/* Numerical I/O Routines for Small C */

#asm
ccnbuff: DEFS 10 ;I/P buffer
#endasm

/*
getdec()        Inputs a decimal number. Uses ccnbuff as I/P buffer
putdec(n)       Outputs a decimal number
gethex()        Inputs a hex number. Uses ccnbuff as I/P buffer
putbyte(ch)     Outputs an 8 bit number as 2 hex digits
puthex(n)       Outputs a 16 bit number as 4 hex digits
atoi(ptr)	Returns an integer from ASCII pointed to by ptr
hextoi(ptr)	......................from hex ASCII no ........
*/

/*
I/P a signed decimal number
*/
getdec()
{
char *ptr;
ptr=ccnbuff;
putchar('?'); /* Prompt */
gets(ptr);
return atoi(ptr);
}
/*
Get char. from buffer, check if numeric and return value or -1 
*/
ccnum(ptr)
char *ptr;
{char c;
c=*ptr&127; /* Mask off top bit */
if((c<'0')|(c>'9')) return -1;
return c-'0';}

/*
Output a signed decimal number
*/
putdec(n)
int n;
{if(n<0){n=-n; putchar('-');}
 if((n/10)!=0)
 putdec(n/10);
 putchar(n%10+'0');
}

/*
Input a hex number. Similar to getdec()
*/
gethex()
{int digval,n;
char *ptr;
n=0;
ptr=ccnbuff;
putchar('$'); /* Prompt */
gets(ptr);
while(*ptr==32)ptr++;
while(*ptr)
{digval=cchex(ptr++);
 if(digval==-1)break;
 n=digval+n*16;}
return n;}
/*
Get char. from buffer. Check if hex. Return value or -1 
*/
cchex(ptr)
char *ptr;
{char c;
c=*ptr&127;
if((c>='0')&(c<='9')) return c-'0';
if((c>='A')&(c<='F')) return c-55;
if((c>='a')&(c<='f')) return c-87;
return -1;}

/*
Output a byte in hex
*/
putbyte(byte)
char byte;
{ char temp;
  temp=(byte>>4)&15;
  ccptnib(temp);
  temp=byte&15;
  ccptnib(temp);}

/*
Output nibble
*/
ccptnib(ch)
char ch;
{ if(ch<10)putchar(ch+48);
  else putchar(ch+55);}

/*
Output a 16 bit hex number
*/
puthex(ptr)
char *ptr;
{ char temp;
  temp=ptr>>8;
  putbyte(temp);
  temp=ptr;
  putbyte(temp);}

/*
Get a signed integer from a string in memory
*/
atoi(ptr)
char *ptr;
{int digval,sign,n;
n=0;
sign=1;
while(*ptr==' ')ptr++;
if(*ptr=='-'){sign=-1;ptr++;}
while(*ptr)
{digval=ccnum(ptr++);
 if(digval==-1)break;
 n=digval+n*10;}
return n*sign;}

/*
Get hex value from string in memory
*/
hextoi(ptr)
char *ptr;
{int digval,n;
 n=0;
 while(*ptr==' ')ptr++;
 while(*ptr)
 {digval=cchex(ptr++);
  if(digval==-1)break;
  n=digval+n*16;}
 return n;
}
CONFG),A ;Mark as CON:
 JP ccsxt ;back with channel 1 in HL
;  Set up g