-5>5 is true since this is unsigned so A should be 4 now
4<<-5 is false since this is signed (like basic) so A is still 4
Is it outputting something else?
Unless my understanding of how signed comparisons work, the routine should always work.
xor a ;Make A zero
ld b,h ;H is saved for later
sbc hl,de ;The values are compared unsigned (carry flag)
ld h,a ;Command returns 1 or 0 so high byte is zeroed
rra ;Carry is put into bit 7 of a
xor b ;Bit 7 is xored with sign bit of original left argument
xor d ;Bit 7 is xored with sign bit of original right argument
rlca ;Bit 7 put into bit 0
and %00000001 ;Mask to make this a 1 or 0
ld l,a ;HL holds (sign1 xor sign2 xor comparison)
