enum
{
	EMISCR=		0x3CC,		/* control sync polarity */
	EMISCW=		0x3C2,
	EFCW=		0x3DA,		/* feature control */
	EFCR=		0x3CA,
	GRX=		0x3CE,		/* index to graphics registers */
	GR=		0x3CF,		/* graphics registers */
	 Grms=		 0x04,		/*  read map select register */
	SRX=		0x3C4,		/* index to sequence registers */
	SR=		0x3C5,		/* sequence registers */
	 Smmask=	 0x02,		/*  map mask */
	CRX=		0x3D4,		/* index to crt registers */
	CR=		0x3D5,		/* crt registers */
	 Cvre=		 0x11,		/*  vertical retrace end */
	ARW=		0x3C0,		/* attribute registers (writing) */
	ARR=		0x3C1,		/* attribute registers (reading) */
	CMRX=		0x3C7,		/* color map read index */
	CMWX=		0x3C8,		/* color map write index */
	CM=		0x3C9,		/* color map data reg */
};

#define SCREENMEM	(0xA0000 | KZERO)
#define CGASCREEN	((uchar*)(0xB8000 | KZERO))
#define	CGAWIDTH	160
#define	CGAHEIGHT	24

extern	void setscreen(int, int, int);
extern	struct GBitmap	gscreen;