Adding upstream version 7.0.6-dfsg.upstream/7.0.6-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2805 insertions, 0 deletions

diff --git a/src/VBox/Devices/Graphics/BIOS/vgabios.c b/src/VBox/Devices/Graphics/BIOS/vgabios.c
new file mode 100644
index 00000000..7c415481
--- /dev/null
+++ b/src/VBox/Devices/Graphics/BIOS/vgabios.c
@@ -0,0 +1,2805 @@
+// ============================================================================================
+/*
+ * vgabios.c
+ */
+// ============================================================================================
+//
+//  Copyright (C) 2001,2002 the LGPL VGABios developers Team
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2 of the License, or (at your option) any later version.
+//
+//  This library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+//
+// ============================================================================================
+//
+//  This VGA Bios is specific to the plex86/bochs Emulated VGA card.
+//  You can NOT drive any physical vga card with it.
+//
+// ============================================================================================
+//
+//  This file contains code ripped from :
+//   - rombios.c of plex86
+//
+//  This VGA Bios contains fonts from :
+//   - fntcol16.zip (c) by Joseph Gil avalable at :
+//      ftp://ftp.simtel.net/pub/simtelnet/msdos/screen/fntcol16.zip
+//     These fonts are public domain
+//
+//  This VGA Bios is based on information taken from :
+//   - Kevin Lawton's vga card emulation for bochs/plex86
+//   - Ralf Brown's interrupts list available at http://www.cs.cmu.edu/afs/cs/user/ralf/pub/WWW/files.html
+//   - Finn Thogersons' VGADOC4b available at http://home.worldonline.dk/~finth/
+//   - Michael Abrash's Graphics Programming Black Book
+//   - Francois Gervais' book "programmation des cartes graphiques cga-ega-vga" edited by sybex
+//   - DOSEMU 1.0.1 source code for several tables values and formulas
+//
+// Thanks for patches, comments and ideas to :
+//   - techt@pikeonline.net
+//
+// ============================================================================================
+
+
+/*
+ * Oracle LGPL Disclaimer: For the avoidance of doubt, except that if any license choice
+ * other than GPL or LGPL is available it will apply instead, Oracle elects to use only
+ * the Lesser General Public License version 2.1 (LGPLv2) at this time for any software where
+ * a choice of LGPL license versions is made available with the language indicating
+ * that LGPLv2 or any later version may be used, or where a choice of which version
+ * of the LGPL is applied is otherwise unspecified.
+ */
+
+#include <inttypes.h>
+#include "vgabios.h"
+
+#ifdef VBE
+#include "vbe.h"
+#endif
+
+#include "inlines.h"
+
+/* Declares */
+extern void vgabios_int10_handler(void);
+#pragma aux vgabios_int10_handler "*";
+
+// Output
+void __cdecl          unimplemented(void);
+void __cdecl          unknown(void);
+
+static uint8_t find_vga_entry();
+
+extern uint8_t readx_byte(uint16_t seg, uint16_t offset);
+
+#ifdef VBE
+extern uint16_t __cdecl vbe_has_vbe_display(void);
+extern void             vbe_init(void);
+#endif
+
+void set_int_vector(uint8_t int_vec, void __far *ptr)
+{
+    void __far * __far *ivt = 0;
+
+    ivt[int_vec] = ptr;
+}
+
+//@todo!!
+#if 0
+
+vgabios_name:
+#ifdef VBOX
+.ascii  "VirtualBox VGA BIOS"
+#else
+.ascii  "Plex86/Bochs VGABios"
+#endif
+.ascii  " "
+.byte   0x00
+
+#ifndef VBOX
+vgabios_version:
+#ifndef VGABIOS_VERS
+.ascii  "current-cvs"
+#else
+.ascii VGABIOS_VERS
+#endif
+.ascii  " "
+
+vgabios_date:
+.ascii  VGABIOS_DATE
+.byte   0x0a,0x0d
+.byte   0x00
+#endif
+
+#ifndef VBOX
+char vgabios_copyright[] = "(C) 2003 the LGPL VGABios developers Team\r\n";
+char vgabios_license[]   = "This VGA/VBE Bios is released under the GNU LGPL\r\n\r\n";
+char vgabios_website[]   = "Please visit :\r\n" \
+                           " . http://www.plex86.org\r\n" \
+                           " . http://bochs.sourceforge.net\r\n" \
+                           " . http://www.nongnu.org/vgabios\r\n\r\n"
+#endif
+
+#endif
+
+extern void set_mode(int mode);
+#pragma aux set_mode =  \
+    "xor    ah, ah"     \
+    "int    10h"        \
+    parm [ax];
+
+char msg_vga_init[] = "Oracle VM VirtualBox Version " VBOX_VERSION_STRING " VGA BIOS\r\n";
+
+/*
+ * Boot time harware inits
+ */
+void init_vga_card(void)
+{
+    /* Switch to color mode and enable CPU access 480 lines. */
+    outb(0x3C2, 0xC3);
+    /* More than 64k 3C4/04. */
+    /// @todo 16-bit write
+    outb(0x3C4, 0x04);
+    outb(0x3C5, 0x02);
+
+#ifdef DEBUG_VGA
+    printf(msg_vga_init);
+#endif
+}
+
+#include "vgatables.h"
+#include "vgadefs.h"
+
+// --------------------------------------------------------------------------------------------
+
+#pragma pack(0)
+
+/* Alphanumeric character set override. */
+typedef struct {
+    uint8_t       c_height;   /* Bytes/lines per character. */
+    uint8_t       cgen_bank;  /* Character generator bank. */
+    uint16_t      char_num;   /* Number of chars defined. */
+    uint16_t      char_1st;   /* First char code in table. */
+    uint16_t      font_ofs;   /* Font definition table offset. */
+    uint16_t      font_seg;   /* Font definition table segment. */
+    uint8_t       n_rows;     /* Number of text rows shown. */
+    uint8_t       modes[1];   /* Applicable modes list, 0xFF terminated. */
+} cso_txt;
+
+/* Graphics character set override. */
+typedef struct {
+    uint8_t       c_height;   /* Lines per character. */
+    uint16_t      c_len;      /* Bytes per character. */
+    uint16_t      font_ofs;   /* Font definition table offset. */
+    uint16_t      font_seg;   /* Font definition table segment. */
+    uint8_t       modes[1];   /* Applicable modes list, 0xFF terminated. */
+} cso_grf;
+
+struct dcc {
+    uint8_t     n_ent;
+    uint8_t     version;
+    uint8_t     max_code;
+    uint8_t     reserved;
+    uint16_t    dccs[16];
+} dcc_table = {
+    16,
+    1,
+    7,
+    0
+};
+
+struct ssa {
+    uint16_t    size;
+    void __far  *dcc;
+    void __far  *sacs;
+    void __far  *pal;
+    void __far  *resvd[3];
+
+} secondary_save_area = {
+    sizeof(struct ssa),
+    &dcc_table
+};
+
+void __far *video_save_pointer_table[7] = {
+    &video_param_table,
+    0,
+    0,
+    0,
+    &secondary_save_area
+};
+
+/*
+ *  Boot time bios area inits
+ */
+void init_bios_area(void)
+{
+    uint8_t __far   *bda;
+
+    bda = 0x40 :> 0;
+
+    /* Indicate 80x25 color was detected. */
+    bda[BIOSMEM_INITIAL_MODE] = (bda[BIOSMEM_INITIAL_MODE] & 0xcf) | 0x20;
+    /* Just for the first int10 find its children. */
+
+    /* The default char height. */
+    bda[BIOSMEM_CHAR_HEIGHT] = 16;
+    /* Clear the screen. */
+    bda[BIOSMEM_VIDEO_CTL]   = 0x60;
+    /* Set the basic screen we have. */
+    bda[BIOSMEM_SWITCHES]    = 0xf9;
+    /* Set the basic mode set options. */
+    bda[BIOSMEM_MODESET_CTL] = 0x51;
+    /* Set the default MSR. */
+    bda[BIOSMEM_CURRENT_MSR] = 0x09;
+    /* Initialize the default save area pointer. */
+    *(void __far * __far *)&bda[BIOSMEM_VS_POINTER] = video_save_pointer_table;
+}
+
+// ============================================================================================
+//
+// Init Entry point
+//
+// ============================================================================================
+void __far __cdecl vgabios_init_func(void)
+{
+    init_vga_card();
+    init_bios_area();
+#ifdef VBE
+    vbe_init();
+#endif
+    set_int_vector(0x10, vgabios_int10_handler);
+    set_int_vector(0x6D, vgabios_int10_handler);
+#ifdef CIRRUS
+    cirrus_init();
+#endif
+
+#ifndef VBOX
+    display_splash_screen();
+
+    // init video mode and clear the screen
+    // @@AS: Do not remove this init, because it will break VESA graphics
+    set_mode(3);
+
+    display_info();
+
+#ifdef VBE
+    vbe_display_info();
+#endif
+
+#ifdef CIRRUS
+    cirrus_display_info();
+#endif
+
+#else /* VBOX */
+
+//#ifdef DEBUG_bird
+    /* Init video mode and clear the screen */
+    set_mode(3);
+//#endif
+#endif /* VBOX */
+}
+
+#include "vgafonts.h"
+
+#ifndef VBOX
+// --------------------------------------------------------------------------------------------
+/*
+ *  Boot time Splash screen
+ */
+static void display_splash_screen()
+{
+}
+
+// --------------------------------------------------------------------------------------------
+/*
+ *  Tell who we are
+ */
+
+static void display_string(void)
+{
+ // Get length of string
+ASM_START
+ mov ax,ds
+ mov es,ax
+ mov di,si
+ xor cx,cx
+ not cx
+ xor al,al
+ cld
+ repne
+  scasb
+ not cx
+ dec cx
+ push cx
+
+ mov ax,#0x0300
+ mov bx,#0x0000
+ int #0x10
+
+ pop cx
+ mov ax,#0x1301
+ mov bx,#0x000b
+ mov bp,si
+ int #0x10
+ASM_END
+}
+
+static void display_info(void)
+{
+    display_string(vgabios_name);
+    display_string(vgabios_version);
+    display_string(vgabios_copyright);
+    display_string(vgabios_license);
+    display_string(vgabios_website);
+}
+
+#endif
+
+// --------------------------------------------------------------------------------------------
+#ifdef VGA_DEBUG
+void __cdecl int10_debugmsg(uint16_t DI, uint16_t SI, uint16_t BP, uint16_t SP, uint16_t BX,
+                            uint16_t DX, uint16_t CX, uint16_t AX, uint16_t DS, uint16_t ES, uint16_t FLAGS)
+{
+    /* Function 0Eh is write char and would generate way too much output. */
+    if (GET_AH() != 0x0E)
+        printf("vgabios call ah%02x al%02x bx%04x cx%04x dx%04x\n", GET_AH(), GET_AL(), BX, CX, DX);
+}
+#endif
+
+static void vga_get_cursor_pos(uint8_t page, uint16_t STACK_BASED *scans, uint16_t STACK_BASED *loc)
+{
+    if (page > 7) {
+        *scans = 0;
+        *loc   = 0;
+    } else {
+        // FIXME should handle VGA 14/16 lines
+        *scans = read_word(BIOSMEM_SEG,BIOSMEM_CURSOR_TYPE);
+        *loc   = read_word(BIOSMEM_SEG,BIOSMEM_CURSOR_POS + page * 2);
+    }
+}
+
+/* Look for a glyph bitmap in a given font. */
+static uint16_t vga_find_glyph(uint8_t __far *font, uint8_t STACK_BASED *glyph, uint8_t cp, uint16_t n_glyphs, uint8_t cheight)
+{
+    uint16_t    codepoint = 0;  /* Zero returned when glyph not found. */
+
+    while (n_glyphs--) {
+        if (!repe_cmpsb(font, glyph, cheight)) {
+            codepoint = cp | 0x8000;    /* Found matching glyph! */
+            break;
+        }
+        font += cheight;
+        ++cp;   /* Increment code point number. */
+    }
+    return codepoint;
+}
+
+static void vga_read_glyph_planar(uint8_t __far *vptr, uint16_t stride, uint8_t STACK_BASED *glyph, uint8_t cheight)
+{
+    /* Set Mode Register (GR5) to Read Mode 1. Assuming default register
+     * state from our mode set, this does all the hard work for us such that
+     * reading a byte from video memory gives us a bit mask for all eight
+     * pixels, for both 16-color and monochrome modes.
