What does it mean when you have an "unresolved external symbol"? The manual claims that the variable is not PUBLIC, however, I don't see how that's the case. I am getting warnings L1 and L2 when I put the following line in one file:
sbit var1 = P1 ^ 7;
extern bit var1;
It appears to me that you can extern sbit if you follow the method on page 94 of the C51 compiler manual (under "Bit-addressable Objects"). Unfortunately, I must be doing something wrong because that method doesn't seem to work. (Although, as buggy as this Keil program seems to be, it wouldn't surprise if what I was doing was just what I was supposed to do, and the program just doesn't work...)