#include <serial.h>
 
 static char *bf;
-static char buf[12];
-static unsigned int num;
-static char uc;
 static char zs;
 
 static void out(char c)
 
 static void out_dgt(char dgt)
 {
-       out(dgt + (dgt < 10 ? '0' : (uc ? 'A' : 'a') - 10));
+       out(dgt + (dgt < 10 ? '0' : 'a' - 10));
        zs = 1;
 }
 
-static void div_out(unsigned int div)
+static void div_out(unsigned int *num, unsigned int div)
 {
        unsigned char dgt = 0;
 
-       num &= 0xffff; /* just for testing the code with 32 bit ints */
-       while (num >= div) {
-               num -= div;
+       while (*num >= div) {
+               *num -= div;
                dgt++;
        }
 
        va_list va;
        char ch;
        char *p;
+       unsigned int num;
+       char buf[12];
+       unsigned int div;
 
        va_start(va, fmt);
 
                        if (ch >= '0' && ch <= '9') {
                                w = 0;
                                while (ch >= '0' && ch <= '9') {
-                                       w = (((w << 2) + w) << 1) + ch - '0';
+                                       w = (w * 10) + ch - '0';
                                        ch = *fmt++;
                                }
                        }
                                        num = -(int)num;
                                        out('-');
                                }
-                               div_out(10000);
-                               div_out(1000);
-                               div_out(100);
-                               div_out(10);
-                               out_dgt(num);
+                               for (div = 1000000000; div; div /= 10)
+                                       div_out(&num, div);
                                break;
                        case 'x':
-                       case 'X':
-                               uc = ch == 'X';
                                num = va_arg(va, unsigned int);
-                               div_out(0x1000);
-                               div_out(0x100);
-                               div_out(0x10);
-                               out_dgt(num);
+                               for (div = 0x10000000; div; div /= 0x10)
+                                       div_out(&num, div);
                                break;
                        case 'c':
                                out((char)(va_arg(va, int)));