/*
 * 86Box	A hypervisor and IBM PC system emulator that specializes in
 *		running old operating systems and software designed for IBM
 *		PC systems and compatibles from 1981 through fairly recent
 *		system designs based on the PCI bus.
 *
 *		This file is part of the 86Box distribution.
 *
 *		Hercules InColor emulation.
 *
 * Version:	@(#)vid_incolor.c	1.0.14	2019/02/08
 *
 * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
 *		Miran Grca, <mgrca8@gmail.com>
 *
 *		Copyright 2008-2018 Sarah Walker.
 *		Copyright 2016-2018 Miran Grca.
 */
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include "../86box.h"
#include "../io.h"
#include "../timer.h"
#include "../lpt.h"
#include "../pit.h"
#include "../mem.h"
#include "../rom.h"
#include "../device.h"
#include "video.h"
#include "vid_incolor.h"


/* extended CRTC registers */
#define INCOLOR_CRTC_XMODE   20 /* xMode register */
#define INCOLOR_CRTC_UNDER   21	/* Underline */
#define INCOLOR_CRTC_OVER    22 /* Overstrike */
#define INCOLOR_CRTC_EXCEPT  23 /* Exception */
#define INCOLOR_CRTC_MASK    24 /* Plane display mask & write mask */
#define INCOLOR_CRTC_RWCTRL  25 /* Read/write control */
#define INCOLOR_CRTC_RWCOL   26 /* Read/write colour */
#define INCOLOR_CRTC_PROTECT 27 /* Latch protect */
#define INCOLOR_CRTC_PALETTE 28 /* Palette */

/* character width */
#define INCOLOR_CW    ((dev->crtc[INCOLOR_CRTC_XMODE] & INCOLOR_XMODE_90COL) ? 8 : 9)

/* mode control register */
#define INCOLOR_CTRL_GRAPH   0x02
#define INCOLOR_CTRL_ENABLE  0x08
#define INCOLOR_CTRL_BLINK   0x20
#define INCOLOR_CTRL_PAGE1   0x80

/* CRTC status register */
#define INCOLOR_STATUS_HSYNC 0x01		/* horizontal sync */
#define INCOLOR_STATUS_LIGHT 0x02
#define INCOLOR_STATUS_VIDEO 0x08
#define INCOLOR_STATUS_ID    0x50		/* Card identification */
#define INCOLOR_STATUS_VSYNC 0x80		/* -vertical sync */

/* configuration switch register */
#define INCOLOR_CTRL2_GRAPH 0x01
#define INCOLOR_CTRL2_PAGE1 0x02

/* extended mode register */
#define INCOLOR_XMODE_RAMFONT 0x01
#define INCOLOR_XMODE_90COL   0x02


/* Read/write control */
#define INCOLOR_RWCTRL_WRMODE   0x30
#define INCOLOR_RWCTRL_POLARITY 0x40

/* exception register */
#define INCOLOR_EXCEPT_CURSOR  0x0F		/* Cursor colour */
#define INCOLOR_EXCEPT_PALETTE 0x10		/* Enable palette register */
#define INCOLOR_EXCEPT_ALTATTR 0x20		/* Use alternate attributes */



/* Default palette */
static const uint8_t defpal[16] = {
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
    0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F
};

