;============

;Change Map16

;============

CreateTile:

    	LDX #$12F0 ;tile to generate

	JSR ChangeMap16

	RTL



;The code itself.



PrematureEnd:

	PLX

	PLY

	PLB

	PLP

	RTS

ChangeMap16:

	PHP

	SEP #$20

	PHB

	PHY

	LDA #$00

	PHA

	PLB

	REP #$30

	PHX

	LDA $9A

	STA $0C

	LDA $98

	STA $0E

	LDA #$0000

	SEP #$20

	LDA $5B

	STA $09

	LDA $1933

	BEQ SkipShift

	LSR $09

SkipShift:

	LDY $0E

	LDA $09

	AND #$01

	BEQ LeaveXY

	LDA $9B

	STA $00

	LDA $99

	STA $9B

	LDA $00

	STA $99

	LDY $0C

LeaveXY:

	CPY #$0200

	BCS PrematureEnd

	LDA $1933

	ASL A

	TAX

	LDA $BEA8,x

	STA $65

	LDA $BEA9,x

	STA $66

	STZ $67

	LDA $1925

	ASL A

	TAY

	LDA [$65],y

	STA $04

	INY

	LDA [$65],y

	STA $05

	STZ $06

	LDA $9B

	STA $07

	ASL A

	CLC

	ADC $07

	TAY

	LDA [$04],y

	STA $6B

	STA $6E

	INY

	LDA [$04],y

	STA $6C

	STA $6F

	LDA #$7E

	STA $6D

	INC A

	STA $70

	LDA $09

	AND #$01

	BEQ SwitchXY

	LDA $99		

	LSR A

	LDA $9B

	AND #$01

	BRA CurrentXY

SwitchXY:

	LDA $9B

	LSR A

	LDA $99

CurrentXY:

	ROL A

	ASL A

	ASL A

	ORA #$20

	STA $04

	CPX #$0000

	BEQ NoAdd

	CLC

	ADC #$10

	STA $04

NoAdd:

	LDA $98

	AND #$F0

	CLC

	ASL A

	ROL A

	STA $05

	ROL A

	AND #$03

	ORA $04

	STA $06

	LDA $9A

	AND #$F0

	REP 3 : LSR A

	STA $04

	LDA $05

	AND #$C0

	ORA $04

	STA $07

	REP #$20

	LDA $09

	AND #$0001

	BNE LayerSwitch

	LDA $1A

	SEC

	SBC #$0080

	TAX

	LDY $1C

	LDA $1933

	BEQ CurrentLayer

	LDX $1E

	LDA $20

	SEC

	SBC #$0080

	TAY

	BRA CurrentLayer

LayerSwitch: 

	LDX $1A

	LDA $1C

	SEC

	SBC #$0080

	TAY

	LDA $1933

	BEQ CurrentLayer

	LDA $1E

	SEC

	SBC #$0080

	TAX

	LDY $20

CurrentLayer:

	STX $08

	STY $0A

	LDA $98

	AND #$01F0

	STA $04

	LDA $9A

	REP 4 : LSR A

	AND #$000F

	ORA $04

	TAY

	PLA

	SEP #$20

	STA [$6B],y

	XBA

	STA [$6E],y

	XBA

	REP #$20

	ASL A

	TAY

	PHK

	PER $0006

	PEA $804C

	JML $00C0FB

	PLY

	PLB

	PLP

	RTS