with a
>16-bit operand (such as dx in your example), then it uses DX:AX as your
>dividend.  This might be why you are having a problem, but it's only a
>guess.
>
>	You could try changing DX to DL and see if that works.  Since
>you are assigned DX to what looks like a byte value anyway, this might
>solve your problem. 

You are getting divide errors because the quotient cannot be stored within
a 16 bit registers (ie. AX).  Division on an 80x86 stores the quotient in AX
and the remainder in DX assuming that you are performing 16 bit divisions.
I think that you have to check that the quotient will not be larger than
16 bits before performing the division.