+     */
+    outw(VGAREG_GRDC_ADDRESS, 0x0805);
+
+    while (cheight--) {
+        *glyph++ = ~*vptr;
+        vptr += stride;
+    }
+
+    /* Put GR5 back to Read Mode 0. */
+    outw(VGAREG_GRDC_ADDRESS, 0x0005);
+}
+
+static uint16_t vga_char_ofs_planar(uint8_t xcurs, uint8_t ycurs, uint16_t nbcols, uint8_t page, uint8_t cheight)
+{
+    uint16_t    ofs;
+
+    ofs = ycurs * nbcols * cheight + xcurs;
+    ofs += page * read_word(BIOSMEM_SEG, BIOSMEM_PAGE_SIZE);
+
+    return ofs;
+}
+
+static uint8_t vga_read_char_planar(uint16_t nbcols, uint16_t ofs, uint8_t cheight)
+{
+    uint8_t     glyph[16];  /* NB: Don't try taller characters! */
+
+    vga_read_glyph_planar(0xA000 :> (uint8_t *)ofs, nbcols, &glyph, cheight);
+
+    /* Look through font pointed to by INT 43h. */
+    return vga_find_glyph((void __far *)read_dword(0, 0x43 * 4), &glyph, 0, 256, cheight);
+}
+
+static uint16_t vga_char_ofs_linear(uint8_t xcurs, uint8_t ycurs, uint16_t nbcols, uint8_t page, uint8_t cheight)
+{
+    uint16_t    ofs;
+
+    ofs = ycurs * nbcols * cheight + xcurs;
+    ofs *= 8;
+    return ofs;
+}
+
+static void vga_read_glyph_linear(uint8_t __far *vptr, uint16_t stride, uint8_t STACK_BASED *glyph, uint8_t cheight)
+{
+    uint8_t bmap, cbit;
+    int     i;
+
+    /* Zero pixels are background, everything else foreground. */
+    while (cheight--) {
+        bmap = 0;
+        cbit = 0x80;
+        for (i = 0; i < 8; ++i) {
+            if (vptr[i])
+                bmap |= cbit;
+            cbit >>= 1;
+        }
+        *glyph++ = bmap;
+        vptr += stride;
+    }
+}
+
+static uint8_t vga_read_char_linear(uint16_t nbcols, uint16_t ofs, uint8_t cheight)
+{
+    uint8_t     glyph[16];  /* NB: Don't try taller characters! */
+
+    vga_read_glyph_linear(0xA000 :> (uint8_t *)ofs, nbcols * 8, &glyph, cheight);
+
+    /* Look through font pointed to by INT 43h. */
+    return vga_find_glyph((void __far *)read_dword(0, 0x43 * 4), &glyph, 0, 256, cheight);
+}
+
+static uint8_t vga_read_2bpp_char(uint8_t __far *vptr)
+{
+    uint16_t    mask, pixb;
+    uint8_t     bmap, cbit;
+    int         i;
+
+    mask = 0xC000;  /* Check two bits at a time to see if they're zero. */
+    cbit = 0x80;    /* Go from left to right. */
+    bmap = 0;
+    pixb = swap_16(*((uint16_t __far *)vptr));
+    /* Go through 8 lines/words. */
+    for (i = 0; i < 8; ++i) {
+        if (pixb & mask)
+            bmap |= cbit;
+        cbit >>= 1;
+        mask >>= 2;
+    }
+    return bmap;
+}
+
+static void vga_read_glyph_cga(uint16_t ofs, uint8_t STACK_BASED *glyph, uint8_t mode)
+{
+    int             i;
+    uint8_t __far   *vptr;
+
+    /* The font size is fixed at 8x8. Stride is always 80 bytes because the
+     * mode is either 80 characters wide at 1bpp or 40 characters at 2bpp.
+     */
+    if (mode != 6) {
+        /* Adjust offset for 2bpp. */
+        vptr = 0xB800 :> (uint8_t *)(ofs * 2);
+        /* For 2bpp modes, we have to extract the bits by hand. */
+        for (i = 0; i < 4; ++i) {
+            *glyph++ = vga_read_2bpp_char(vptr);
+            *glyph++ = vga_read_2bpp_char(vptr + 0x2000);
+            vptr += 80;
+        }
+    } else {
+        vptr = 0xB800 :> (uint8_t *)ofs;
+        for (i = 0; i < 4; ++i) {
+            *glyph++ = vptr[0];
+            *glyph++ = vptr[0x2000];
+            vptr += 80;
+        }
+    }
+}
+
+static uint16_t vga_char_ofs_cga(uint8_t xcurs, uint8_t ycurs, uint16_t nbcols)
+{
+    /* Multiply ony by 8 due to line interleaving. NB: Caller
+     * has to multiply the result for two for 2bpp mode.
+     */
+    return ycurs * nbcols * 4 + xcurs;
+}
+
+static uint8_t vga_read_char_cga(uint16_t ofs, uint8_t mode)
+{
+    uint8_t     glyph[8];   /* Char height is hardcoded to 8. */
+    uint16_t    found;
+
+    /* Segment would be B000h for mono modes; we don't do those. */
+    vga_read_glyph_cga(ofs, &glyph, mode);
+
+    /* Look through the first half of the font pointed to by INT 43h. */
+    found = vga_find_glyph((void __far *)read_dword(0, 0x43 * 4), &glyph, 0, 128, 8);
+    /* If not found, look for the second half pointed to by INT 1Fh */
+    if (!(found & 0x8000)) {
+        void __far *int1f;
+
+        int1f = (void __far *)read_dword(0, 0x1f * 4);
+        if (int1f)  /* If null pointer, skip. */
+            found = vga_find_glyph(int1f, &glyph, 128, 128, 8);
+    }
+    return found;
+}
+
+static void vga_read_char_attr(uint8_t page, uint16_t STACK_BASED *chr_atr)
+{
+    uint8_t     xcurs, ycurs, mode, line, cheight;
+    uint16_t    nbcols, nbrows, address;
+    uint16_t    cursor, dummy, ofs;
+
+    // Get the mode
+    mode = read_byte(BIOSMEM_SEG, BIOSMEM_CURRENT_MODE);
+    line = find_vga_entry(mode);
+    if (line == 0xFF)
+        return;
+
+    // Get the cursor pos for the page
+    vga_get_cursor_pos(page, &dummy, &cursor);
+    xcurs = cursor & 0x00ff;
+    ycurs = (cursor & 0xff00) >> 8;
+
+    // Get the dimensions
+    nbrows = read_byte(BIOSMEM_SEG, BIOSMEM_NB_ROWS) + 1;
+    nbcols = read_word(BIOSMEM_SEG, BIOSMEM_NB_COLS);
+
+    if (vga_modes[line].class == TEXT) {
+        // Compute the address
+        address  = SCREEN_MEM_START(nbcols, nbrows, page) + (xcurs + ycurs * nbcols) * 2;
+        *chr_atr = read_word(vga_modes[line].sstart, address);
+    } else {
+        switch (vga_modes[line].memmodel) {
+        case CGA:
+            /* For CGA graphics, font size is hardcoded at 8x8. */
+            ofs = vga_char_ofs_cga(xcurs, ycurs, nbcols);
+            *chr_atr = vga_read_char_cga(ofs, mode);
+            break;
+        case PLANAR1:
+        case PLANAR4:
+            cheight = read_word(BIOSMEM_SEG, BIOSMEM_CHAR_HEIGHT);
+            ofs = vga_char_ofs_planar(xcurs, ycurs, nbcols, page, cheight);
+            *chr_atr = vga_read_char_planar(nbcols, ofs, cheight);
+            break;
+        case LINEAR8:
+            cheight = read_word(BIOSMEM_SEG, BIOSMEM_CHAR_HEIGHT);
+            ofs = vga_char_ofs_linear(xcurs, ycurs, nbcols, page, cheight);
+            *chr_atr = vga_read_char_linear(nbcols, ofs, cheight);
+            break;
+        default:
+#ifdef VGA_DEBUG
+            unimplemented();
+#endif
+            break;
+        }
+    }
+}
+
+static void vga_get_font_info (uint16_t func, uint16_t STACK_BASED *u_seg, uint16_t STACK_BASED *u_ofs,
+                               uint16_t STACK_BASED *c_height, uint16_t STACK_BASED *max_row)
+{
+    void    __far   *ptr;
+
+    switch (func) {
+    case 0x00:
+        ptr = (void __far *)read_dword(0x00, 0x1f * 4);
+        break;
+    case 0x01:
+        ptr = (void __far *)read_dword(0x00, 0x43 * 4);
+        break;
+    case 0x02:
+        ptr = vgafont14;
+        break;
+    case 0x03:
+        ptr = vgafont8;
+        break;
+    case 0x04:
+        ptr = vgafont8 + 128 * 8;
+        break;
+    case 0x05:
+        ptr = vgafont14alt;
+        break;
+    case 0x06:
+        ptr = vgafont16;
+        break;
+    case 0x07:
+        ptr = vgafont16alt;
+        break;
+    default:
+#ifdef VGA_DEBUG
+        printf("Get font info subfn(%02x) not implemented\n", func);
+#endif
+        return;
+    }
+    /* Split the far pointer and write it back. */
+    *u_ofs = (uint16_t)ptr;
+    *u_seg = (uint32_t)ptr >> 16;
+
+    /* The character height (effectively bytes per glyph). */
+    *c_height = read_byte(BIOSMEM_SEG, BIOSMEM_CHAR_HEIGHT);
+
+    /* The highest row number. */
+    *max_row = read_byte(BIOSMEM_SEG, BIOSMEM_NB_ROWS);
+}
+
+static void vga_read_pixel(uint8_t page, uint16_t col, uint16_t row, uint16_t STACK_BASED *pixel)
+{
+    uint8_t     mode, line, mask, attr, data, i;
+    uint16_t    addr;
+
+    /* Determine current mode characteristics. */
+    mode = read_byte(BIOSMEM_SEG, BIOSMEM_CURRENT_MODE);
+    line = find_vga_entry(mode);
+    if (line == 0xFF)
+        return;
+    if (vga_modes[line].class == TEXT)
+        return;
+
+    /* Read data depending on memory model. */
+    switch (vga_modes[line].memmodel) {
+    case PLANAR4:
+    case PLANAR1:
+        addr = col / 8 + row * read_word(BIOSMEM_SEG, BIOSMEM_NB_COLS);
+        addr += read_word(BIOSMEM_SEG, BIOSMEM_PAGE_SIZE) * page;
+        mask = 0x80 >> (col & 0x07);
+        attr = 0x00;
+        for (i = 0; i < 4; i++) {
+            outw(VGAREG_GRDC_ADDRESS, (i << 8) | 0x04);
+            data = read_byte(0xa000,addr) & mask;
+            if (data > 0)
+                attr |= (0x01 << i);
+        }
+        break;
+    case CGA:
+        addr = (col >> (4 - vga_modes[line].pixbits)) + (row >> 1) * 80;
+        if (row & 1)
+            addr += 0x2000;
+        data = read_byte(0xb800, addr);
+        if (vga_modes[line].pixbits == 2)
+            attr = (data >> ((3 - (col & 0x03)) * 2)) & 0x03;
+        else
+            attr = (data >> (7 - (col & 0x07))) & 0x01;
+        break;
+    case LINEAR8:
+        addr = col + row * (read_word(BIOSMEM_SEG, BIOSMEM_NB_COLS) * 8);
+        attr = read_byte(0xa000, addr);
+        break;
+    default:
+#ifdef VGA_DEBUG
+       unimplemented();
+#endif
+        attr = 0;
+    }
+    *(uint8_t STACK_BASED *)pixel = attr;
+}
+
+
+
+// --------------------------------------------------------------------------------------------
+/*static*/ void biosfn_perform_gray_scale_summing(uint16_t start, uint16_t count)
+{uint8_t r,g,b;
+ uint16_t i;
+ uint16_t index;
+
+ inb(VGAREG_ACTL_RESET);
+ outb(VGAREG_ACTL_ADDRESS,0x00);
+
+ for( index = 0; index < count; index++ )
+  {
+   // set read address and switch to read mode
+   outb(VGAREG_DAC_READ_ADDRESS,start);
+   // get 6-bit wide RGB data values
+   r=inb( VGAREG_DAC_DATA );
+   g=inb( VGAREG_DAC_DATA );
+   b=inb( VGAREG_DAC_DATA );
+
+   // intensity = ( 0.3 * Red ) + ( 0.59 * Green ) + ( 0.11 * Blue )
+   i = ( ( 77*r + 151*g + 28*b ) + 0x80 ) >> 8;
+
+   if(i>0x3f)i=0x3f;
+
+   // set write address and switch to write mode
+   outb(VGAREG_DAC_WRITE_ADDRESS,start);
+   // write new intensity value
+   outb( VGAREG_DAC_DATA, i&0xff );
+   outb( VGAREG_DAC_DATA, i&0xff );
+   outb( VGAREG_DAC_DATA, i&0xff );
+   start++;
+  }
+ inb(VGAREG_ACTL_RESET);
+ outb(VGAREG_ACTL_ADDRESS,0x20);
+#ifdef VBOX
+ inb(VGAREG_ACTL_RESET);
+#endif /* VBOX */
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_set_cursor_shape(uint8_t CH, uint8_t CL)
+{
+  uint16_t cheight, curs, crtc_addr;
+  int cga_emu;
+
+  /* Unmodified input is stored in the BDA. */
+  curs = (CH << 8) + CL;
+  write_word(BIOSMEM_SEG, BIOSMEM_CURSOR_TYPE, curs);
+
+  /* Check if VGA is active. If not, just write the input to the CRTC. */
+  if (!(read_byte(BIOSMEM_SEG, BIOSMEM_VIDEO_CTL) & 8)) {
+    /* Trying to disable the cursor? */
+    if ((CH & 0x60) == 0x20) {
+      /* Special IBM-compatible value to turn off cursor. */
+      CH = 0x1E;
+      CL = 0;
+    } else {
+      cga_emu = !(read_byte(BIOSMEM_SEG, BIOSMEM_VIDEO_CTL) & 1);
+
+      /* If CGA cursor emulation is on and this is a text mode, adjust.