/* Mapping of inks to RGB */
static const uint8_t init_rgb[64][3] = {
				/* rgbRGB */
    { 0x00, 0x00, 0x00 },	/* 000000 */
    { 0x00, 0x00, 0xaa },	/* 000001 */
    { 0x00, 0xaa, 0x00 },	/* 000010 */
    { 0x00, 0xaa, 0xaa },	/* 000011 */
    { 0xaa, 0x00, 0x00 },	/* 000100 */
    { 0xaa, 0x00, 0xaa },	/* 000101 */
    { 0xaa, 0xaa, 0x00 },	/* 000110 */
    { 0xaa, 0xaa, 0xaa },	/* 000111 */
    { 0x00, 0x00, 0x55 },	/* 001000 */
    { 0x00, 0x00, 0xff },	/* 001001 */
    { 0x00, 0xaa, 0x55 },	/* 001010 */
    { 0x00, 0xaa, 0xff },	/* 001011 */
    { 0xaa, 0x00, 0x55 },	/* 001100 */
    { 0xaa, 0x00, 0xff },	/* 001101 */
    { 0xaa, 0xaa, 0x55 },	/* 001110 */
    { 0xaa, 0xaa, 0xff },	/* 001111 */
    { 0x00, 0x55, 0x00 },	/* 010000 */
    { 0x00, 0x55, 0xaa },	/* 010001 */
    { 0x00, 0xff, 0x00 },	/* 010010 */
    { 0x00, 0xff, 0xaa },	/* 010011 */
    { 0xaa, 0x55, 0x00 },	/* 010100 */
    { 0xaa, 0x55, 0xaa },	/* 010101 */
    { 0xaa, 0xff, 0x00 },	/* 010110 */
    { 0xaa, 0xff, 0xaa },	/* 010111 */
    { 0x00, 0x55, 0x55 },	/* 011000 */
    { 0x00, 0x55, 0xff },	/* 011001 */
    { 0x00, 0xff, 0x55 },	/* 011010 */
    { 0x00, 0xff, 0xff },	/* 011011 */
    { 0xaa, 0x55, 0x55 },	/* 011100 */
    { 0xaa, 0x55, 0xff },	/* 011101 */
    { 0xaa, 0xff, 0x55 },	/* 011110 */
    { 0xaa, 0xff, 0xff },	/* 011111 */
    { 0x55, 0x00, 0x00 },	/* 100000 */
    { 0x55, 0x00, 0xaa },	/* 100001 */
    { 0x55, 0xaa, 0x00 },	/* 100010 */
    { 0x55, 0xaa, 0xaa },	/* 100011 */
    { 0xff, 0x00, 0x00 },	/* 100100 */
    { 0xff, 0x00, 0xaa },	/* 100101 */
    { 0xff, 0xaa, 0x00 },	/* 100110 */
    { 0xff, 0xaa, 0xaa },	/* 100111 */
    { 0x55, 0x00, 0x55 },	/* 101000 */
    { 0x55, 0x00, 0xff },	/* 101001 */
    { 0x55, 0xaa, 0x55 },	/* 101010 */
    { 0x55, 0xaa, 0xff },	/* 101011 */
    { 0xff, 0x00, 0x55 },	/* 101100 */
    { 0xff, 0x00, 0xff },	/* 101101 */
    { 0xff, 0xaa, 0x55 },	/* 101110 */
    { 0xff, 0xaa, 0xff },	/* 101111 */
    { 0x55, 0x55, 0x00 },	/* 110000 */
    { 0x55, 0x55, 0xaa },	/* 110001 */
    { 0x55, 0xff, 0x00 },	/* 110010 */
    { 0x55, 0xff, 0xaa },	/* 110011 */
    { 0xff, 0x55, 0x00 },	/* 110100 */
    { 0xff, 0x55, 0xaa },	/* 110101 */
    { 0xff, 0xff, 0x00 },	/* 110110 */
    { 0xff, 0xff, 0xaa },	/* 110111 */
    { 0x55, 0x55, 0x55 },	/* 111000 */
    { 0x55, 0x55, 0xff },	/* 111001 */
    { 0x55, 0xff, 0x55 },	/* 111010 */
    { 0x55, 0xff, 0xff },	/* 111011 */
    { 0xff, 0x55, 0x55 },	/* 111100 */
    { 0xff, 0x55, 0xff },	/* 111101 */
    { 0xff, 0xff, 0x55 },	/* 111110 */
    { 0xff, 0xff, 0xff },	/* 111111 */
};


typedef struct {
    mem_mapping_t	mapping;

    uint8_t	crtc[32];
    int		crtcreg;

    uint8_t	ctrl, ctrl2, stat;

    uint64_t	dispontime, dispofftime;
    pc_timer_t	timer;

    int		firstline, lastline;

    int		linepos, displine;
    int		vc, sc;
    uint16_t	ma, maback;
    int		con, coff, cursoron;
    int		dispon, blink;
    int	vsynctime;
    int		vadj;

    uint8_t	palette[16];	/* EGA-style 16 -> 64 palette registers */
    uint8_t	palette_idx;	/* Palette write index */
    uint8_t	latch[4];	/* Memory read/write latches */

    uint32_t	rgb[64];

    uint8_t	*vram;
} incolor_t;

static video_timings_t timing_incolor = {VIDEO_ISA, 8, 16, 32,   8, 16, 32};


static void
recalc_timings(incolor_t *dev)
{
    double disptime;
    double _dispontime, _dispofftime;

    disptime = dev->crtc[0] + 1;
    _dispontime  = dev->crtc[1];
    _dispofftime = disptime - _dispontime;
    _dispontime  *= HERCCONST;
    _dispofftime *= HERCCONST;

    dev->dispontime  = (uint64_t)(_dispontime);
    dev->dispofftime = (uint64_t)(_dispofftime);
}


static void
incolor_out(uint16_t port, uint8_t val, void *priv)
{
    incolor_t *dev = (incolor_t *)priv;
    uint8_t old;

