Routines
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BF66: Test Pickup Drop Key
Used by the routines at HandlePickupAndDrop and CheckActionKeyReleased.
Tests if the key for picking up and dropping objects is being pressed. There is a way to read it from a different bit when the control method has bit 3 set, but nothing ever sets that bit.
Output
F Zero flag clear if the key is being pressed
Use a different bit when the control method has bit 3 set.
TestPickupDropKey BF66 LD HL,$A709 Take the control method, ControlMethod.
BF69 LD A,(HL) Fetch the control method.
BF6A AND %00000110 Keep only the bits that choose a joystick.
BF6C LD A,($A737) Fetch the controls from ControlsPressed.
BF6F JR Z,TestPickupDropKey_Mask Jump to TestPickupDropKey_Mask if the keyboard is being used.
BF71 BIT 3,(HL) Jump to TestPickupDropKey_Mask if bit 3 of the control method is not set.
BF73 JR Z,TestPickupDropKey_Mask
BF75 RRCA Shift the bits of the controls down by one place.
Keep only the pick-up and drop bit.
TestPickupDropKey_Mask BF76 AND %00010000 Keep only the bit for picking up and dropping.
BF78 RET Return.
View the equivalent code in;
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