+       * But if cursor star or end is bigger than 31, don't adjust.
+       */
+      /// @todo Figure out if this is a text mode
+      if (cga_emu /* && text mode*/ && (CH < 32) && (CL < 32)) {
+        cheight = read_word(BIOSMEM_SEG, BIOSMEM_CHAR_HEIGHT);
+
+        /* Is the end lower than start? VGA does not wrap around.*/
+        if (CL < CH) {
+          /* For zero CL (end), leave values unchanged. */
+          if (CL) {
+            CH = 0;
+            CL = cheight - 1;
+          }
+        } else {
+          if (((CL | CH) >= cheight) || ((CL != cheight - 1) && (CH != cheight - 2))) {
+            /* If it's an overbar cursor, don't adjust. */
+            if (CL > 3) {
+              if (CL <= CH + 2) {
+                /* It's it a normal underline style cursor. */
+                CH = CH - CL + cheight - 1;
+                CL = cheight - 1;
+                if (cheight >= 14) {
+                  /* Shift up one pixel for normal EGA/VGA fonts. */
+                  CL--;
+                  CH--;
+                }
+              } else if (CH <= 2) {
+                /* It's a full block cursor. */
+                CL = cheight - 1;
+              } else {
+                /* It's a half block cursor. */
+                CH = cheight / 2;
+                CL = cheight - 1;
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
+  // CTRC regs 0x0a and 0x0b
+  crtc_addr = read_word(BIOSMEM_SEG, BIOSMEM_CRTC_ADDRESS);
+  outb(crtc_addr, 0x0a);
+  outb(crtc_addr + 1, CH);
+  outb(crtc_addr, 0x0b);
+  outb(crtc_addr + 1 ,CL);
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_set_cursor_pos (uint8_t page, uint16_t cursor)
+{
+ uint8_t xcurs,ycurs,current;
+ uint16_t nbcols,nbrows,address,crtc_addr;
+
+ // Should not happen...
+ if(page>7)return;
+
+ // Bios cursor pos
+ write_word(BIOSMEM_SEG, BIOSMEM_CURSOR_POS+2*page, cursor);
+
+ // Set the hardware cursor
+ current=read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE);
+ if(page==current)
+  {
+   // Get the dimensions
+   nbcols=read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS);
+   nbrows=read_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS)+1;
+
+   xcurs=cursor&0x00ff;ycurs=(cursor&0xff00)>>8;
+
+   // Calculate the address knowing nbcols nbrows and page num
+   address=SCREEN_IO_START(nbcols,nbrows,page)+xcurs+ycurs*nbcols;
+
+   // CRTC regs 0x0e and 0x0f
+   crtc_addr=read_word(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS);
+   outb(crtc_addr,0x0e);
+   outb(crtc_addr+1,(address&0xff00)>>8);
+   outb(crtc_addr,0x0f);
+   outb(crtc_addr+1,address&0x00ff);
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_set_active_page(uint8_t page)
+{
+ uint16_t cursor,dummy,crtc_addr;
+ uint16_t nbcols,nbrows,address;
+ uint8_t mode,line;
+
+ if(page>7)return;
+
+ // Get the mode
+ mode=read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE);
+ line=find_vga_entry(mode);
+ if(line==0xFF)return;
+
+ // Get pos curs pos for the right page
+ vga_get_cursor_pos(page,&dummy,&cursor);
+
+ if(vga_modes[line].class==TEXT)
+  {
+   // Get the dimensions
+   nbcols=read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS);
+   nbrows=read_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS)+1;
+
+   // Calculate the address knowing nbcols nbrows and page num
+   address=SCREEN_MEM_START(nbcols,nbrows,page);
+   write_word(BIOSMEM_SEG,BIOSMEM_CURRENT_START,address);
+
+   // Start address
+   address=SCREEN_IO_START(nbcols,nbrows,page);
+  }
+ else
+  {
+   address = page * video_param_table[line_to_vpti[line]].slength;
+  }
+
+ // CRTC regs 0x0c and 0x0d
+ crtc_addr=read_word(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS);
+ outb(crtc_addr,0x0c);
+ outb(crtc_addr+1,(address&0xff00)>>8);
+ outb(crtc_addr,0x0d);
+ outb(crtc_addr+1,address&0x00ff);
+
+ // And change the BIOS page
+ write_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE,page);
+
+#ifdef VGA_DEBUG
+ printf("Set active page %02x address %04x\n",page,address);
+#endif
+
+ // Display the cursor, now the page is active
+ biosfn_set_cursor_pos(page,cursor);
+}
+
+/// Recursive BIOS invocation, uses vector 6Dh
+extern void vga_font_set(uint8_t function, uint8_t data);
+#pragma aux vga_font_set =  \
+    "mov    ah, 11h"        \
+    "int    6Dh"            \
+    parm [al] [bl];
+
+// ============================================================================================
+//
+// BIOS functions
+//
+// ============================================================================================
+
+/* CGA-compatible MSR (0x3D8) register values for first modes 0-7. */
+uint8_t cga_msr[8] = {
+    0x2C, 0x28, 0x2D, 0x29, 0x2A, 0x2E, 0x1E, 0x29
+};
+
+/* Convert index in vga_modes[] to index in video_param_table[] for 200-line (CGA) text modes. */
+static int8_t line_to_vpti_200[8] = {
+    0x00, 0x01, 0x02, 0x03, -1, -1, -1, 0x07
+};
+
+/* Same for 350-line (EGA) text modes. */
+static int8_t line_to_vpti_350[8] = {
+    0x13, 0x14, 0x15, 0x16, -1, -1, -1, 0x07
+};
+
+/* Same for 400-line (VGA) text modes. */
+static int8_t line_to_vpti_400[8] = {
+    0x17, 0x17, 0x18, 0x18, -1, -1, -1, 0x19
+};
+
+int find_vpti(uint8_t line)
+{
+    int         idx;
+    uint8_t     mctl;
+
+    if (vga_modes[line].class == TEXT) {
+        mctl = read_byte(BIOSMEM_SEG, BIOSMEM_MODESET_CTL);
+        if (mctl & 0x10)
+            idx = line_to_vpti_400[line];
+        else if (mctl & 0x80)
+            idx = line_to_vpti_200[line];
+        else
+            idx = line_to_vpti_350[line];
+    } else
+        idx = line_to_vpti[line];
+
+    return idx;
+}
+
+static void biosfn_load_text_user_pat(uint8_t AL, uint16_t ES, uint16_t BP, uint16_t CX, uint16_t DX, uint8_t BL, uint8_t BH);
+static void load_text_patch(uint16_t ES, uint16_t BP, uint8_t BL, uint8_t BH);
+
+void biosfn_set_video_mode(uint8_t mode)
+{// mode: Bit 7 is 1 if no clear screen
+
+ // Should we clear the screen ?
+ uint8_t  noclearmem=mode&0x80;
+ uint8_t  line,mmask,vpti;
+ uint8_t  modeset_ctl;
+ uint8_t  *palette;
+ uint16_t i;
+ uint16_t crtc_addr;
+ void __far * __far *save_area;
+ VideoParamTableEntry __far *vpt;
+
+#ifdef VBE
+ if (vbe_has_vbe_display()) {
+   // Force controller into VGA mode
+   outb(VGAREG_SEQU_ADDRESS,7);
+   outb(VGAREG_SEQU_DATA,0x00);
+  }
+#endif // def VBE
+
+ // The real mode
+ mode=mode&0x7f;
+
+ // Display switching is not supported; mono monitors aren't really either,
+ // but requests to set mode 7 are honored.
+
+ // find the entry in the video modes
+ line=find_vga_entry(mode);
+
+#ifdef VGA_DEBUG
+ printf("mode search %02x found line %02x\n",mode,line);
+#endif
+
+ if(line==0xFF)
+  return;
+
+ // Read the save area pointer.
+ save_area = (void __far *)read_dword(BIOSMEM_SEG, BIOSMEM_VS_POINTER);
+
+ vpti = find_vpti(line);
+ vpt  = save_area[0];
+ vpt += vpti;
+
+#if 0   // These are unused, but perhaps they shouldn't be?
+ // Read the bios vga control
+ video_ctl=read_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL);
+
+ // Read the bios vga switches
+ vga_switches=read_byte(BIOSMEM_SEG,BIOSMEM_SWITCHES);
+#endif
+
+ // Read the bios mode set control
+ modeset_ctl=read_byte(BIOSMEM_SEG,BIOSMEM_MODESET_CTL);
+
+ // Then we know the number of lines
+// FIXME
+
+ // if palette loading (bit 3 of modeset ctl = 0)
+ if((modeset_ctl&0x08)==0)
+  {// Set the PEL mask
+   outb(VGAREG_PEL_MASK,vga_modes[line].pelmask);
+
+   // Set the whole dac always, from 0
+   outb(VGAREG_DAC_WRITE_ADDRESS,0x00);
+
+   // From which palette
+   switch(vga_modes[line].dacmodel)
+    {case 0:
+      palette=&palette0[0];
+      break;
+     case 1:
+      palette=&palette1[0];
+      break;
+     case 2:
+      palette=&palette2[0];
+      break;
+     case 3:
+      palette=&palette3[0];
+      break;
+    }
+   // Override for CGA text modes.
+   if(vga_modes[line].class==TEXT)
+    {
+     if(vpt->cheight == 8) // CGA
+      palette=&palette1[0];
+    }
+   // Always 256*3 values
+   for(i=0;i<0x0100;i++)
+    {if(i<=dac_regs[vga_modes[line].dacmodel])
+      {outb(VGAREG_DAC_DATA,palette[(i*3)+0]);
+       outb(VGAREG_DAC_DATA,palette[(i*3)+1]);
+       outb(VGAREG_DAC_DATA,palette[(i*3)+2]);
+      }
+     else
+      {outb(VGAREG_DAC_DATA,0);
+       outb(VGAREG_DAC_DATA,0);
+       outb(VGAREG_DAC_DATA,0);
+      }
+    }
+   if((modeset_ctl&0x02)==0x02)
+    {
+     biosfn_perform_gray_scale_summing(0x00, 0x100);
+    }
+  }
+
+ // Reset Attribute Ctl flip-flop
+ inb(VGAREG_ACTL_RESET);
+
+ // Set Attribute Ctl
+ for(i=0;i<=0x13;i++)
+  {outb(VGAREG_ACTL_ADDRESS,i);
+   outb(VGAREG_ACTL_WRITE_DATA,vpt->actl_regs[i]);
+  }
+ outb(VGAREG_ACTL_ADDRESS,0x14);
+ outb(VGAREG_ACTL_WRITE_DATA,0x00);
+
+ // Save palette into the save area if it exists.
+ if(save_area[1])
+ {
+    uint8_t __far *dyn_save;
+
+    dyn_save = save_area[1];
+    for (i = 0; i < 16; ++i)
+       dyn_save[i] = vpt->actl_regs[i];
+    dyn_save[16] = vpt->actl_regs[17];
+ }
+
+ // Set Sequencer Ctl
+ outb(VGAREG_SEQU_ADDRESS,0);
+ outb(VGAREG_SEQU_DATA,0x03);
+ for(i=1;i<=4;i++)
+  {outb(VGAREG_SEQU_ADDRESS,i);
+   outb(VGAREG_SEQU_DATA,vpt->sequ_regs[i - 1]);
+  }
+
+ // Set Grafx Ctl
+ for(i=0;i<=8;i++)
+  {outb(VGAREG_GRDC_ADDRESS,i);
+   outb(VGAREG_GRDC_DATA,vpt->grdc_regs[i]);
+  }
+
+ // Set CRTC address VGA or MDA
+ crtc_addr=vga_modes[line].memmodel==MTEXT?VGAREG_MDA_CRTC_ADDRESS:VGAREG_VGA_CRTC_ADDRESS;
+
+  // Set the misc register; may change CRTC base!
