Category : Files from Magazines
Archive : BCD.ZIP
Filename : BCDMAIN.C
Output of file : BCDMAIN.C contained in archive : BCD.ZIP
/*
** BCD floating-point test package.
** Some Assembly Required - April 1989
** -- Rick Grehan
**
** This is a "shell" you can use to experiment with the BCD
** package. It includes external definitions to the assembly-
** language routines and the source for the I/O routines
** (which I wrote in C). The I/O routines are pretty rudimentary,
** but should be useful for getting the numbers in and out.
**
*/
#include
#define BIAS 16384 /* BIAS for exponent */
typedef struct {
unsigned int exponent;
unsigned char mantissa[10];
} bcdtype ;
extern int fltadd();
extern int fltsub();
extern int fltmul();
extern int fltdiv();
extern int fltint();
extern int intflt();
main()
{
bcdtype bcd1,bcd2,bcd3;
int intout;
/*
* Just do some stuff.
*/
bcdin("+9.0E+00",&bcd1);
bcdout(&bcd1,10); printf("\n");
bcdin("3.00E+03",&bcd2);
bcdout(&bcd2,10); printf("\n");
fltadd(&bcd1,&bcd2,&bcd3);
bcdout(&bcd3,15); printf("\n");
if(fltint(&bcd3,&intout)==-1) printf("error\n");
printf("%d\n",intout);
if(intflt(intout,&bcd3)==-1) printf("error\n");
bcdout(&bcd3,15); printf("\n");
}
/*
** Output a BCD floating-point number.
** The number is output in the format:
** +/-n.nnnnE+/-mmm
** You can specify the number of digits in the mantissa.
*/
int bcdout(bcdnum,digs)
bcdtype *bcdnum;
int digs; /* Number of mantissa digits */
{
int i; /* Index */
unsigned char ch; /* Holding variable for each byte */
unsigned int truexp; /* True exponent */
/* Get true exponent and display mantissa sign */
truexp=((bcdnum->exponent)&0x7FFF)-BIAS;
if((bcdnum->exponent & 0x8000)==0)
printf("+");
else
printf("-");
/* Display mantissa digits */
for(i=0;i
ch=bcdnum->mantissa[i/2];
if(i % 2)
ch=ch & 15;
else
ch=ch >> 4;
printf("%c",ch+'0');
if(i==0) printf(".");
}
/* Display exponent */
printf("E%d",truexp-1);
return;
}
/*
** Input a BCD floating-point number.
** Pass this routine a pointer to a string and a pointer
** to a BCD structure. String is converted to BCD number.
** String MUST be in the following format:
** +/-n.nnnnE+/mmm
** You can have as many (up to the limit) n's to the right
** of the decimal point as you want.
** The function returns a 0 if conversion ok, -1 if conversion
** failed.
*/
int bcdin(stng,bcdnum)
unsigned char *stng;
bcdtype *bcdnum;
{
int i,j; /* Indices */
int sign; /* Sign of mantissa */
unsigned char ch; /* Holding var. for characters */
unsigned int truexp; /* True exponent */
int nd; /* # of digits to left of dpoint */
int dpfg; /* Decimal point flag */
/* Clear the BCD structure */
bcdnum->exponent=0;
for(i=0;i<10;++i)
bcdnum->mantissa[i]=0;
i=0;
j=0;
nd=0;
dpfg=0;
/* Look for the sign */
if(stng[i]=='-')
{ sign=1; ++i; }
else
if(stng[i]=='+')
{ sign=0; ++i; }
else
if(isdigit(stng[i]))
sign=0;
else
return(-1);
while(isdigit(stng[i]) || stng[i]=='.')
{
if(stng[i]=='.')
if(dpfg) return(-1);
else ++dpfg;
else
{
ch=stng[i] - '0';
if(j%2==0) ch=ch<<4;
bcdnum->mantissa[j/2] |= ch;
++j;
if(dpfg==0) ++nd;
}
++i;
}
if(stng[i]!='E') return(-1);
++i;
/* Get exponent */
sscanf(&stng[i],"%d",&truexp);
bcdnum->exponent=truexp+BIAS+nd;
bcdnum->exponent+=sign<<15;
return(0);
}
Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!
This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.
But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/