convert a decimal number into a binary number.

[supernicky]

hello,

I want to convert a decimal number into a binary number.
for example:

9.5 in a 32 bit binary number.

this number is to be read by a editbox-control.
maybe someone can help me.

thanks and greetings

nicky

[dedndave]

hi Nicky - welcome to the forum

what you probably want is a floating point value, or REAL4
a 32-bit binary integer has no place for digits after the decimal point

you can define 4-byte floating point values using REAL4...

Code Select Expand

fVal1   REAL4   9.5

now, things can be simpler if all your values have a single digit after the decimal point
you can multiply them all by 10 and store them as integers   :bg

[supernicky]

hello back

I'm from Germany and I have to apologize for my english.

I work with the masm32 package. of real4 I have not heard or read: (

The declaration is always done with the data-type dd
for example:

number1 dd 3.54

I would like to understand is how a decimal (3.54) represented in binary.

I've created this one editbox in a decimal number to be entered.
then I need to process the input and convert binary.

32bit is too small? I should take 80bit?

how do I convert a binary number from 3.54?

I'm no math genius

thanks and greetings, nicky

[dedndave]

you are dealing with floating point values because there are digits beyond the decimal point
the format is one of a few that are used by the FPU
you can do a lot of math with the FPU   :P
at first, it may seem overwhelming, but it isn't that difficult to learn
Ray has a good tutorial
the tutorial may be found in the masm32\tutorial\fputute folder
however, i think Ray has updated it since the masm32 package was put together
he also has a nice floating point library
for the most recent version, visit his site...
http://www.ray.masmcode.com/

your English is great   :bg

to read a value from the edit box, you will want to convert an ASCII numeric float string into real4 format
i think Ray's library has a function to do that

[qWord]

hi,
you can use CRT function crt_sscanf for reading an floatingpoint value in a string. However, using the macros a2r4() and a2r8() for converting is easier (these macros use sscanf):

Code Select Expand

...
myreal REAL4 ?
sz db "1234.5",0
...
mov eax,a2r4(ADDR sz)
m2m myreal,REAL4 ptr [eax]
(the macros return a pointer to a REAL4/REAL8 variable)

[baltoro]

Hi, SUPERNICKY,   
In one of my programs, I did something similar. qWord's approach is the best,...using the a2r4 macro.
In my program, I had several routines. It was overkill, but, I'm a novice, and I wanted it to be reliable.
I had a routine to check the that the value entered in the edit box was actually a string in the correct decimal format. This is important, because, a2r4 will fail, and, you won't know why. The second routine, I actually adapted from the atodw MASM routine. My routine is seriously bloated, but, returns about a dozen different error codes if the routibne fails, so you can determine why the code doesn't work correctly,...otherwise it returns a pointer to a REAL 4.