+ outb(VGAREG_WRITE_MISC_OUTPUT,vpt->miscreg);
+
+ // Disable CRTC write protection
+ outw(crtc_addr,0x0011);
+ // Set CRTC regs
+ for(i=0;i<=0x18;i++)
+  {outb(crtc_addr,i);
+   outb(crtc_addr+1,vpt->crtc_regs[i]);
+  }
+
+ // Enable video
+ outb(VGAREG_ACTL_ADDRESS,0x20);
+ inb(crtc_addr + VGAREG_ACTL_RESET - VGAREG_VGA_CRTC_ADDRESS);
+
+ if(noclearmem==0x00)
+  {
+   if(vga_modes[line].class==TEXT)
+    {
+     memsetw(vga_modes[line].sstart,0,0x0720,0x4000); // 32k
+    }
+   else
+    {
+     if(mode<0x0d)
+      {
+       memsetw(vga_modes[line].sstart,0,0x0000,0x4000); // 32k
+      }
+     else
+      {
+       outb( VGAREG_SEQU_ADDRESS, 0x02 );
+       mmask = inb( VGAREG_SEQU_DATA );
+       outb( VGAREG_SEQU_DATA, 0x0f ); // all planes
+       memsetw(vga_modes[line].sstart,0,0x0000,0x8000); // 64k
+       outb( VGAREG_SEQU_DATA, mmask );
+      }
+    }
+  }
+
+ // Set the BIOS mem
+ write_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE,mode);
+ write_word(BIOSMEM_SEG,BIOSMEM_NB_COLS,vpt->twidth);
+ write_word(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE,vpt->slength);
+ write_word(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS,crtc_addr);
+ write_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS,vpt->theightm1);
+ write_word(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT,vpt->cheight);
+ write_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL,(0x60|noclearmem));
+ write_byte(BIOSMEM_SEG,BIOSMEM_SWITCHES,0xF9);
+
+ // FIXME We nearly have the good tables. to be reworked
+ write_byte(BIOSMEM_SEG,BIOSMEM_DCC_INDEX,0x08);    // 8 is VGA should be ok for now
+
+ if (mode <= 7)
+ {
+     write_byte(BIOSMEM_SEG, BIOSMEM_CURRENT_MSR, cga_msr[mode]);           /* Like CGA reg. 0x3D8 */
+     write_byte(BIOSMEM_SEG, BIOSMEM_CURRENT_PAL, mode == 6 ? 0x3F : 0x30); /* Like CGA reg. 0x3D9*/
+ }
+
+ // Set cursor shape
+ if(vga_modes[line].class==TEXT)
+  {
+   biosfn_set_cursor_shape(0x06,0x07);
+  }
+
+ /// @todo Could be optimized to a memset since only BDA needs updating.
+ // Set cursor pos for page 0..7
+ for(i=0;i<8;i++)
+  biosfn_set_cursor_pos(i,0x0000);
+
+ // Set active page 0
+ biosfn_set_active_page(0x00);
+
+ // Write the fonts in memory
+ if(vga_modes[line].class==TEXT)
+  {
+     cso_txt __far   *ovr = save_area[2];
+
+     switch (vpt->cheight) {
+     case 8:
+         biosfn_load_text_user_pat(0, 0xC000, (uint16_t)vgafont8,  256, 0, 0, vpt->cheight);
+         break;
+     case 14:
+         biosfn_load_text_user_pat(0, 0xC000, (uint16_t)vgafont14, 256, 0, 0, vpt->cheight);
+         if (mode == 7) /* 350-line EGA modes are 640 wide, only mono EGA mode is 720 wide. */
+             load_text_patch(0xC000, (uint16_t)vgafont14alt, 0, 14);
+         break;
+     default:
+         biosfn_load_text_user_pat(0, 0xC000, (uint16_t)vgafont16, 256, 0, 0, vpt->cheight);
+         load_text_patch(0xC000, (uint16_t)vgafont16alt, 0, 16);
+     }
+     if (ovr)
+      {
+#ifdef VGA_DEBUG
+         printf("Charmap override found, font at %04x:%04x\n", ovr->font_seg, ovr->font_ofs);
+#endif
+         i = 0;
+         // Does the override support current mode?
+         while (ovr->modes[i] != 0xff)
+          {
+             if (ovr->modes[i] == mode)
+                break;
+             ++i;
+          }
+         // If there is a valid font override, apply it.
+         if (ovr->modes[i] == mode)
+          {
+#ifdef VGA_DEBUG
+             printf("Loading override, %04x chars, height %02x\n", ovr->char_num, ovr->c_height);
+#endif
+             biosfn_load_text_user_pat(0x10, ovr->font_seg, ovr->font_ofs, ovr->char_num,
+                                       ovr->char_1st, ovr->cgen_bank, ovr->c_height);
+          }
+      }
+     vga_font_set(0x03, 0);                 /* Select font page mode 0. */
+  }
+
+ // Set the ints 0x1F and 0x43
+ set_int_vector(0x1f, vgafont8+128*8);
+
+  switch(vpt->cheight)
+   {case 8:
+     set_int_vector(0x43, vgafont8);
+     break;
+    case 14:
+     set_int_vector(0x43, vgafont14);
+     break;
+    case 16:
+     set_int_vector(0x43, vgafont16);
+     break;
+   }
+}
+
+// --------------------------------------------------------------------------------------------
+static void vgamem_copy_pl4(uint8_t xstart, uint8_t ysrc, uint8_t ydest,
+                            uint8_t cols, uint8_t nbcols, uint8_t cheight)
+{
+ uint16_t src,dest;
+ uint8_t i;
+
+ src=ysrc*cheight*nbcols+xstart;
+ dest=ydest*cheight*nbcols+xstart;
+ outw(VGAREG_GRDC_ADDRESS, 0x0105);
+ for(i=0;i<cheight;i++)
+  {
+   memcpyb(0xa000,dest+i*nbcols,0xa000,src+i*nbcols,cols);
+  }
+ outw(VGAREG_GRDC_ADDRESS, 0x0005);
+}
+
+// --------------------------------------------------------------------------------------------
+static void vgamem_fill_pl4(uint8_t xstart, uint8_t ystart, uint8_t cols,
+                            uint8_t nbcols, uint8_t cheight, uint8_t attr)
+{
+ uint16_t dest;
+ uint8_t i;
+
+ dest=ystart*cheight*nbcols+xstart;
+ outw(VGAREG_GRDC_ADDRESS, 0x0205);
+ for(i=0;i<cheight;i++)
+  {
+   memsetb(0xa000,dest+i*nbcols,attr,cols);
+  }
+ outw(VGAREG_GRDC_ADDRESS, 0x0005);
+}
+
+// --------------------------------------------------------------------------------------------
+static void vgamem_copy_cga(uint8_t xstart, uint8_t ysrc, uint8_t ydest,
+                            uint8_t cols, uint8_t nbcols, uint8_t cheight)
+{
+ uint16_t src,dest;
+ uint8_t i;
+
+ src=((ysrc*cheight*nbcols)>>1)+xstart;
+ dest=((ydest*cheight*nbcols)>>1)+xstart;
+ for(i=0;i<cheight/2;i++)
+  {
+   memcpyb(0xb800,dest+i*nbcols,0xb800,src+i*nbcols,cols);
+   memcpyb(0xb800,0x2000+dest+i*nbcols,0xb800,0x2000+src+i*nbcols,cols);
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void vgamem_fill_cga(uint8_t xstart, uint8_t ystart, uint8_t cols,
+                            uint8_t nbcols, uint8_t cheight, uint8_t attr)
+{
+ uint16_t dest;
+ uint8_t i;
+
+ dest=((ystart*cheight*nbcols)>>1)+xstart;
+ for(i=0;i<cheight/2;i++)
+  {
+   memsetb(0xb800,dest+i*nbcols,attr,cols);
+   memsetb(0xb800,0x2000+dest+i*nbcols,attr,cols);
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void vgamem_copy_linear(uint8_t xstart, uint8_t ysrc, uint8_t ydest,
+                               uint16_t cols, uint16_t nbcols, uint8_t cheight)
+{
+ uint16_t src,dest;
+ uint8_t i;
+
+ src=((ysrc*cheight*nbcols)+xstart)*8;
+ dest=((ydest*cheight*nbcols)+xstart)*8;
+ cols*=8;
+ nbcols*=8;
+ for(i=0;i<cheight;i++)
+  {
+   memcpyb(0xa000,dest+i*nbcols,0xa000,src+i*nbcols,cols);
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void vgamem_fill_linear(uint8_t xstart, uint8_t ystart, uint16_t cols,
+                               uint16_t nbcols, uint8_t cheight, uint8_t attr)
+{
+ uint16_t dest;
+ uint8_t i;
+
+ dest=((ystart*cheight*nbcols)+xstart)*8;
+ cols*=8;
+ nbcols*=8;
+ for(i=0;i<cheight;i++)
+  {
+   memsetb(0xa000,dest+i*nbcols,attr,cols);
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_scroll(uint8_t nblines, uint8_t attr, uint8_t rul, uint8_t cul,
+                          uint8_t rlr, uint8_t clr, uint8_t page, uint8_t dir)
+{
+ // page == 0xFF if current
+
+ uint8_t mode,line,cheight,bpp,cols;
+ uint16_t nbcols,nbrows,i;
+ uint16_t address;
+
+ if(rul>rlr)return;
+ if(cul>clr)return;
+
+ // Get the mode
+ mode=read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE);
+ line=find_vga_entry(mode);
+ if(line==0xFF)return;
+
+ // Get the dimensions
+ nbrows=read_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS)+1;
+ nbcols=read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS);
+
+ // Get the current page
+ if(page==0xFF)
+  page=read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE);
+
+ if(rlr>=nbrows)rlr=nbrows-1;
+ if(clr>=nbcols)clr=nbcols-1;
+ if(nblines>nbrows)nblines=0;
+ cols=clr-cul+1;
+
+ if(vga_modes[line].class==TEXT)
+  {
+   // Compute the address
+   address=SCREEN_MEM_START(nbcols,nbrows,page);
+#ifdef VGA_DEBUG
+   printf("Scroll, address %04x (%04x %04x %02x)\n",address,nbrows,nbcols,page);
+#endif
+
+   if(nblines==0&&rul==0&&cul==0&&rlr==nbrows-1&&clr==nbcols-1)
+    {
+     memsetw(vga_modes[line].sstart,address,(uint16_t)attr*0x100+' ',nbrows*nbcols);
+    }
+   else
+    {// if Scroll up
+     if(dir==SCROLL_UP)
+      {for(i=rul;i<=rlr;i++)
+        {
+         if((i+nblines>rlr)||(nblines==0))
+          memsetw(vga_modes[line].sstart,address+(i*nbcols+cul)*2,(uint16_t)attr*0x100+' ',cols);
+         else
+          memcpyw(vga_modes[line].sstart,address+(i*nbcols+cul)*2,vga_modes[line].sstart,((i+nblines)*nbcols+cul)*2,cols);
+        }
+      }
+     else
+      {for(i=rlr;i>=rul;i--)
+        {
+         if((i<rul+nblines)||(nblines==0))
+          memsetw(vga_modes[line].sstart,address+(i*nbcols+cul)*2,(uint16_t)attr*0x100+' ',cols);
+         else
+          memcpyw(vga_modes[line].sstart,address+(i*nbcols+cul)*2,vga_modes[line].sstart,((i-nblines)*nbcols+cul)*2,cols);
+         if (i>rlr) break;
+        }
+      }
+    }
+  }
+ else
+  {
+   cheight=video_param_table[line_to_vpti[line]].cheight;
+   switch(vga_modes[line].memmodel)
+    {
+     case PLANAR4:
+     case PLANAR1:
+       if(nblines==0&&rul==0&&cul==0&&rlr==nbrows-1&&clr==nbcols-1)
+        {
+         outw(VGAREG_GRDC_ADDRESS, 0x0205);
+         memsetb(vga_modes[line].sstart,0,attr,nbrows*nbcols*cheight);
+         outw(VGAREG_GRDC_ADDRESS, 0x0005);
+        }
+       else
+        {// if Scroll up
+         if(dir==SCROLL_UP)
+          {for(i=rul;i<=rlr;i++)
+            {
+             if((i+nblines>rlr)||(nblines==0))
+              vgamem_fill_pl4(cul,i,cols,nbcols,cheight,attr);
+             else
+              vgamem_copy_pl4(cul,i+nblines,i,cols,nbcols,cheight);
+            }
+          }
+         else
+          {for(i=rlr;i>=rul;i--)
+            {
+             if((i<rul+nblines)||(nblines==0))
+              vgamem_fill_pl4(cul,i,cols,nbcols,cheight,attr);
+             else
+              vgamem_copy_pl4(cul,i-nblines,i,cols,nbcols,cheight);
+             if (i>rlr) break;
+            }
+          }
+        }
+       break;
+     case CGA:
+       bpp=vga_modes[line].pixbits;
+       if(nblines==0&&rul==0&&cul==0&&rlr==nbrows-1&&clr==nbcols-1)
+        {
+         memsetb(vga_modes[line].sstart,0,attr,nbrows*nbcols*cheight*bpp);
+        }
+       else
+        {
+         if(bpp==2)
+          {
+           cul<<=1;
+           cols<<=1;
+           nbcols<<=1;
+          }
+         // if Scroll up
+         if(dir==SCROLL_UP)
+          {for(i=rul;i<=rlr;i++)
+            {
+             if((i+nblines>rlr)||(nblines==0))
+              vgamem_fill_cga(cul,i,cols,nbcols,cheight,attr);
+             else
+              vgamem_copy_cga(cul,i+nblines,i,cols,nbcols,cheight);
+            }
+          }
+         else
+          {for(i=rlr;i>=rul;i--)
+            {
+             if((i<rul+nblines)||(nblines==0))
+              vgamem_fill_cga(cul,i,cols,nbcols,cheight,attr);
+             else
+              vgamem_copy_cga(cul,i-nblines,i,cols,nbcols,cheight);
+             if (i>rlr) break;
+            }
+          }
+        }
+       break;
+     case LINEAR8:
+       if(nblines==0&&rul==0&&cul==0&&rlr==nbrows-1&&clr==nbcols-1)
+        {
+         memsetb(vga_modes[line].sstart,0,attr,nbrows*nbcols*cheight*8);
+        }
+       else
+        {
+         // if Scroll up