    switch (port) {
	case 0x3b0:
	case 0x3b2:
	case 0x3b4:
	case 0x3b6:
		dev->crtcreg = val & 31;
		return;

	case 0x3b1: case 0x3b3: case 0x3b5: case 0x3b7:
		if (dev->crtcreg > 28) return;
		/* Palette load register */
		if (dev->crtcreg == INCOLOR_CRTC_PALETTE) {
			dev->palette[dev->palette_idx % 16] = val;
			++dev->palette_idx;
		} 
		old = dev->crtc[dev->crtcreg];
		dev->crtc[dev->crtcreg] = val;

		if (dev->crtc[10] == 6 && dev->crtc[11] == 7) {
			/*Fix for Generic Turbo XT BIOS,
			 * which sets up cursor registers wrong*/
			dev->crtc[10] = 0xb;
			dev->crtc[11] = 0xc;
		}
		if (old ^ val)
			recalc_timings(dev);
		return;

	case 0x3b8:
		old = dev->ctrl;
		dev->ctrl = val;
		if (old ^ val)
			recalc_timings(dev);
		return;

	case 0x3bf:
		dev->ctrl2 = val;
		if (val & 2)
			mem_mapping_set_addr(&dev->mapping, 0xb0000, 0x10000);
		else
			mem_mapping_set_addr(&dev->mapping, 0xb0000, 0x08000);
		return;
    }
}


static uint8_t
incolor_in(uint16_t port, void *priv)
{
    incolor_t *dev = (incolor_t *)priv;
    uint8_t ret = 0xff;

    switch (port) {
	case 0x3b0:
	case 0x3b2:
	case 0x3b4:
	case 0x3b6:
		ret = dev->crtcreg;
		break;

	case 0x3b1:
	case 0x3b3:
	case 0x3b5:
	case 0x3b7:
		if (dev->crtcreg > 28) break;

		dev->palette_idx = 0;	/* Read resets the palette index */
		ret = dev->crtc[dev->crtcreg];
		break;

	case 0x3ba:
		/* 0x50: InColor card identity */
		ret = (dev->stat & 0xf) | ((dev->stat & 8) << 4) | 0x50;
		break;

	default:
		break;
    }

    return ret;
}


static void
incolor_write(uint32_t addr, uint8_t val, void *priv)
{
    incolor_t *dev = (incolor_t *)priv;
    unsigned char wmask = dev->crtc[INCOLOR_CRTC_MASK];
    unsigned char wmode = dev->crtc[INCOLOR_CRTC_RWCTRL] & INCOLOR_RWCTRL_WRMODE;
    unsigned char fg = dev->crtc[INCOLOR_CRTC_RWCOL] & 0x0F;
    unsigned char bg = (dev->crtc[INCOLOR_CRTC_RWCOL] >> 4)&0x0F;
    unsigned char w = 0;
    unsigned char vmask;	/* Mask of bit within byte */
    unsigned char pmask;	/* Mask of plane within colour value */
    unsigned char latch;
    int plane;

    addr &= 0xffff;

    /* In text mode, writes to the bottom 16k always touch all 4 planes */
    if (!(dev->ctrl & INCOLOR_CTRL_GRAPH) && addr < 0x4000) {
	dev->vram[addr] = val;
	return;
    }

    /* There are four write modes:
     * 0: 1 => foreground,    0 => background
     * 1: 1 => foreground,    0 => source latch
     * 2: 1 => source latch,  0 => background
     * 3: 1 => source latch,  0 => ~source latch 
     */
    pmask = 1;
    for (plane = 0; plane < 4; pmask <<= 1, wmask >>= 1, addr += 0x10000, plane++) {
	if (wmask & 0x10) /* Ignore writes to selected plane */
	{
		continue;
	}
	latch = dev->latch[plane];
	for (vmask = 0x80; vmask != 0; vmask >>= 1) {
		switch (wmode) {
			case 0x00:
				if (val & vmask) w = (fg & pmask);
				else		 w = (bg & pmask);
				break;

			case 0x10:
				if (val & vmask) w = (fg    & pmask);
				else		 w = (latch & vmask);
				break;

			case 0x20:
				if (val & vmask) w = (latch & vmask);
				else		 w = (bg    & pmask);
				break;

			case 0x30:
				if (val & vmask) w = (latch    & vmask);
				else		 w = ((~latch) & vmask);
				break;
		}

