Whats the working difference between a signed char pointer and an unsigned one?

Question

I can understand the difference between a signed char and an unsigned one. But dont the pointers of the corresponding type equivalent in their operation? Cos sizeof(char) and sizeof(unsigned char) is always the same ( Or are there any counter examples? )

For pointers, only the size of the data type should matter. Are there any pitfalls if I use char * and unsigned char * interchangeably?

I din't find these posts as useful :(

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Answer 1

Here is a counter example based on the difference in ranges of types pointed by each pointer type:

#include <stdio.h>
int main() {
  unsigned char *uc;
  char *c;
  unsigned char v = 128;
  uc = &v;
  c  = &v;
  if (*uc != *c)
    printf("there is difference\n");
  return 0;
}