view basic/makeflot.c @ 115:54b4e3afcd0e

Added tag current for changeset bc9f2f443421
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Tue, 01 Jan 2019 08:57:35 +0900
parents 2088fd998865
children
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line source

/* This program converts floating point numbers to
   the 5-bit binary representation used in 6809 BASIC.
*/

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <ctype.h>
#include <string.h>

main()
{
 double num;
 char line[128],label[128];
 unsigned char byte[5];
 int expo,sign,i;
 unsigned long mant;
 label[0]=0;
 printf("* These are the floating point constants.\n");
 printf("* They are generated by the program makeflot.c\n");
 while(fgets(line,128,stdin)) {
  line[strlen(line)-1]=0;
  if(!line[0])continue;
  if(line[0]=='*'){printf("%s\n",line);continue;}
  if(isalpha(line[0])) {
   sscanf(line,"%s",label);
  }else{
   sscanf(line,"%lf",&num);
   if(num==0) {
    sign=0;
    expo=0;
    mant=0;
   }else{
    sign=0x80*(num<0);
    num=fabs(num);
    expo=0x9f;
    while(num<2147483648.0){
     num=num*2;
     expo-=1;
    }
    while(num>=4294967296.0){
     num=num/2;
     expo+=1;
    }
    mant=num+0.5;
   }  
   byte[0]=expo;byte[1]=((mant>>24)&0x7f)+sign;
   byte[2]=((mant>>16)&0xff);byte[3]=((mant>>8)&0xff);byte[4]=mant&0xff;
   printf("%-16s fcb $%02x,$%02x,$%02x,$%02x,$%02x ;%s\n",
    label,byte[0],byte[1],byte[2],byte[3],byte[4],line);
   label[0]=0;
  }
 }
 printf("* End of floating point constants.\n"); 
 exit(0);
}