is this a bug Kiel 7.5 for 8051? The compiler is generation 0xFFE0 for -0x60

Yes I know that this is not a supported version, but I am trying to confirm whether this is a known bug:

This is a screen capture.  You can very clearly se the assignment of 0x60 at A959   and the adding of 0xE0 (A968) and A96C to do the subtraction, BUT: E0 is -0x20 NOT -0x60.

#define PRESET_START=0x60;
i=PRESET_START ; // result is that i does equal 0x60
i= variable - PRESET_START; // the machine code generated is an add of 0xFFE0
NOW: the last I knew, -0x60 is 0xFFA0 , NOT 0xFFE0