Routines
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B085: Read Interface 2
Reads the Sinclair interface 2 joysticks. The keys 06 to 00 are one joystick and the keys 01 to 05 are the other; both are used at once.
ReadInterface2 B085 LD A,$EF Read from the keyboard;
Port Number Bit
0 1 2 3 4
EF 0 9 8 7 6
B087 CALL ReadKeys
B08A LD C,A Keep the keys in C.
B08B LD A,$F7 Read from the keyboard;
Port Number Bit
0 1 2 3 4
F7 1 2 3 4 5
B08D CALL ReadKeys
B090 OR C Combine the keys of both.
B091 LD C,$00 Clear the controls.
B093 BIT 0,A Jump if the first key is not pressed (00 or 01).
B095 JR Z,ReadInterface2_Key2
B097 SET 3,C Set the bit for firing the second weapon.
ReadInterface2_Key2 B099 BIT 1,A Jump if the second key is not pressed (09 or 02).
B09B JR Z,ReadInterface2_Key3
B09D SET 2,C Set the bit for moving forward.
ReadInterface2_Key3 B09F BIT 2,A Jump if the third key is not pressed (08 or 03).
B0A1 JR Z,ReadInterface2_Key4
B0A3 SET 6,C Set the bit for the action key.
ReadInterface2_Key4 B0A5 BIT 3,A Jump if the fourth key is not pressed (07 or 04).
B0A7 JR Z,ReadInterface2_Key5
B0A9 SET 0,C Set the bit for turning right.
ReadInterface2_Key5 B0AB BIT 4,A Jump if the fifth key is not pressed (06 or 05).
B0AD JR Z,ReadInterface2_Finish
B0AF SET 1,C Set the bit for turning left.
ReadInterface2_Finish B0B1 JP FinishJoystickControls Jump to finish.
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