.rtmodel version,"1"
			.rtmodel core,"6502"

			.extern _Vfp
			.extern _Vsp
			.extern _Zp
	
K_NONE:		.equ	0
K_UP		.equ	1
K_DOWN		.equ	2
K_LEFT		.equ	3
K_RIGHT		.equ	4
K_CTRL_R	.equ	5
K_CTRL_S	.equ	6
K_CTRL_L	.equ	7	

			
__internal_read_kb:
IO_DATAOUT$:.equ	0xC000
IO_DATAIN$:	.equ	0xC010
IO_KB_CTRL_LOW$:	.equ	0xC05E
IO_KB_CTRL_HI$:		.equ	0xC05F

			lda		IO_KB_CTRL_HI$
			lda		IO_DATAIN$
			ror		a
			bcc		NoCtrl$
			lda		#0x04
			sta		IO_DATAOUT$
			lda		IO_DATAIN$
			ror		a
			ror		a
			ror		a
			lda		#K_CTRL_R
			bcs		Return$
			lda		#0x02
			sta		IO_DATAOUT$
			lda		IO_DATAIN$
			ror		a
			ror		a
			ror		a
			ror		a
			ror		a
			lda		#K_CTRL_S
			bcs		Return$
			lda		#0x40
			sta		IO_DATAOUT$
			lda		IO_DATAIN$
			ror		a
			ror		a
			ror		a
			ror		a
			ror		a
			lda		#K_CTRL_L
			bcs		Return$			
NoCtrl$:	
			lda		IO_KB_CTRL_LOW$
			ldy		#3
NextKey$:	lda		_rkb_key_inp,y
			sta		IO_DATAOUT$
			lda		IO_DATAIN$
			ror		a
			lda		_rkb_key_ret,y
			bcs		Return$
			dey
			bpl		NextKey$

			lda		#K_NONE
Return$:
			rts
			
_rkb_key_ret:
			.byte	K_LEFT
			.byte	K_RIGHT
			.byte	K_DOWN
			.byte	K_UP

_rkb_key_inp:
			.byte	0x08
			.byte	0x10
			.byte	0x20
			.byte	0x40		
			
;;; Declaration of public symbols
			.public __internal_read_kb