		/* w is nonzero to write a 1, zero to write a 0 */
		if (w)	dev->vram[addr] |= vmask;
		else	dev->vram[addr] &= ~vmask; 	
	}
    }
}


static uint8_t
incolor_read(uint32_t addr, void *priv)
{
    incolor_t *dev = (incolor_t *)priv;
    unsigned plane;
    unsigned char lp = dev->crtc[INCOLOR_CRTC_PROTECT];
    unsigned char value = 0;
    unsigned char dc;	/* "don't care" register */
    unsigned char bg;	/* background colour */
    unsigned char fg;
    unsigned char mask, pmask;

    addr &= 0xffff;

    /* Read the four planes into latches */
    for (plane = 0; plane < 4; plane++, addr += 0x10000) {
	dev->latch[plane] &= lp;
	dev->latch[plane] |= (dev->vram[addr] & ~lp);
    }
    addr &= 0xffff;

    /* In text mode, reads from the bottom 16k assume all planes have
     * the same contents */
    if (!(dev->ctrl & INCOLOR_CTRL_GRAPH) && addr < 0x4000) {
	return dev->latch[0];
    }

    /* For each pixel, work out if its colour matches the background */
    for (mask = 0x80; mask != 0; mask >>= 1) {
	fg = 0;
	dc = dev->crtc[INCOLOR_CRTC_RWCTRL] & 0x0F;
	bg = (dev->crtc[INCOLOR_CRTC_RWCOL] >> 4) & 0x0F;
	for (plane = 0, pmask = 1; plane < 4; plane++, pmask <<= 1) {
		if (dc & pmask) {
			fg |= (bg & pmask); 
		} else if (dev->latch[plane] & mask) {
			fg |= pmask;
		}
	}		
	if (bg == fg) value |= mask;
    }	

    if (dev->crtc[INCOLOR_CRTC_RWCTRL] & INCOLOR_RWCTRL_POLARITY) 
	value = ~value;

    return value;
}


static void
draw_char_rom(incolor_t *dev, int x, uint8_t chr, uint8_t attr)
{
	int		 i;
	int		 elg, blk;
	unsigned	    ull;
	unsigned	    val;
	unsigned	    ifg, ibg;
	const unsigned char *fnt;
	uint32_t	    fg, bg;
	int		    cw = INCOLOR_CW;

	blk = 0;
	if (dev->ctrl & INCOLOR_CTRL_BLINK) 
	{
		if (attr & 0x80) 
		{
			blk = (dev->blink & 16);
		}
		attr &= 0x7f;
	}

	if (dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_ALTATTR) 
	{
		/* MDA-compatible attributes */
		ibg = 0;
		ifg = 7;
		if ((attr & 0x77) == 0x70)	 /* Invert */
		{
			ifg = 0;
			ibg = 7;
		}	
		if (attr & 8) 
		{
			ifg |= 8;	/* High intensity FG */
		}
		if (attr & 0x80) 
		{
			ibg |= 8;	/* High intensity BG */
		}
		if ((attr & 0x77) == 0)	/* Blank */
		{
			ifg = ibg;
		}
		ull = ((attr & 0x07) == 1) ? 13 : 0xffff;
	} 
	else 
	{
		/* CGA-compatible attributes */
		ull = 0xffff;
		ifg = attr & 0x0F;
		ibg = (attr >> 4) & 0x0F;
	}
	if (dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_PALETTE) 
	{
		fg = dev->rgb[dev->palette[ifg]];
		bg = dev->rgb[dev->palette[ibg]];
	} 
	else 
	{
		fg = dev->rgb[defpal[ifg]];
		bg = dev->rgb[defpal[ibg]];
	}

	/* ELG set to stretch 8px character to 9px */
	if (dev->crtc[INCOLOR_CRTC_XMODE] & INCOLOR_XMODE_90COL) 
	{
		elg = 0;
	} 
	else 
	{
		elg = ((chr >= 0xc0) && (chr <= 0xdf));
	}

	fnt = &(fontdatm[chr][dev->sc]);

	if (blk)
	{
		val = 0x000;	/* Blinking, draw all background */
	}
	else if (dev->sc == ull) 
	{
		val = 0x1ff;	/* Underscore, draw all foreground */
	}
	else 
	{
		val = fnt[0] << 1;
	
		if (elg) 
		{
			val |= (val >> 1) & 1;
		}
	}
	for (i = 0; i < cw; i++) 
	{
		buffer32->line[dev->displine][x * cw + i] = (val & 0x100) ? fg : bg;
		val = val << 1;
	}
}


static void
draw_char_ram4(incolor_t *dev, int x, uint8_t chr, uint8_t attr)
{
	int		 i;
	int		 elg, blk;
	unsigned	    ull;
	unsigned	    val[4];
	unsigned	    ifg, ibg, cfg, pmask, plane;
	const unsigned char *fnt;
	uint32_t	    fg;
	int		    cw = INCOLOR_CW;
	int		 blink   = dev->ctrl & INCOLOR_CTRL_BLINK;
	int		 altattr = dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_ALTATTR;
	int		 palette = dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_PALETTE;