+         if(dir==SCROLL_UP)
+          {for(i=rul;i<=rlr;i++)
+            {
+             if((i+nblines>rlr)||(nblines==0))
+              vgamem_fill_linear(cul,i,cols,nbcols,cheight,attr);
+             else
+              vgamem_copy_linear(cul,i+nblines,i,cols,nbcols,cheight);
+            }
+          }
+         else
+          {for(i=rlr;i>=rul;i--)
+            {
+             if((i<rul+nblines)||(nblines==0))
+              vgamem_fill_linear(cul,i,cols,nbcols,cheight,attr);
+             else
+              vgamem_copy_linear(cul,i-nblines,i,cols,nbcols,cheight);
+             if (i>rlr) break;
+            }
+          }
+        }
+       break;
+#ifdef VGA_DEBUG
+     default:
+       printf("Scroll in graphics mode ");
+       unimplemented();
+#endif
+    }
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void write_gfx_char_pl4(uint8_t car, uint8_t attr, uint8_t xcurs,
+                               uint8_t ycurs, uint8_t nbcols, uint8_t cheight, uint8_t page)
+{
+ uint8_t i,j,mask;
+ uint8_t __far *fdata;
+ uint16_t addr,dest,src;
+
+ fdata = (void __far *)read_dword(0x00, 0x43 * 4);
+
+ addr=xcurs+ycurs*cheight*nbcols;
+ addr+=read_word(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE)*page;
+ src = car * cheight;
+ outw(VGAREG_SEQU_ADDRESS, 0x0f02);
+ outw(VGAREG_GRDC_ADDRESS, 0x0205);
+ if(attr&0x80)
+  {
+   outw(VGAREG_GRDC_ADDRESS, 0x1803);
+  }
+ else
+  {
+   outw(VGAREG_GRDC_ADDRESS, 0x0003);
+  }
+ for(i=0;i<cheight;i++)
+  {
+   dest=addr+i*nbcols;
+   for(j=0;j<8;j++)
+    {
+     mask=0x80>>j;
+     outw(VGAREG_GRDC_ADDRESS, (mask << 8) | 0x08);
+     readx_byte(0xa000,dest);
+     if(fdata[src+i]&mask)
+      {
+       write_byte(0xa000,dest,attr&0x0f);
+      }
+     else
+      {
+       write_byte(0xa000,dest,0x00);
+      }
+    }
+  }
+  outw(VGAREG_GRDC_ADDRESS, 0xff08);
+  outw(VGAREG_GRDC_ADDRESS, 0x0005);
+  outw(VGAREG_GRDC_ADDRESS, 0x0003);
+}
+
+// --------------------------------------------------------------------------------------------
+static void write_gfx_char_cga(uint8_t car, uint8_t attr, uint8_t xcurs,
+                               uint8_t ycurs, uint8_t nbcols, uint8_t bpp)
+{
+ uint8_t i,j,mask,data;
+ uint8_t *fdata;
+ uint16_t addr,dest,src;
+
+ fdata = &vgafont8;
+ addr=(xcurs*bpp)+ycurs*320;
+ src = car * 8;
+ for(i=0;i<8;i++)
+  {
+   dest=addr+(i>>1)*80;
+   if (i & 1) dest += 0x2000;
+   mask = 0x80;
+   /* NB: In 1bpp modes, the attribute is ignored, only the XOR flag has meaning. */
+   if (bpp == 1)
+    {
+     if (attr & 0x80)
+      {
+       data = read_byte(0xb800,dest);
+       data ^= fdata[src+i];
+      }
+     else
+      {
+       data = fdata[src+i];
+      }
+     write_byte(0xb800,dest,data);
+    }
+   else
+    {
+     while (mask > 0)
+      {
+       if (attr & 0x80)
+        {
+         data = read_byte(0xb800,dest);
+        }
+       else
+        {
+         data = 0x00;
+        }
+       for(j=0;j<4;j++)
+        {
+         if (fdata[src+i] & mask)
+          {
+           if (attr & 0x80)
+            {
+             data ^= (attr & 0x03) << ((3-j)*2);
+            }
+           else
+            {
+             data |= (attr & 0x03) << ((3-j)*2);
+            }
+          }
+         mask >>= 1;
+        }
+       write_byte(0xb800,dest,data);
+       dest += 1;
+      }
+    }
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void write_gfx_char_lin(uint8_t car, uint8_t attr, uint8_t xcurs,
+                               uint8_t ycurs, uint8_t nbcols)
+{
+ uint8_t i,j,mask,data;
+ uint8_t *fdata;
+ uint16_t addr,dest,src;
+
+ fdata = &vgafont8;
+ addr=xcurs*8+ycurs*nbcols*64;
+ src = car * 8;
+ for(i=0;i<8;i++)
+  {
+   dest=addr+i*nbcols*8;
+   mask = 0x80;
+   for(j=0;j<8;j++)
+    {
+     data = 0x00;
+     if (fdata[src+i] & mask)
+      {
+       data = attr;
+      }
+     write_byte(0xa000,dest+j,data);
+     mask >>= 1;
+    }
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_write_char_attr(uint8_t car, uint8_t page, uint8_t attr, uint16_t count)
+{
+ uint8_t cheight,xcurs,ycurs,mode,line,bpp;
+ uint16_t nbcols,nbrows,address;
+ uint16_t cursor,dummy;
+
+ // Get the mode
+ mode=read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE);
+ line=find_vga_entry(mode);
+ if(line==0xFF)return;
+
+ // Get the cursor pos for the page
+ vga_get_cursor_pos(page,&dummy,&cursor);
+ xcurs=cursor&0x00ff;ycurs=(cursor&0xff00)>>8;
+
+ // Get the dimensions
+ nbrows=read_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS)+1;
+ nbcols=read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS);
+
+ if(vga_modes[line].class==TEXT)
+  {
+   // Compute the address
+   address=SCREEN_MEM_START(nbcols,nbrows,page)+(xcurs+ycurs*nbcols)*2;
+
+   dummy=((uint16_t)attr<<8)+car;
+   memsetw(vga_modes[line].sstart,address,dummy,count);
+  }
+ else
+  {
+   // FIXME gfx mode not complete
+   cheight=video_param_table[line_to_vpti[line]].cheight;
+   bpp=vga_modes[line].pixbits;
+   while(count-->0)
+    {
+     switch(vga_modes[line].memmodel)
+      {
+       case PLANAR1:
+         attr |= 0x01;  /* Color is ignored in 1bpp modes, always foreground. */
+       case PLANAR4:
+         write_gfx_char_pl4(car,attr,xcurs,ycurs,nbcols,cheight,page);
+         break;
+       case CGA:
+         write_gfx_char_cga(car,attr,xcurs,ycurs,nbcols,bpp);
+         break;
+       case LINEAR8:
+         write_gfx_char_lin(car,attr,xcurs,ycurs,nbcols);
+         break;
+#ifdef VGA_DEBUG
+       default:
+         unimplemented();
+#endif
+      }
+     xcurs++;
+    }
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_write_char_only(uint8_t car, uint8_t page, uint8_t attr, uint16_t count)
+{
+ uint8_t cheight,xcurs,ycurs,mode,line,bpp;
+ uint16_t nbcols,nbrows,address;
+ uint16_t cursor,dummy;
+
+ // Get the mode
+ mode=read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE);
+ line=find_vga_entry(mode);
+ if(line==0xFF)return;
+
+ // Get the cursor pos for the page
+ vga_get_cursor_pos(page,&dummy,&cursor);
+ xcurs=cursor&0x00ff;ycurs=(cursor&0xff00)>>8;
+
+ // Get the dimensions
+ nbrows=read_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS)+1;
+ nbcols=read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS);
+
+ if(vga_modes[line].class==TEXT)
+  {
+   // Compute the address
+   address=SCREEN_MEM_START(nbcols,nbrows,page)+(xcurs+ycurs*nbcols)*2;
+
+   while(count-->0)
+    {write_byte(vga_modes[line].sstart,address,car);
+     address+=2;
+    }
+  }
+ else
+  {
+   // FIXME gfx mode not complete
+   cheight=video_param_table[line_to_vpti[line]].cheight;
+   bpp=vga_modes[line].pixbits;
+   while(count-->0)
+    {
+     switch(vga_modes[line].memmodel)
+      {
+       case PLANAR1:
+         attr |= 0x01;  /* Color is ignored in 1bpp modes, always foreground. */
+       case PLANAR4:
+         write_gfx_char_pl4(car,attr,xcurs,ycurs,nbcols,cheight,page);
+         break;
+       case CGA:
+         write_gfx_char_cga(car,attr,xcurs,ycurs,nbcols,bpp);
+         break;
+       case LINEAR8:
+         write_gfx_char_lin(car,attr,xcurs,ycurs,nbcols);
+         break;
+#ifdef VGA_DEBUG
+       default:
+         unimplemented();
+#endif
+      }
+     xcurs++;
+    }
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_write_pixel(uint8_t BH, uint8_t AL, uint16_t CX, uint16_t DX)
+{
+ uint8_t mode,line,mask,attr,data;
+ uint16_t addr;
+
+ // Get the mode
+ mode=read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE);
+ line=find_vga_entry(mode);
+ if(line==0xFF)return;
+ if(vga_modes[line].class==TEXT)return;
+
+ switch(vga_modes[line].memmodel)
+  {
+   case PLANAR4:
+   case PLANAR1:
+     addr = CX/8+DX*read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS);
+     addr += read_word(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE) * BH;
+     mask = 0x80 >> (CX & 0x07);
+     outw(VGAREG_GRDC_ADDRESS, (mask << 8) | 0x08);
+     outw(VGAREG_GRDC_ADDRESS, 0x0205);
+     data = readx_byte(0xa000,addr);
+     if (AL & 0x80)
+      {
+       outw(VGAREG_GRDC_ADDRESS, 0x1803);
+      }
+     write_byte(0xa000,addr,AL);
+     outw(VGAREG_GRDC_ADDRESS, 0xff08);
+     outw(VGAREG_GRDC_ADDRESS, 0x0005);
+     outw(VGAREG_GRDC_ADDRESS, 0x0003);
+     break;
+   case CGA:
+     if(vga_modes[line].pixbits==2)
+      {
+       addr=(CX>>2)+(DX>>1)*80;
+      }
+     else
+      {
+       addr=(CX>>3)+(DX>>1)*80;
+      }
+     if (DX & 1) addr += 0x2000;
+     data = read_byte(0xb800,addr);
+     if(vga_modes[line].pixbits==2)
+      {
+       attr = (AL & 0x03) << ((3 - (CX & 0x03)) * 2);
+       mask = 0x03 << ((3 - (CX & 0x03)) * 2);
+      }
+     else
+      {
+       attr = (AL & 0x01) << (7 - (CX & 0x07));
+       mask = 0x01 << (7 - (CX & 0x07));
+      }
+     if (AL & 0x80)
+      {
+       data ^= attr;
+      }
+     else
+      {
+       data &= ~mask;
+       data |= attr;
+      }
+     write_byte(0xb800,addr,data);
+     break;
+   case LINEAR8:
+     addr=CX+DX*(read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS)*8);
+     write_byte(0xa000,addr,AL);
+     break;
+#ifdef VGA_DEBUG
+   default:
+     unimplemented();
+#endif
+  }
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_write_teletype(uint8_t car, uint8_t page, uint8_t attr, uint8_t flag)
+{// flag = WITH_ATTR / NO_ATTR
+
+ uint8_t cheight,xcurs,ycurs,mode,line,bpp;
+ uint16_t nbcols,nbrows,address;
+ uint16_t cursor,dummy;
+
+ // special case if page is 0xff, use current page
+ if(page==0xff)
+  page=read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE);
+
+ // Get the mode
+ mode=read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE);
+ line=find_vga_entry(mode);
+ if(line==0xFF)return;
+
+ // Get the cursor pos for the page
+ vga_get_cursor_pos(page,&dummy,&cursor);
+ xcurs=cursor&0x00ff;ycurs=(cursor&0xff00)>>8;
+
+ // Get the dimensions
+ nbrows=read_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS)+1;
+ nbcols=read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS);
+
+ switch(car)
+  {
+   case '\a':   // ASCII 0x07, BEL
+    //FIXME should beep
+    break;
+
+   case '\b':   // ASCII 0x08, BS
+    if(xcurs>0)xcurs--;
+    break;
+
+   case '\n':   // ASCII 0x0A, LF
+    ycurs++;
+    break;
+
+   case '\r':   // ASCII 0x0D, CR
+    xcurs=0;
+    break;
+
+   default:
+
+    if(vga_modes[line].class==TEXT)
+     {
+      // Compute the address
+      address=SCREEN_MEM_START(nbcols,nbrows,page)+(xcurs+ycurs*nbcols)*2;
+
+      // Write the char
+      write_byte(vga_modes[line].sstart,address,car);
+
+      if(flag==WITH_ATTR)
+       write_byte(vga_modes[line].sstart,address+1,attr);
+     }
+    else
+     {
+      // FIXME gfx mode not complete
+      cheight=video_param_table[line_to_vpti[line]].cheight;
+      bpp=vga_modes[line].pixbits;
+      switch(vga_modes[line].memmodel)
+       {
+        case PLANAR1:
+          attr |= 0x01;  /* Color is ignored in 1bpp modes, always foreground. */
+        case PLANAR4:
+          write_gfx_char_pl4(car,attr,xcurs,ycurs,nbcols,cheight,page);
+          break;
+        case CGA:
+          write_gfx_char_cga(car,attr,xcurs,ycurs,nbcols,bpp);
+          break;
+        case LINEAR8:
+          write_gfx_char_lin(car,attr,xcurs,ycurs,nbcols);
+          break;
+#ifdef VGA_DEBUG
+        default:
+          unimplemented();
+#endif
+       }
+     }
+    xcurs++;
+    // Do we need to wrap ?
