Invalid conversion from unsigned char* to char*

Here is a code -

  1 int main(int argc, char *argv[])
  2 {
  3     signed char S, *psc;
  4     unsigned char U,  *pusc;
  5     char C, *pc;
  6 
  7     C = S;
  8     C = U;
  9 
 10     pc = psc;
 11     pc = pusc;
 12 
 13     return 0;
 14 }

$ gcc test.cpp -o a
test.cpp: In function ‘int main(int, char**)’:
test.cpp:10:7: error: invalid conversion from ‘signed char*’ to ‘char*’ [-fpermissive]
test.cpp:11:7: error: invalid conversion from ‘unsigned char*’ to ‘char*’ [-fpermissive]

This is compiled on gcc version 4.6.3 on Ubuntu 12.10 on an Intel 32-bit machine.

Considering that char type is unsigned char on x86. -

If assignments on line 7 and 8 for non-pointer types are Ok, why errors are thrown for pointer types on lines 10 and 11 ?

Also, should C = U succeeds without requiring a cast?