	blk = 0;
	if (blink)
	{
		if (attr & 0x80) 
		{
			blk = (dev->blink & 16);
		}
		attr &= 0x7f;
	}

	if (altattr)
	{
		/* MDA-compatible attributes */
		ibg = 0;
		ifg = 7;
		if ((attr & 0x77) == 0x70)	 /* Invert */
		{
			ifg = 0;
			ibg = 7;
		}	
		if (attr & 8) 
		{
			ifg |= 8;	/* High intensity FG */
		}
		if (attr & 0x80) 
		{
			ibg |= 8;	/* High intensity BG */
		}
		if ((attr & 0x77) == 0)	/* Blank */
		{
			ifg = ibg;
		}
		ull = ((attr & 0x07) == 1) ? 13 : 0xffff;
	} 
	else 
	{
		/* CGA-compatible attributes */
		ull = 0xffff;
		ifg = attr & 0x0F;
		ibg = (attr >> 4) & 0x0F;
	}
	if (dev->crtc[INCOLOR_CRTC_XMODE] & INCOLOR_XMODE_90COL) 
	{
		elg = 0;
	} 
	else 
	{
		elg = ((chr >= 0xc0) && (chr <= 0xdf));
	}
	fnt = dev->vram + 0x4000 + 16 * chr + dev->sc;

	if (blk)
	{
		/* Blinking, draw all background */
		val[0] = val[1] = val[2] = val[3] = 0x000;	
	}
	else if (dev->sc == ull) 
	{
		/* Underscore, draw all foreground */
		val[0] = val[1] = val[2] = val[3] = 0x1ff;
	}
	else 
	{
		val[0] = fnt[0x00000] << 1;
		val[1] = fnt[0x10000] << 1;
		val[2] = fnt[0x20000] << 1;
		val[3] = fnt[0x30000] << 1;
	
		if (elg) 
		{
			val[0] |= (val[0] >> 1) & 1;
			val[1] |= (val[1] >> 1) & 1;
			val[2] |= (val[2] >> 1) & 1;
			val[3] |= (val[3] >> 1) & 1;
		}
	}
	for (i = 0; i < cw; i++) 
	{
		/* Generate pixel colour */
		cfg = 0;
		pmask = 1;
		for (plane = 0; plane < 4; plane++, pmask = pmask << 1)
		{
			if (val[plane] & 0x100) cfg |= (ifg & pmask);
			else			cfg |= (ibg & pmask);
		}
		/* cfg = colour of foreground pixels */
		if (altattr && (attr & 0x77) == 0) cfg = ibg; /* 'blank' attribute */
		if (palette)
		{
			fg = dev->rgb[dev->palette[cfg]];
		} 
		else 
		{
			fg = dev->rgb[defpal[cfg]];
		}
		
		buffer32->line[dev->displine][x * cw + i] = fg;
		val[0] = val[0] << 1;
		val[1] = val[1] << 1;
		val[2] = val[2] << 1;
		val[3] = val[3] << 1;
	}
}


static void
draw_char_ram48(incolor_t *dev, int x, uint8_t chr, uint8_t attr)
{
	int		 i;
	int		 elg, blk, ul, ol, bld;
	unsigned	    ull, oll, ulc = 0, olc = 0;
	unsigned	    val[4];
	unsigned	    ifg = 0, ibg, cfg, pmask, plane;
	const unsigned char *fnt;
	uint32_t	    fg;
	int		    cw = INCOLOR_CW;
	int		 blink   = dev->ctrl & INCOLOR_CTRL_BLINK;
	int		 altattr = dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_ALTATTR;
	int		 palette = dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_PALETTE;
	int		    font = (attr & 0x0F);

	if (font >= 12) font &= 7;