+    if(xcurs==nbcols)
+     {xcurs=0;
+      ycurs++;
+     }
+  }
+
+ // Do we need to scroll ?
+ if(ycurs==nbrows)
+  {
+   if(vga_modes[line].class==TEXT)
+    {
+     address=SCREEN_MEM_START(nbcols,nbrows,page)+(xcurs+(ycurs-1)*nbcols)*2;
+     attr=read_byte(vga_modes[line].sstart,address+1);
+     biosfn_scroll(0x01,attr,0,0,nbrows-1,nbcols-1,page,SCROLL_UP);
+    }
+   else
+    {
+     biosfn_scroll(0x01,0x00,0,0,nbrows-1,nbcols-1,page,SCROLL_UP);
+    }
+   ycurs-=1;
+  }
+
+ // Set the cursor for the page
+ cursor=ycurs; cursor<<=8; cursor+=xcurs;
+ biosfn_set_cursor_pos(page,cursor);
+}
+
+// --------------------------------------------------------------------------------------------
+static void get_font_access(void)
+{
+    outw(VGAREG_GRDC_ADDRESS, 0x0005);
+    outb(VGAREG_GRDC_ADDRESS, 0x06);
+    outw(VGAREG_GRDC_ADDRESS, (((0x04 | (inb(VGAREG_GRDC_DATA) & 0x01)) << 8) | 0x06));
+    outw(VGAREG_SEQU_ADDRESS, 0x0402);
+    outw(VGAREG_SEQU_ADDRESS, 0x0604);
+}
+
+static void release_font_access(void)
+{
+    outw(VGAREG_GRDC_ADDRESS, (((0x0a | ((inb(VGAREG_READ_MISC_OUTPUT) & 0x01) << 2)) << 8) | 0x06));
+    outw(VGAREG_GRDC_ADDRESS, 0x1005);
+    outw(VGAREG_SEQU_ADDRESS, 0x0302);
+    outw(VGAREG_SEQU_ADDRESS, 0x0204);
+}
+
+static void set_scan_lines(uint8_t lines)
+{
+ uint16_t crtc_addr,cols,vde;
+ uint8_t crtc_r9,ovl,rows;
+
+ crtc_addr = read_word(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS);
+ outb(crtc_addr, 0x09);
+ crtc_r9 = inb(crtc_addr+1);
+ crtc_r9 = (crtc_r9 & 0xe0) | (lines - 1);
+ outb(crtc_addr+1, crtc_r9);
+ if(lines==8)
+  {
+   biosfn_set_cursor_shape(0x06,0x07);
+  }
+ else
+  {
+   biosfn_set_cursor_shape(lines-4,lines-3);
+  }
+ write_word(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT, lines);
+ outb(crtc_addr, 0x12);
+ vde = inb(crtc_addr+1);
+ outb(crtc_addr, 0x07);
+ ovl = inb(crtc_addr+1);
+ vde += (((ovl & 0x02) << 7) + ((ovl & 0x40) << 3) + 1);
+ rows = vde / lines;
+ write_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS, rows-1);
+ cols = read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS);
+ write_word(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE, rows * cols * 2);
+}
+
+static void biosfn_set_font_block(uint8_t BL)
+{
+ outw(VGAREG_SEQU_ADDRESS, 0x0100);
+ outw(VGAREG_SEQU_ADDRESS, 0x0003 | (BL << 8));
+ outw(VGAREG_SEQU_ADDRESS, 0x0300);
+}
+
+static void load_text_patch(uint16_t ES, uint16_t BP, uint8_t BL, uint8_t BH)
+{
+    uint16_t   blockaddr, dest, src;
+    uint8_t    __far *pat;
+
+    get_font_access();
+
+    blockaddr = ((BL & 0x03) << 14) + ((BL & 0x04) << 11);
+    pat = ES :> (uint8_t *)BP;
+    src = BP + 1;
+    while (*pat) {
+        dest = blockaddr + *pat * 32;
+        memcpyb(0xA000, dest, ES, src, BH);
+        src += BH + 1;
+        pat += BH + 1;
+    }
+
+    release_font_access();
+}
+
+static void biosfn_load_text_user_pat(uint8_t AL, uint16_t ES, uint16_t BP, uint16_t CX,
+                                      uint16_t DX, uint8_t BL, uint8_t BH)
+{
+ uint16_t blockaddr,dest,i,src;
+
+ get_font_access();
+ blockaddr = ((BL & 0x03) << 14) + ((BL & 0x04) << 11);
+ for(i=0;i<CX;i++)
+  {
+   src = BP + i * BH;
+   dest = blockaddr + (DX + i) * 32;
+   memcpyb(0xA000, dest, ES, src, BH);
+  }
+ release_font_access();
+ if(AL>=0x10)
+  {
+   set_scan_lines(BH);
+  }
+}
+
+static void biosfn_load_gfx_8_8_chars(uint16_t ES, uint16_t BP)
+{
+    set_int_vector(0x1F, ES:>BP);
+}
+
+static void set_gfx_font(void _far *font, uint16_t cheight, uint8_t row_code, uint8_t rows)
+{
+    static  uint8_t row_tbl[] = { 0, 14, 25, 43 };
+
+    set_int_vector(0x43, font);
+    if (row_code) {
+        if (row_code > 3)
+            row_code = 2;   /* Default to 25 rows. */
+        rows = row_tbl[row_code];
+    }
+    /* Else 'rows' used as is. */
+
+    write_word(BIOSMEM_SEG, BIOSMEM_CHAR_HEIGHT, cheight);
+    write_word(BIOSMEM_SEG, BIOSMEM_NB_ROWS, rows - 1);
+}
+
+static void biosfn_load_gfx_user_chars(uint16_t ES, uint16_t BP, uint16_t CX,
+                                       uint8_t BL, uint8_t DL)
+{
+    set_gfx_font(ES:>BP, CX, BL, DL);
+}
+
+/* Some references (RBIL) suggest that only BL is used; that is wrong,
+ * all of these subfunctions will use DL if BL is zero.
