F-128          ;7
QP
  LD  A,(P_B)
  AND B
  LD  (P_B),A

  LD  A,(P_R)
  AND B
  LD  (P_R),A

  LD  A,(P_G)
  AND B
  LD  (P_G),A

  LD  A,B
  CPL
  LD  B,A

  LD  C,0
  LD  DE,0
  LD  A,L
  RRA
  IF  C THEN LD C,B
  RRA
  IF  C THEN LD D,B
  RRA
  IF  C THEN LD E,B

  LD  B,$10
  LD  A,(P_B)
  OR  C
  OUT (C),A
  LD  (P_B),A

  INC B
  LD  A,(P_R)
  OR  D
  OUT (C),A
  LD  (P_R),A

  INC B
  LD  A,(P_G)
  OR  E
  OUT (C),A
  LD  (P_G),A

  POP HL
  POP DE
  POP BC
  RET


PRESS:
  ;<  BC=kʒl(B=Y,C=X)   X=0-79,Y=0-24
  ;<  DE=k͈(D=X,E=Y)   X=1-80,Y=(1-25)*8
  ;<  HL=DATA ɳ ADDR
  ;x  ALL
  LD  A,120
  LD  (CP),A
  XOR A
  LD  (KZ),A
  LD  (STOCK),A

  LD  (HL),E
  INC HL
  LD  (HL),D
  INC HL