	blk = 0;
	if (blink && altattr)
	{
		if (attr & 0x40) 
		{
			blk = (dev->blink & 16);
		}
		attr &= 0x7f;
	}
	if (altattr) 
	{
		/* MDA-compatible attributes */
		if (blink) 
		{
			ibg = (attr & 0x80) ? 8 : 0;
			bld = 0;
			ol  = (attr & 0x20) ? 1 : 0;
			ul  = (attr & 0x10) ? 1 : 0;
		} 
		else 
		{
			bld = (attr & 0x80) ? 1 : 0;
			ibg = (attr & 0x40) ? 0x0F : 0;
			ol  = (attr & 0x20) ? 1 : 0;
			ul  = (attr & 0x10) ? 1 : 0;
		}
	} 
	else 
	{
		/* CGA-compatible attributes */
		ibg = 0;
		ifg = (attr >> 4) & 0x0F;
		ol  = 0;
		ul  = 0;
		bld = 0;
	}
	if (ul) 
	{ 
		ull = dev->crtc[INCOLOR_CRTC_UNDER] & 0x0F;
		ulc = (dev->crtc[INCOLOR_CRTC_UNDER] >> 4) & 0x0F;
		if (ulc == 0) ulc = 7;
	} 
	else 
	{
		ull = 0xFFFF;
	}
	if (ol) 
	{ 
		oll = dev->crtc[INCOLOR_CRTC_OVER] & 0x0F;
		olc = (dev->crtc[INCOLOR_CRTC_OVER] >> 4) & 0x0F;
		if (olc == 0) olc = 7;
	} 
	else 
	{
		oll = 0xFFFF;
	}

	if (dev->crtc[INCOLOR_CRTC_XMODE] & INCOLOR_XMODE_90COL) 
	{
		elg = 0;
	} 
	else 
	{
		elg = ((chr >= 0xc0) && (chr <= 0xdf));
	}
	fnt = dev->vram + 0x4000 + 16 * chr + 4096 * font + dev->sc;

	if (blk)
	{
		/* Blinking, draw all background */
		val[0] = val[1] = val[2] = val[3] = 0x000;	
	}
	else if (dev->sc == ull) 
	{
		/* Underscore, draw all foreground */
		val[0] = val[1] = val[2] = val[3] = 0x1ff;
	}
	else 
	{
		val[0] = fnt[0x00000] << 1;
		val[1] = fnt[0x10000] << 1;
		val[2] = fnt[0x20000] << 1;
		val[3] = fnt[0x30000] << 1;
	
		if (elg) 
		{
			val[0] |= (val[0] >> 1) & 1;
			val[1] |= (val[1] >> 1) & 1;
			val[2] |= (val[2] >> 1) & 1;
			val[3] |= (val[3] >> 1) & 1;
		}
		if (bld) 
		{
			val[0] |= (val[0] >> 1);
			val[1] |= (val[1] >> 1);
			val[2] |= (val[2] >> 1);
			val[3] |= (val[3] >> 1);
		}
	}
	for (i = 0; i < cw; i++) 
	{
		/* Generate pixel colour */
		cfg = 0;
		pmask = 1;
		if (dev->sc == oll)
		{
			cfg = olc ^ ibg;	/* Strikethrough */
		}
		else if (dev->sc == ull)
		{
			cfg = ulc ^ ibg;	/* Underline */
		}
		else
		{
			for (plane = 0; plane < 4; plane++, pmask = pmask << 1)
			{
				if (val[plane] & 0x100)
				{
					if (altattr)	cfg |= ((~ibg) & pmask);
					else		cfg |= ((~ifg) & pmask);
				}
				else if (altattr)	cfg |= (ibg & pmask);
			}
		}
		if (palette)
		{
			fg = dev->rgb[dev->palette[cfg]];
		} 
		else 
		{
			fg = dev->rgb[defpal[cfg]];
		}
		
		buffer32->line[dev->displine][x * cw + i] = fg;
		val[0] = val[0] << 1;
		val[1] = val[1] << 1;
		val[2] = val[2] << 1;
		val[3] = val[3] << 1;
	}
}


static void
text_line(incolor_t *dev, uint16_t ca)
{
    int drawcursor;
    int x, c;
    uint8_t chr, attr;
    uint32_t col;

    for (x = 0; x < dev->crtc[1]; x++) {
	if (dev->ctrl & 8) {
		chr  = dev->vram[(dev->ma << 1) & 0xfff];
		attr = dev->vram[((dev->ma << 1) + 1) & 0xfff];
	} else
		chr = attr = 0;

	drawcursor = ((dev->ma == ca) && dev->con && dev->cursoron);

	switch (dev->crtc[INCOLOR_CRTC_XMODE] & 5) {
		case 0:
		case 4:	/* ROM font */
			draw_char_rom(dev, x, chr, attr);
			break;

		case 1: /* 4k RAMfont */
			draw_char_ram4(dev, x, chr, attr);
			break;

		case 5: /* 48k RAMfont */
			draw_char_ram48(dev, x, chr, attr);
			break;
	}
	++dev->ma;

	if (drawcursor) {
		int cw = INCOLOR_CW;
		uint8_t ink = dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_CURSOR;
		if (ink == 0) ink = (attr & 0x08) | 7;

