Ant Attack: Routine at 8060

8060: Read the movement keys into the player's record

Used by the routine at MOVE_PLAYER.

V (move) and C (jump) become bits 2 and 1 of the flags at +7, in one go. SYMBOL SHIFT and M turn the player, but only when not stunned.

Input
IX	The player's record

READ_CONTROLS

8060

LD BC,$FEFE

CAPS SHIFT to V, made active high: C is bit 3, V bit 4.

8063

IN A,(C)

8065

CPL

8066

AND $18

Down to bits 1 and 2: jump and move.

8068

RRCA

8069

RRCA

806A

LD E,A

Replace the player's jump and move bits with them.

806B

LD A,(IX+$07)

806E

AND $F9

8070

OR E

8071

LD (IX+$07),A

8074

LD A,(IX+$06)

Stunned: no turning.

8077

AND A

8078

RET NZ

8079

LD B,$7F

SPACE to B: SYMBOL SHIFT is bit 1, M bit 2.

807B

IN A,(C)

807D

CPL

807E

AND $06

8080

CP $02

SYMBOL SHIFT alone: turn one way...

8082

JR NZ,READ_CONTROLS_0

8084

DEC (IX+$04)

8087

RET

READ_CONTROLS_0

8088

CP $04

...M alone: the other.

808A

JR NZ,READ_CONTROLS_1

808C

INC (IX+$04)

READ_CONTROLS_1

808F

RET