Hmmmm,

I'm using V7. Here's what I get...

.
.
.
  11   1      
  12   1      TB8 = ~ PARITY('M'); 
  13   1      
  14   1      
  15   1      SBUF = 'M'; 
.
.
.
ASSEMBLY LISTING OF GENERATED OBJECT CODE


             ; FUNCTION main (BEGIN)
                                           ; SOURCE LINE # 5
                                           ; SOURCE LINE # 6
                                           ; SOURCE LINE # 12
0000 744D              MOV     A,#04DH
0002 A2D0              MOV     C,P
0004 B3                CPL     C
0005 929B              MOV     TB8,C
                                           ; SOURCE LINE # 15
0007 F599              MOV     SBUF,A
                                           ; SOURCE LINE # 16
0009 22                RET     

This looks about right to me. Check your .LST file and see what the generated assembly code looks like.

Jon