		/* In MDA-compatible mode, cursor brightness comes from 
		 * background */
		if (dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_ALTATTR) 
		{
			ink = (attr & 0x08) | (ink & 7);
		}
		if (dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_PALETTE) 
		{
			col = dev->rgb[dev->palette[ink]];
		} 
		else 
		{
			col = dev->rgb[defpal[ink]];
		}
		for (c = 0; c < cw; c++)
		{
			buffer32->line[dev->displine][x * cw + c] = col;
		}
	}
    }
}


static void
graphics_line(incolor_t *dev)
{
    uint8_t mask;
    uint16_t ca;
    int x, c, plane, col;
    uint8_t ink;
    uint16_t val[4];

    /* Graphics mode. */
    ca = (dev->sc & 3) * 0x2000;
    if ((dev->ctrl & INCOLOR_CTRL_PAGE1) && (dev->ctrl2 & INCOLOR_CTRL2_PAGE1))
	ca += 0x8000;

    for (x = 0; x < dev->crtc[1]; x++) {
	mask = dev->crtc[INCOLOR_CRTC_MASK];	/* Planes to display */
	for (plane = 0; plane < 4; plane++, mask = mask >> 1)
	{
		if (dev->ctrl & 8) {
			if (mask & 1) 
				val[plane] = (dev->vram[((dev->ma << 1) & 0x1fff) + ca + 0x10000 * plane] << 8) | 
					      dev->vram[((dev->ma << 1) & 0x1fff) + ca + 0x10000 * plane + 1];
			else	val[plane] = 0;
		} else
			val[plane] = 0;
	}
	dev->ma++;

	for (c = 0; c < 16; c++)
	{
		ink = 0;
		for (plane = 0; plane < 4; plane++)
		{
			ink = ink >> 1;
			if (val[plane] & 0x8000) ink |= 8;
			val[plane] = val[plane] << 1;
		}
		/* Is palette in use? */
		if (dev->crtc[INCOLOR_CRTC_EXCEPT] & INCOLOR_EXCEPT_PALETTE)
			col = dev->palette[ink];
		else	col = defpal[ink];

		buffer32->line[dev->displine][(x << 4) + c] = dev->rgb[col];
	}
    }
}


static void
incolor_poll(void *priv)
{
    incolor_t *dev = (incolor_t *)priv;
    uint16_t ca = (dev->crtc[15] | (dev->crtc[14] << 8)) & 0x3fff;
    int x;
    int oldvc;
    int oldsc;

    if (! dev->linepos) {
	timer_advance_u64(&dev->timer, dev->dispofftime);
	dev->stat |= 1;
	dev->linepos = 1;
	oldsc = dev->sc;
	if ((dev->crtc[8] & 3) == 3) 
		dev->sc = (dev->sc << 1) & 7;

	if (dev->dispon) {
		if (dev->displine < dev->firstline) {
			dev->firstline = dev->displine;
			video_wait_for_buffer();
		}
		dev->lastline = dev->displine;
		if ((dev->ctrl & INCOLOR_CTRL_GRAPH) && (dev->ctrl2 & INCOLOR_CTRL2_GRAPH))
				graphics_line(dev);
			else
				text_line(dev, ca);
	}
	dev->sc = oldsc;
	if (dev->vc == dev->crtc[7] && !dev->sc)
		dev->stat |= 8;
	dev->displine++;
	if (dev->displine >= 500) 
		dev->displine = 0;
    } else {
	timer_advance_u64(&dev->timer, dev->dispontime);
	if (dev->dispon) 
		dev->stat &= ~1;
	dev->linepos = 0;
	if (dev->vsynctime) {
		dev->vsynctime--;
		if (! dev->vsynctime)
			dev->stat &= ~8;
	}

	if (dev->sc == (dev->crtc[11] & 31) || ((dev->crtc[8] & 3) == 3 && dev->sc == ((dev->crtc[11] & 31) >> 1))) { 
		dev->con = 0; 
		dev->coff = 1; 
	}

	if (dev->vadj) {
		dev->sc++;
		dev->sc &= 31;
		dev->ma = dev->maback;
		dev->vadj--;
		if (! dev->vadj) {
			dev->dispon = 1;
			dev->ma = dev->maback = (dev->crtc[13] | (dev->crtc[12] << 8)) & 0x3fff;
			dev->sc = 0;
		}
	} else if (dev->sc == dev->crtc[9] || ((dev->crtc[8] & 3) == 3 && dev->sc == (dev->crtc[9] >> 1))) {
		dev->maback = dev->ma;
		dev->sc = 0;
		oldvc = dev->vc;
		dev->vc++;
		dev->vc &= 127;
		if (dev->vc == dev->crtc[6]) 
			dev->dispon = 0;
		if (oldvc == dev->crtc[4]) {
			dev->vc = 0;
			dev->vadj = dev->crtc[5];
			if (!dev->vadj) dev->dispon=1;
			if (!dev->vadj) dev->ma = dev->maback = (dev->crtc[13] | (dev->crtc[12] << 8)) & 0x3fff;
			if ((dev->crtc[10] & 0x60) == 0x20) dev->cursoron = 0;
			else				     dev->cursoron = dev->blink & 16;
		}