+ */
+static void biosfn_load_gfx_8_14_chars(uint8_t BL, uint8_t DL)
+{
+    set_gfx_font(vgafont14, 14, BL, DL);
+}
+static void biosfn_load_gfx_8_8_dd_chars(uint8_t BL, uint8_t DL)
+{
+    set_gfx_font(vgafont8, 8, BL, DL);
+}
+static void biosfn_load_gfx_8_16_chars(uint8_t BL, uint8_t DL)
+{
+    set_gfx_font(vgafont16, 16, BL, DL);
+}
+// --------------------------------------------------------------------------------------------
+static void biosfn_alternate_prtsc(void)
+{
+#ifdef VGA_DEBUG
+ unimplemented();
+#endif
+}
+// --------------------------------------------------------------------------------------------
+static void biosfn_set_txt_lines(uint8_t AL)
+{
+    uint8_t     mctl;
+
+    /* Read byte at 40:89. */
+    mctl = read_byte(BIOSMEM_SEG, BIOSMEM_MODESET_CTL);
+    mctl = mctl & 0x6F; /* Clear 400/200 line flags. */
+
+    switch (AL) /* AL was already validated to be in 0-2 range. */
+    {
+    case 0: /* 200 lines. */
+        mctl |= 0x80;
+        break;
+    case 2: /* 400 lines. */
+        mctl |= 0x10;
+        break;
+    }
+    write_byte(BIOSMEM_SEG, BIOSMEM_MODESET_CTL, mctl);
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_switch_video_interface (AL,ES,DX) uint8_t AL;uint16_t ES;uint16_t DX;
+{
+#ifdef VGA_DEBUG
+ unimplemented();
+#endif
+}
+static void biosfn_enable_video_refresh_control(uint8_t AL)
+{
+#ifdef VGA_DEBUG
+ unimplemented();
+#endif
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_write_string(uint8_t flag, uint8_t page, uint8_t attr, uint16_t count,
+                                uint8_t row, uint8_t col, uint16_t seg, uint16_t offset)
+{
+ uint16_t newcurs,oldcurs,dummy;
+ uint8_t car;
+
+ // Read curs info for the page
+ vga_get_cursor_pos(page,&dummy,&oldcurs);
+
+ // if row=0xff special case : use current cursor position
+ if(row==0xff)
+  {col=oldcurs&0x00ff;
+   row=(oldcurs&0xff00)>>8;
+  }
+
+ newcurs=row; newcurs<<=8; newcurs+=col;
+ biosfn_set_cursor_pos(page,newcurs);
+
+ while(count--!=0)
+  {
+   car=read_byte(seg,offset++);
+   if((flag&0x02)!=0)
+    attr=read_byte(seg,offset++);
+
+   biosfn_write_teletype(car,page,attr,WITH_ATTR);
+  }
+
+ // Set back curs pos
+ if((flag&0x01)==0)
+  biosfn_set_cursor_pos(page,oldcurs);
+}
+
+// --------------------------------------------------------------------------------------------
+static void biosfn_read_state_info(uint16_t BX, uint16_t ES, uint16_t DI)
+{
+ uint16_t   pg_sz;
+ uint16_t   scans;
+ uint8_t    mode;
+ uint8_t    mctl;
+ uint8_t    temp;
+
+ mode  = read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE);
+ pg_sz = read_word(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE);
+ // Address of static functionality table
+ write_dword(ES,DI+0x00, (uint32_t)(void __far *)static_functionality);
+
+ // A lot is a straight copy from the BDA. Note that the number
+ // of character rows in the BDA is zero-based but one-based in
+ // the dynamic state area
+ memcpyb(ES,DI+0x04,BIOSMEM_SEG,BIOSMEM_CURRENT_MODE,30);
+ write_byte(ES,DI+0x22,read_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS)+1);
+ memcpyb(ES,DI+0x23,BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT,2);
+
+ write_byte(ES,DI+0x25,read_byte(BIOSMEM_SEG,BIOSMEM_DCC_INDEX));
+ write_byte(ES,DI+0x26,0);  // Alternate display code
+ write_word(ES,DI+0x27,16); // Number of colors
+ write_byte(ES,DI+0x29,8);  // Number of pages
+ write_byte(ES,DI+0x2a,2);  // Vertical resolution specifier
+ write_byte(ES,DI+0x2b,0);  // Primary font block
+ write_byte(ES,DI+0x2c,0);  // Secondary font block
+ write_byte(ES,DI+0x2d,0x21);
+ write_byte(ES,DI+0x31,3);  // 256K video RAM
+ write_byte(ES,DI+0x32,0);  // Save pointer state information
+
+ mctl = read_byte(BIOSMEM_SEG,BIOSMEM_MODESET_CTL);
+
+ /* Extract and write the vertical resolution specifier bits. */
+ scans = ((mctl & 0x80) >> 6) | ((mctl & 0x10) >> 4);
+ switch (scans) {
+ case 0:    temp = 1;   break;  /* 350 lines */
+ case 1:    temp = 2;   break;  /* 400 lines */
+ default:
+ case 2:    temp = 0;   break;  /* 200 lines */
+ }
+ write_byte(ES,DI+0x2a,temp);
+
+ /* Patch up the data for graphics modes. */
+ if (mode >= 0x0E && mode <= 0x12) {
+     if (pg_sz)
+         write_byte(ES,DI+0x29,16384/(pg_sz >> 2));
+ } else if (mode == 0x13) {
+     write_byte(ES,DI+0x29,1);      /* Just one page due to chaining */
+     write_word(ES,DI+0x27,256);    /* But 256!! colors!!! */
+ } else if (mode >= 4 && mode <= 6) {
+     /* CGA modes. */
+     if (pg_sz)
+         write_byte(ES,DI+0x29,16384/pg_sz);
+     write_word(ES,DI+0x27,4);
+ }
+ if (mode == 6 || mode == 0x11)
+     write_word(ES,DI+0x27,2);  /* 2-color modes. */
+
+ if ((mode >= 4) && (mode != 7)) {
+     write_byte(ES,DI+0x2d,0x01);
+     scans = (read_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS)+1) * read_byte(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT);
+     switch (scans) {
+     case 200:  temp = 0;   break;
+     case 350:  temp = 1;   break;
+     case 400:  temp = 2;   break;
+     default:
+     case 480:  temp = 3;   break;
+     }
+     write_byte(ES,DI+0x2a,temp);
+ }
+
+ memsetb(ES,DI+0x33,0,13);
+}
+
+// --------------------------------------------------------------------------------------------
+uint16_t biosfn_read_video_state_size2(uint16_t state)
+{
+    uint16_t    size;
+
+    size = 0;
+    if (state & 1)
+        size += 0x46;
+
+    if (state & 2)
+        size += (5 + 8 + 5) * 2 + 6;
+
+    if (state & 4)
+        size += 3 + 256 * 3 + 1;
+
+    return size;
+}
+
+static void vga_get_video_state_size(uint16_t state, uint16_t STACK_BASED *size)
+{
+    /* The size is the number of 64-byte blocks required to save the state. */
+    *size = (biosfn_read_video_state_size2(state) + 63) / 64;
+}
+
+uint16_t biosfn_save_video_state(uint16_t CX, uint16_t ES, uint16_t BX)
+{
+    uint16_t i, crtc_addr, ar_index;
+
+    crtc_addr = read_word(BIOSMEM_SEG, BIOSMEM_CRTC_ADDRESS);
+    if (CX & 1) {
+        write_byte(ES, BX, inb(VGAREG_SEQU_ADDRESS)); BX++;
+        write_byte(ES, BX, inb(crtc_addr)); BX++;
+        write_byte(ES, BX, inb(VGAREG_GRDC_ADDRESS)); BX++;
+        inb(VGAREG_ACTL_RESET);
+        ar_index = inb(VGAREG_ACTL_ADDRESS);
+        write_byte(ES, BX, ar_index); BX++;
+        write_byte(ES, BX, inb(VGAREG_READ_FEATURE_CTL)); BX++;
+
+        for(i=1;i<=4;i++){
+            outb(VGAREG_SEQU_ADDRESS, i);
+            write_byte(ES, BX, inb(VGAREG_SEQU_DATA)); BX++;
+        }
+        outb(VGAREG_SEQU_ADDRESS, 0);
+        write_byte(ES, BX, inb(VGAREG_SEQU_DATA)); BX++;
+
+        for(i=0;i<=0x18;i++) {
+            outb(crtc_addr,i);
+            write_byte(ES, BX, inb(crtc_addr+1)); BX++;
+        }
+
+        for(i=0;i<=0x13;i++) {
+            inb(VGAREG_ACTL_RESET); /* Reads do not toggle flip-flop! */
+            outb(VGAREG_ACTL_ADDRESS, i | (ar_index & 0x20));
+            write_byte(ES, BX, inb(VGAREG_ACTL_READ_DATA)); BX++;
+        }
+        inb(VGAREG_ACTL_RESET);
+
+        for(i=0;i<=8;i++) {
+            outb(VGAREG_GRDC_ADDRESS,i);
+            write_byte(ES, BX, inb(VGAREG_GRDC_DATA)); BX++;
+        }
+
+        write_word(ES, BX, crtc_addr); BX+= 2;
+
+        /* XXX: read plane latches */
+        write_byte(ES, BX, 0); BX++;
+        write_byte(ES, BX, 0); BX++;
+        write_byte(ES, BX, 0); BX++;
+        write_byte(ES, BX, 0); BX++;
+    }
+    if (CX & 2) {
+        write_byte(ES, BX, read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE)); BX++;
+        write_word(ES, BX, read_word(BIOSMEM_SEG,BIOSMEM_NB_COLS)); BX += 2;
+        write_word(ES, BX, read_word(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE)); BX += 2;
+        write_word(ES, BX, read_word(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS)); BX += 2;
+        write_byte(ES, BX, read_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS)); BX++;
+        write_word(ES, BX, read_word(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT)); BX += 2;
+        write_byte(ES, BX, read_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL)); BX++;
+        write_byte(ES, BX, read_byte(BIOSMEM_SEG,BIOSMEM_SWITCHES)); BX++;
+        write_byte(ES, BX, read_byte(BIOSMEM_SEG,BIOSMEM_MODESET_CTL)); BX++;
+        write_word(ES, BX, read_word(BIOSMEM_SEG,BIOSMEM_CURSOR_TYPE)); BX += 2;
+        for(i=0;i<8;i++) {
+            write_word(ES, BX, read_word(BIOSMEM_SEG, BIOSMEM_CURSOR_POS+2*i));
+            BX += 2;
+        }
+        write_word(ES, BX, read_word(BIOSMEM_SEG,BIOSMEM_CURRENT_START)); BX += 2;
+        write_byte(ES, BX, read_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE)); BX++;
+        /* current font */
+        write_word(ES, BX, read_word(0, 0x1f * 4)); BX += 2;
+        write_word(ES, BX, read_word(0, 0x1f * 4 + 2)); BX += 2;
+        write_word(ES, BX, read_word(0, 0x43 * 4)); BX += 2;
+        write_word(ES, BX, read_word(0, 0x43 * 4 + 2)); BX += 2;
+    }
+    if (CX & 4) {
+        /* XXX: check this */
+        write_byte(ES, BX, inb(VGAREG_DAC_STATE)); BX++; /* read/write mode dac */
+        write_byte(ES, BX, inb(VGAREG_DAC_WRITE_ADDRESS)); BX++; /* pix address */
+        write_byte(ES, BX, inb(VGAREG_PEL_MASK)); BX++;
+        // Set the whole dac always, from 0
+        outb(VGAREG_DAC_WRITE_ADDRESS,0x00);
+        for(i=0;i<256*3;i++) {
+            write_byte(ES, BX, inb(VGAREG_DAC_DATA)); BX++;
+        }
+        write_byte(ES, BX, 0); BX++; /* color select register */
+    }
+    return BX;
+}
+
+uint16_t biosfn_restore_video_state(uint16_t CX, uint16_t ES, uint16_t BX)
+{
+    uint16_t i, crtc_addr, v, addr1, ar_index;
+
+    if (CX & 1) {
+        // Reset Attribute Ctl flip-flop
+        inb(VGAREG_ACTL_RESET);
+
+        crtc_addr = read_word(ES, BX + 0x40);
+        addr1 = BX;
+        BX += 5;
+
+        for(i=1;i<=4;i++){
+            outb(VGAREG_SEQU_ADDRESS, i);
+            outb(VGAREG_SEQU_DATA, read_byte(ES, BX)); BX++;
+        }
+        outb(VGAREG_SEQU_ADDRESS, 0);
+        outb(VGAREG_SEQU_DATA, read_byte(ES, BX)); BX++;
+
+        // select crtc base address
+        v = inb(VGAREG_READ_MISC_OUTPUT) & ~0x01;
+        if (crtc_addr == 0x3d4)
+            v |= 0x01;
+        outb(VGAREG_WRITE_MISC_OUTPUT, v);
+
+        // Disable CRTC write protection
+        outw(crtc_addr,0x0011);
+        // Set CRTC regs
+        for(i=0;i<=0x18;i++) {
+            if (i != 0x11) {
+                outb(crtc_addr,i);
+                outb(crtc_addr+1, read_byte(ES, BX));
+            }
+            BX++;
+        }
+        // enable write protection if needed
+        outb(crtc_addr, 0x11);
+        outb(crtc_addr+1, read_byte(ES, BX - 0x18 + 0x11));
+
+        // Set Attribute Ctl
+        ar_index = read_byte(ES, addr1 + 0x03);
+        inb(VGAREG_ACTL_RESET);
+        for(i=0;i<=0x13;i++) {
+            outb(VGAREG_ACTL_ADDRESS, i | (ar_index & 0x20));
+            outb(VGAREG_ACTL_WRITE_DATA, read_byte(ES, BX)); BX++;
+        }
+        outb(VGAREG_ACTL_ADDRESS, ar_index);
+        inb(VGAREG_ACTL_RESET);
+
+        for(i=0;i<=8;i++) {
+            outb(VGAREG_GRDC_ADDRESS,i);
+            outb(VGAREG_GRDC_DATA, read_byte(ES, BX)); BX++;
+        }
+        BX += 2; /* crtc_addr */
+        BX += 4; /* plane latches */
+
+        outb(VGAREG_SEQU_ADDRESS, read_byte(ES, addr1)); addr1++;
+        outb(crtc_addr, read_byte(ES, addr1)); addr1++;
+        outb(VGAREG_GRDC_ADDRESS, read_byte(ES, addr1)); addr1++;
+        addr1++;
+        outb(crtc_addr - 0x4 + 0xa, read_byte(ES, addr1)); addr1++;
+    }
+    if (CX & 2) {
+        write_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_MODE, read_byte(ES, BX)); BX++;
+        write_word(BIOSMEM_SEG,BIOSMEM_NB_COLS, read_word(ES, BX)); BX += 2;
+        write_word(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE, read_word(ES, BX)); BX += 2;
+        write_word(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS, read_word(ES, BX)); BX += 2;
+        write_byte(BIOSMEM_SEG,BIOSMEM_NB_ROWS, read_byte(ES, BX)); BX++;
+        write_word(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT, read_word(ES, BX)); BX += 2;
+        write_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL, read_byte(ES, BX)); BX++;
+        write_byte(BIOSMEM_SEG,BIOSMEM_SWITCHES, read_byte(ES, BX)); BX++;
+        write_byte(BIOSMEM_SEG,BIOSMEM_MODESET_CTL, read_byte(ES, BX)); BX++;
+        write_word(BIOSMEM_SEG,BIOSMEM_CURSOR_TYPE, read_word(ES, BX)); BX += 2;
+        for(i=0;i<8;i++) {
+            write_word(BIOSMEM_SEG, BIOSMEM_CURSOR_POS+2*i, read_word(ES, BX));
+            BX += 2;
+        }
+        write_word(BIOSMEM_SEG,BIOSMEM_CURRENT_START, read_word(ES, BX)); BX += 2;
+        write_byte(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE, read_byte(ES, BX)); BX++;
+        /* current font */
+        write_word(0, 0x1f * 4, read_word(ES, BX)); BX += 2;
+        write_word(0, 0x1f * 4 + 2, read_word(ES, BX)); BX += 2;
+        write_word(0, 0x43 * 4, read_word(ES, BX)); BX += 2;
+        write_word(0, 0x43 * 4 + 2, read_word(ES, BX)); BX += 2;
+    }
+    if (CX & 4) {
+        BX++;
+        v = read_byte(ES, BX); BX++;
+        outb(VGAREG_PEL_MASK, read_byte(ES, BX)); BX++;
+        // Set the whole dac always, from 0
+        outb(VGAREG_DAC_WRITE_ADDRESS,0x00);
+        for(i=0;i<256*3;i++) {
+            outb(VGAREG_DAC_DATA, read_byte(ES, BX)); BX++;
+        }
+        BX++;
+        outb(VGAREG_DAC_WRITE_ADDRESS, v);
+    }
+    return BX;
+}
+
+// ============================================================================================
+//
+// Video Utils
+//
+// ============================================================================================
+
+// --------------------------------------------------------------------------------------------
+static uint8_t find_vga_entry(uint8_t mode)
+{
+ uint8_t i,line=0xFF;
+ for(i=0;i<=MODE_MAX;i++)
+  if(vga_modes[i].svgamode==mode)
+   {line=i;
+    break;
+   }
+ return line;
+}
+
+/* =========================================================== */
+/*
+ * Misc Utils
+*/
+/* =========================================================== */
+
+/* This function is used for planar VGA memory reads to defeat the
+ * optimizer. We must read exactly one byte, otherwise the screen
+ * may be corrupted.
