Kempstone mouse driver - tre popular into Russia!


;XECUTE MOUSE
;TAKE COORDINATES FROM CURPOS==COORD

MOUSE LD HL,(COORD)
     LD BC,#FBDF
     LD DE,(OLDCO)
     IN A,(C)
     LD (OLDCO),A
     SUB E
     JR Z,NM_X
     JP P,MX_PL
     ADD A,L
     JR C,ZER_X
     XOR A
ZER_X LD L,A
     JR NM_X
MX_PL ADD A,L
     JR C,BEX_Z
     CP #FD ;MAXIMUM X
     JR C,BEX_B
BEX_Z LD A,#FD ;MAXIMUM X
BEX_B LD L,A
NM_X LD B,#FF
     IN A,(C)
     LD (OLDCO+1),A
     SUB D
     JR Z,NM_Y
     NEG
     JP P,MY_PL
     ADD A,H
     JR C,ZER_Y
     XOR A
ZER_Y LD H,A
     JR NM_Y
MY_PL ADD A,H
     JR C,BEY_Z
     CP #BE ;MAXIMUM Y
     JR C,BEY_B
BEY_Z LD A,#BE ;MAXIMUM Y
BEY_B LD H,A
NM_Y LD A,H
     CP #FF
     JR C,BIGY
     LD H,#FF
BIGY CP #02 ;MINIMUM Y
     JR NC,SMALY
     LD H,#02 ;MINIMUM Y
SMALY LD A,L
     CP #FF
     JR C,DIRY
     LD L,#FF
DIRY CP #02 ;MINIMUM X
     JR NC,DIMENS
     LD L,#02 ;MINIMUM X
DIMENS LD (COORD),HL
     LD BC,#FADF
     LD HL,CONTRB
     IN A,(C)
     CPL
     AND 7
     RLCA
     RLCA
     RLCA
     RLCA
     OR (HL)
     LD (HL),A
     RET

COORD    DEFW ? ;Position
OLDCO DEFW 0 ;WORKING

=== Cut ===

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!

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.

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                                          稬 ਢ⮬, .