		if (dev->vc == dev->crtc[7]) {
			dev->dispon = 0;
			dev->displine = 0;
			dev->vsynctime = 16;
			if (dev->crtc[7]) {
				if ((dev->ctrl & INCOLOR_CTRL_GRAPH) && (dev->ctrl2 & INCOLOR_CTRL2_GRAPH)) 
					x = dev->crtc[1] << 4;
				else
				       x = dev->crtc[1] * 9;
				dev->lastline++;
				if ((dev->ctrl & 8) &&
				   ((x != xsize) || ((dev->lastline - dev->firstline) != ysize) || video_force_resize_get())) {
					xsize = x;
					ysize = dev->lastline - dev->firstline;
					if (xsize < 64) xsize = 656;
					if (ysize < 32) ysize = 200;
					set_screen_size(xsize, ysize);

					if (video_force_resize_get())
						video_force_resize_set(0);
				}
				video_blit_memtoscreen(0, dev->firstline, 0, dev->lastline - dev->firstline, xsize, dev->lastline - dev->firstline);
				frames++;
				if ((dev->ctrl & INCOLOR_CTRL_GRAPH) && (dev->ctrl2 & INCOLOR_CTRL2_GRAPH)) {
					video_res_x = dev->crtc[1] * 16;
					video_res_y = dev->crtc[6] * 4;
					video_bpp = 1;
				} else {
					video_res_x = dev->crtc[1];
					video_res_y = dev->crtc[6];
					video_bpp = 0;
				}
			}
			dev->firstline = 1000;
			dev->lastline = 0;
			dev->blink++;
		}
	} else {
		dev->sc++;
		dev->sc &= 31;
		dev->ma = dev->maback;
	}

	if ((dev->sc == (dev->crtc[10] & 31) || ((dev->crtc[8] & 3) == 3 && dev->sc == ((dev->crtc[10] & 31) >> 1))))
		dev->con = 1;
    }
}


static void *
incolor_init(const device_t *info)
{
    incolor_t *dev;
    int c;

    dev = (incolor_t *)malloc(sizeof(incolor_t));
    memset(dev, 0x00, sizeof(incolor_t));

    dev->vram = (uint8_t *)malloc(0x40000);	/* 4 planes of 64k */

	timer_add(&dev->timer, incolor_poll, dev, 1);

    mem_mapping_add(&dev->mapping, 0xb0000, 0x08000,
		    incolor_read,NULL,NULL, incolor_write,NULL,NULL,
		    NULL, MEM_MAPPING_EXTERNAL, dev);

    io_sethandler(0x03b0, 16,
		  incolor_in,NULL,NULL, incolor_out,NULL,NULL, dev);

    for (c = 0; c < 64; c++) {
	dev->rgb[c] = makecol32(init_rgb[c][0], init_rgb[c][1], init_rgb[c][2]);
    }

    /* Initialise CRTC regs to safe values */
    dev->crtc[INCOLOR_CRTC_MASK  ] = 0x0F; /* All planes displayed */
    dev->crtc[INCOLOR_CRTC_RWCTRL] = INCOLOR_RWCTRL_POLARITY;
    dev->crtc[INCOLOR_CRTC_RWCOL ] = 0x0F; /* White on black */
    dev->crtc[INCOLOR_CRTC_EXCEPT] = INCOLOR_EXCEPT_ALTATTR;
    for (c = 0; c < 16; c++) 
	dev->palette[c] = defpal[c];
    dev->palette_idx = 0;

    video_inform(VIDEO_FLAG_TYPE_MDA, &timing_incolor);

    /* Force the LPT3 port to be enabled. */
    lpt3_init(0x3BC);

    return dev;
}


static void
incolor_close(void *priv)
{
    incolor_t *dev = (incolor_t *)priv;

    if (!dev)
	return;

    if (dev->vram)
	free(dev->vram);

    free(dev);
}


static void
speed_changed(void *priv)
{
    incolor_t *dev = (incolor_t *)priv;
	
    recalc_timings(dev);
}


const device_t incolor_device = {
    "Hercules InColor",
    DEVICE_ISA,
    0,
    incolor_init, incolor_close, NULL,
    NULL,
    speed_changed,
    NULL,
    NULL
};