+ */
+uint8_t readx_byte(uint16_t seg, uint16_t offset)
+{
+    return( *(seg:>(uint8_t *)offset) );
+}
+
+#ifdef VGA_DEBUG
+void __cdecl unimplemented()
+{
+ printf("--> Unimplemented\n");
+}
+
+void __cdecl unknown()
+{
+ printf("--> Unknown int10\n");
+}
+
+#undef VBE_PRINTF_PORT
+#define VBE_PRINTF_PORT 0x504
+
+// --------------------------------------------------------------------------------------------
+void __cdecl printf(char *s, ...)
+{
+    char        c;
+    Boolean     in_format;
+    unsigned    format_width, i;
+    uint16_t    arg, digit, nibble;
+    uint16_t STACK_BASED *arg_ptr;
+
+    arg_ptr = (uint16_t STACK_BASED *)&s;
+
+    in_format    = 0;
+    format_width = 0;
+
+    while (c = *s) {
+        if (c == '%') {
+            in_format    = 1;
+            format_width = 0;
+        } else if (in_format) {
+            if ((c >= '0') && (c <= '9')) {
+                format_width = (format_width * 10) + (c - '0');
+            } else if (c == 'x') {
+                arg_ptr++; // increment to next arg
+                arg = *arg_ptr;
+                if (format_width == 0)
+                    format_width = 4;
+                i = 0;
+                digit = format_width - 1;
+                for (i = 0; i < format_width; i++) {
+                    nibble = (arg >> (4 * digit)) & 0x000f;
+                    if (nibble <= 9)
+                        outb(VBE_PRINTF_PORT, nibble + '0');
+                    else
+                        outb(VBE_PRINTF_PORT, (nibble - 10) + 'A');
+                    digit--;
+                }
+                in_format = 0;
+            }
+            //else if (c == 'd') {
+            //  in_format = 0;
+            //  }
+        } else {
+            outb(VBE_PRINTF_PORT, c);
+        }
+        ++s;
+    }
+}
+#endif
+
+/// @todo rearrange, call only from VBE module?
+extern void vbe_biosfn_return_controller_information(uint16_t STACK_BASED *AX, uint16_t ES, uint16_t DI);
+extern void vbe_biosfn_return_mode_information(uint16_t STACK_BASED *AX, uint16_t CX, uint16_t ES, uint16_t DI);
+extern void vbe_biosfn_set_mode(uint16_t STACK_BASED *AX, uint16_t BX, uint16_t ES, uint16_t DI);
+extern void vbe_biosfn_save_restore_state(uint16_t STACK_BASED *AX, uint16_t CX, uint16_t DX, uint16_t ES, uint16_t STACK_BASED *BX);
+extern void vbe_biosfn_get_set_scanline_length(uint16_t STACK_BASED *AX, uint16_t STACK_BASED *BX, uint16_t STACK_BASED *CX, uint16_t STACK_BASED *DX);
+extern void private_biosfn_custom_mode(uint16_t STACK_BASED *AX, uint16_t STACK_BASED *BX, uint16_t STACK_BASED *CX, uint16_t STACK_BASED *DX);
+
+
+// --------------------------------------------------------------------------------------------
+/*
+ * int10 main dispatcher
+ */
+void __cdecl int10_func(uint16_t DI, uint16_t SI, uint16_t BP, uint16_t SP, uint16_t BX,
+                        uint16_t DX, uint16_t CX, uint16_t AX, uint16_t DS, uint16_t ES, uint16_t FLAGS)
+{
+
+ // BIOS functions
+ switch(GET_AH())
+  {
+   case 0x00:
+     biosfn_set_video_mode(GET_AL());
+     switch(GET_AL()&0x7F)
+      {case 6:
+        SET_AL(0x3F);
+        break;
+       case 0:
+       case 1:
+       case 2:
+       case 3:
+       case 4:
+       case 5:
+       case 7:
+        SET_AL(0x30);
+        break;
+      default:
+        SET_AL(0x20);
+      }
+     break;
+   case 0x01:
+     biosfn_set_cursor_shape(GET_CH(),GET_CL());
+     break;
+   case 0x02:
+     biosfn_set_cursor_pos(GET_BH(),DX);
+     break;
+   case 0x03:
+     vga_get_cursor_pos(GET_BH(), &CX, &DX);
+     break;
+   case 0x04:
+     // Read light pen pos (unimplemented)
+#ifdef VGA_DEBUG
+     unimplemented();
+#endif
+     AX=0x00;
+     BX=0x00;
+     CX=0x00;
+     DX=0x00;
+     break;
+   case 0x05:
+     biosfn_set_active_page(GET_AL());
+     break;
+   case 0x06:
+     biosfn_scroll(GET_AL(),GET_BH(),GET_CH(),GET_CL(),GET_DH(),GET_DL(),0xFF,SCROLL_UP);
+     break;
+   case 0x07:
+     biosfn_scroll(GET_AL(),GET_BH(),GET_CH(),GET_CL(),GET_DH(),GET_DL(),0xFF,SCROLL_DOWN);
+     break;
+   case 0x08:
+     vga_read_char_attr(GET_BH(), &AX);
+     break;
+   case 0x09:
+     biosfn_write_char_attr(GET_AL(),GET_BH(),GET_BL(),CX);
+     break;
+   case 0x0A:
+     biosfn_write_char_only(GET_AL(),GET_BH(),GET_BL(),CX);
+     break;
+   case 0x0C:
+     biosfn_write_pixel(GET_BH(),GET_AL(),CX,DX);
+     break;
+   case 0x0D:
+     vga_read_pixel(GET_BH(), CX, DX, &AX);
+     break;
+   case 0x0E:
+     // Ralf Brown Interrupt list is WRONG on bh(page)
+     // We do output only on the current page !
+#ifdef VGA_DEBUG
+     printf("write_teletype %02x\n", GET_AL());
+#endif
+
+     biosfn_write_teletype(GET_AL(),0xff,GET_BL(),NO_ATTR);
+     break;
+   case 0x10:
+     // All other functions of group AH=0x10 rewritten in assembler
+     biosfn_perform_gray_scale_summing(BX,CX);
+     break;
+   case 0x11:
+     switch(GET_AL())
+      {
+       case 0x00:
+       case 0x10:
+        biosfn_load_text_user_pat(GET_AL(),ES,BP,CX,DX,GET_BL(),GET_BH());
+        break;
+       case 0x01:
+       case 0x11:
+        biosfn_load_text_user_pat(GET_AL(), 0xC000, (uint16_t)vgafont14,  256, 0, GET_BL(), 14);
+        break;
+       case 0x02:
+       case 0x12:
+        biosfn_load_text_user_pat(GET_AL(), 0xC000, (uint16_t)vgafont8,  256, 0, GET_BL(), 8);
+        break;
+       case 0x03:
+        biosfn_set_font_block(GET_BL());
+        break;
+       case 0x04:
+       case 0x14:
+        biosfn_load_text_user_pat(GET_AL(), 0xC000, (uint16_t)vgafont16,  256, 0, GET_BL(), 16);
+        break;
+       case 0x20:
+        biosfn_load_gfx_8_8_chars(ES,BP);
+        break;
+       case 0x21:
+        biosfn_load_gfx_user_chars(ES,BP,CX,GET_BL(),GET_DL());
+        break;
+       case 0x22:
+        biosfn_load_gfx_8_14_chars(GET_BL(),GET_DL());
+        break;
+       case 0x23:
+        biosfn_load_gfx_8_8_dd_chars(GET_BL(),GET_DL());
+        break;
+       case 0x24:
+        biosfn_load_gfx_8_16_chars(GET_BL(),GET_DL());
+        break;
+       case 0x30:
+        vga_get_font_info(GET_BH(), &ES, &BP, &CX, &DX);
+        break;
+#ifdef VGA_DEBUG
+       default:
+        unknown();
+#endif
+      }
+
+     break;
+   case 0x12:
+     switch(GET_BL())
+      {
+       case 0x20:
+        biosfn_alternate_prtsc();
+        break;
+       case 0x30:
+         if (GET_AL() <= 2) {
+             biosfn_set_txt_lines(GET_AL());
+             SET_AL(0x12);
+         }
+         break;
+       case 0x34:   /* CGA text cursor emulation control. */
+        if (GET_AL() < 2) {
+            write_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL,
+              (read_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL) & ~1) | GET_AL());
+            SET_AL(0x12);
+        }
+        else
+         SET_AL(0); /* Invalid argument. */
+        break;
+       case 0x35:
+        biosfn_switch_video_interface(GET_AL(),ES,DX);
+        SET_AL(0x12);
+        break;
+       case 0x36:
+        biosfn_enable_video_refresh_control(GET_AL());
+        SET_AL(0x12);
+        break;
+#ifdef VGA_DEBUG
+       default:
+        unknown();
+#endif
+      }
+     break;
+   case 0x13:
+     biosfn_write_string(GET_AL(),GET_BH(),GET_BL(),CX,GET_DH(),GET_DL(),ES,BP);
+     break;
+   case 0x1B:
+     biosfn_read_state_info(BX,ES,DI);
+     SET_AL(0x1B);
+     break;
+   case 0x1C:
+     switch(GET_AL())
+      {
+       case 0x00:
+        vga_get_video_state_size(CX,&BX);
+        break;
+       case 0x01:
+        biosfn_save_video_state(CX,ES,BX);
+        break;
+       case 0x02:
+        biosfn_restore_video_state(CX,ES,BX);
+        break;
+#ifdef VGA_DEBUG
+       default:
+        unknown();
+#endif
+      }
+     SET_AL(0x1C);
+     break;
+
+#ifdef VBE
+   case 0x4f:
+     if (vbe_has_vbe_display()) {
+       switch(GET_AL())
+       {
+         case 0x00:
+          vbe_biosfn_return_controller_information(&AX,ES,DI);
+          break;
+         case 0x01:
+          vbe_biosfn_return_mode_information(&AX,CX,ES,DI);
+          break;
+         case 0x02:
+          vbe_biosfn_set_mode(&AX,BX,ES,DI);
+          break;
+         case 0x04:
+          vbe_biosfn_save_restore_state(&AX, CX, DX, ES, &BX);
+          break;
+         case 0x06:
+          vbe_biosfn_get_set_scanline_length(&AX, &BX, &CX, &DX);
+          break;
+         case 0x09:
+          //FIXME
+#ifdef VGA_DEBUG
+          unimplemented();
+#endif
+          // function failed
+          AX=0x100;
+          break;
+         case 0x0A:
+          //FIXME
+#ifdef VGA_DEBUG
+          unimplemented();
+#endif
+          // function failed
+          AX=0x100;
+          break;
+         default:
+#ifdef VGA_DEBUG
+          unknown();
+#endif
+          // function failed
+          AX=0x100;
+          }
+        }
+        else {
+          // No VBE display
+          AX=0x0100;
+          }
+        break;
+   case 0x56:
+     if (vbe_has_vbe_display()) {
+       switch(GET_AL())
+       {
+         case 0x42:
+           private_biosfn_custom_mode(&AX,&BX,&CX,&DX);
+           break;
+         default:
+           AX=0x0100;
+           break;
+       }
+     } else {
+         // No VBE display
+         AX=0x0100;
+     }
+     break;
+#endif
+
+#ifdef VGA_DEBUG
+   default:
+     unknown();
+#endif
+  }
+}
+
+#ifdef VBE
+//#include "vbe.c"
+#endif
+
+#ifdef CIRRUS
+#include "clext.c"
+#endif
+
+// --------------------------------------------------------------------------------------------
+