Mbin

 BBS: Inland Empire Archive
Date: 06-02-92 (19:20)             Number: 81
From: JEFF FREEMAN                 Refer#: NONE
  To: ROB FLOR                      Recvd: NO  
Subj: Mbin                           Conf: (2) Quik_Bas
RF>MH>If you still need conversion from the old Microsoft
RF>MH>Binary Format for use
  >in
  >  >PDQ, PDS and QB 4.x have built in conversion with
  >  >MKSMBF, MKDMBF, CVSMBF,
  >  >CVDMDF.  Looks like it would have to be a pre-PDQ conversion though.


RF>  It's me who is looking for an explaination of the format, and its to
  >convert to the old Microsoft Binary Format, not from.

RF>  I've wracked my books looking for a description which I'd seen
  >somewhere, and am hopeing someone on the echo will have something in a
  >reference book.  It probably wouldn't be in a QB reference since it's a
  >built in function, but a general programmers reference.

RF>  Someone at Cresent knows how to pack a number in MSBIN since they
  >added CVIMKS$ two months after I bought PDQ 2.2 (HINT HINT). :)

Single$ = MKSMBF$(x)
Double$ = MKDMBF$(x)

If 'x' is a different variable type than SINGLE or DOUBLE, it is first
converted by QB to a single (for MKSMBF$) or a double (for MKDMBF$).  So
use MKSMBF$ for single and integer variables, use MKDMBF$ for double and
Long-integer variables.

*OR* you can enter the QB environ' with the /MBF command line parameter
- this will make QB use the old MSBIN format instead of IEEE.  I.E.
MKS$, MKD$, CVS, CVD, will do what you want them to do.

If you absolutely have to write your own routine to do this, use this:

         /***  MSBIN conversion routines ***/

         union Converter
               {
                unsigned char uc[10];
                unsigned int  ui[5];
                unsigned long ul[2];
                float          f[2];
                double         d[1];
               }


         float MSBINToIEEE(float f)
         {
            union Converter t;
            int sign, exp;       /* sign and exponent */

            t.f[0] = f;

         /* extract the sign & move exponent bias from 0x81 to 0x7f */

            sign = t.uc[2] / 0x80;
            exp  = (t.uc[3] - 0x81 + 0x7f) & 0xff;

         /* reassemble them in IEEE 4 byte real number format */

            t.ui[1] = (t.ui[1] & 0x7f) | (exp << 7) | (sign << 15);
            return t.f[0];
         } /* End of MSBINToIEEE */



         float MSBINToIEEE(float f)
         {
            union Converter t;
            int sign, exp;       /* sign and exponent */

            t.f[0] = f;

         /* extract the sign & move exponent bias from 0x81 to 0x7f */

            sign = t.uc[2] / 0x80;
            exp  = (t.uc[3] - 0x81 + 0x7f) & 0xff;

         /* reassemble them in IEEE 4 byte real number format */

            t.ui[1] = (t.ui[1] & 0x7f) | (exp << 7) | (sign << 15);
            return t.f[0];
         } /* End of MSBINToIEEE */



         float IEEEToMSBIN(float f)
         {
            union Converter t;
            int sign, exp;       /* sign and exponent */

            t.f[0] = f;

         /* extract sign & change exponent bias from 0x7f to 0x81 */

            sign = t.uc[3] / 0x80;
            exp  = ((t.ui[1] >> 7) - 0x7f + 0x81) & 0xff;

         /* reassemble them in MSBIN format */

            t.ui[1] = (t.ui[1] & 0x7f) | (sign << 7) | (exp << 8);
            return t.f[0];
         } /* End of IEEEToMSBIN */


Knock yourself out.

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