static void TANDY_FindMode(void) {
if (vga.tandy.mode_control & 0x2) {
if (vga.tandy.gfx_control & 0x10) VGA_SetMode(M_TANDY16);
else if (vga.tandy.gfx_control & 0x08) VGA_SetMode(M_TANDY4);
else if (vga.tandy.mode_control & 0x10) VGA_SetMode(M_TANDY2);
else VGA_SetMode(M_TANDY4);
write_color_select(vga.tandy.color_select);
} else {
VGA_SetMode(M_TANDY_TEXT);
}
}
static void write_mode_control(Bit8u val) {
/* Check if someone changes the blinking/hi intensity bit */
vga.tandy.mode_control=val;
VGA_SetBlinking((val & 0x20));
if (val & 0x2) {
if (val & 0x10) {
} else VGA_SetMode(M_CGA4);
write_color_select(vga.tandy.color_select); //Setup the correct palette
} else {
VGA_SetMode(M_TEXT);
}
}
void DetermineMode_PVGA1A() {
// Close replica from the base implementation. It will stay here
// until I figure a way to either distinguish M_VGA and M_LIN8 or
// merge them.
if (vga.attr.mode_control & 1) {
if (vga.gfx.mode & 0x40) VGA_SetMode((pvga1a.biosMode<=0x13)?M_VGA:M_LIN8);
else if (vga.gfx.mode & 0x20) VGA_SetMode(M_CGA4);
else if ((vga.gfx.miscellaneous & 0x0c)==0x0c) VGA_SetMode(M_CGA2);
else VGA_SetMode((pvga1a.biosMode<=0x13)?M_EGA:M_LIN4);
} else {
VGA_SetMode(M_TEXT);
}
}
static void PCJr_FindMode(void) {
if (vga.tandy.mode_control & 0x2) {
if (vga.tandy.mode_control & 0x10) {
/* bit4 of mode control 1 signals 16 colour graphics mode */
VGA_SetMode(M_TANDY16);
} else if (vga.tandy.gfx_control & 0x08) {
/* bit3 of mode control 2 signals 2 colour graphics mode */
VGA_SetMode(M_TANDY2);
} else {
/* otherwise some 4-colour graphics mode */
VGA_SetMode(M_TANDY4);
}
write_color_select(vga.tandy.color_select);
} else {
VGA_SetMode(M_TANDY_TEXT);
}
}
static void write_hercules(Bitu port,Bitu val,Bitu iolen) {
switch (port) {
case 0x3b8: {
// the protected bits can always be cleared but only be set if the
// protection bits are set
if (vga.herc.mode_control&0x2) {
// already set
if (!(val&0x2)) {
vga.herc.mode_control &= ~0x2;
VGA_SetMode(M_HERC_TEXT);
}
} else {
// not set, can only set if protection bit is set
if ((val & 0x2) && (vga.herc.enable_bits & 0x1)) {
vga.herc.mode_control |= 0x2;
VGA_SetMode(M_HERC_GFX);
}
}
if (vga.herc.mode_control&0x80) {
if (!(val&0x80)) {
vga.herc.mode_control &= ~0x80;
vga.tandy.draw_base = &vga.mem.linear[0];
}
} else {
if ((val & 0x80) && (vga.herc.enable_bits & 0x2)) {
vga.herc.mode_control |= 0x80;
vga.tandy.draw_base = &vga.mem.linear[32*1024];
}
}
vga.draw.blinking = (val&0x20)!=0;
vga.herc.mode_control &= 0x82;
vga.herc.mode_control |= val & ~0x82;
break;
}
case 0x3bf:
vga.herc.enable_bits=val;
break;
}
}
static void write_hercules(Bitu port,Bitu val,Bitu iolen) {
switch (port) {
case 0x3b8:
if (vga.herc.enable_bits & 1) {
vga.herc.mode_control&=~0x2;
vga.herc.mode_control|=(val&0x2);
if (val & 0x2) {
VGA_SetMode(M_HERC_GFX);
} else {
VGA_SetMode(M_HERC_TEXT);
}
}
if ((vga.herc.enable_bits & 0x2) && ((vga.herc.mode_control ^ val)&0x80)) {
vga.herc.mode_control^=0x80;
VGA_SetupHandlers();
}
break;
case 0x3bf:
vga.herc.enable_bits=val;
break;
}
}
static void write_cga(Bitu port,Bitu val,Bitu iolen) {
switch (port) {
case 0x3d8:
vga.tandy.mode_control=val;
if (vga.tandy.mode_control & 0x2) {
if (vga.tandy.mode_control & 0x10) {
if (!(val & 0x4) && machine==MCH_CGA) {
VGA_SetMode(M_CGA16); //Video burst 16 160x200 color mode
} else {
VGA_SetMode(M_TANDY2);
}
} else VGA_SetMode(M_TANDY4);
write_color_select(vga.tandy.color_select);
} else {
VGA_SetMode(M_TANDY_TEXT);
}
VGA_SetBlinking(val & 0x20);
break;
case 0x3d9:
write_color_select(val);
break;
}
}
static WORD DISPDIB_Begin(WORD wFlags)
{
unsigned Xres,Yres,Depth;
switch(wFlags&DISPLAYDIB_MODE) {
case DISPLAYDIB_MODE_DEFAULT:
/* FIXME: is this supposed to autodetect? */
case DISPLAYDIB_MODE_320x200x8:
Xres=320; Yres=200; Depth=8; break;
case DISPLAYDIB_MODE_320x240x8:
Xres=320; Yres=240; Depth=8; break;
default:
return DISPLAYDIB_NOTSUPPORTED;
}
/* more or less dummy calls to Death/Resurrection, for completeness */
/* FIXME: what arguments should they get? */
Death16(0);
if (VGA_SetMode(Xres,Yres,Depth)) {
Resurrection16(0,0,0,0,0,0,0);
return DISPLAYDIB_NOTSUPPORTED;
}
return DISPLAYDIB_NOERROR;
}
/**********************************************************************
* INT10_SetVideoMode
*
* Change current video mode to any VGA or VESA mode.
* Returns TRUE if mode is supported.
*
* Mode bitfields:
* 0-6: .. Mode number (combined with bit 8).
* 7: =0 Clear screen.
* =1 Preserve display memory on mode change (VGA modes).
* 8: =0 VGA mode.
* =1 VESA mode.
* 9: .. Reserved, must be zero.
* 10: .. Reserved, must be zero.
* 11: =0 Use default refresh rate.
* =1 Use user specified refresh rate.
* 12: .. Reserved, must be zero.
* 13: .. Reserved, must be zero.
* 14: =0 Use windowed frame buffer model.
* =1 Use linear frame buffer model.
* 15: =0 Clear screen.
* =1 Preserve display memory on mode change (VESA modes).
*/
static BOOL INT10_SetVideoMode( BIOSDATA *data, WORD mode )
{
const VGA_MODE *ptr = VGA_GetModeInfo( mode );
INT10_HEAP *heap = INT10_GetHeap();
BOOL clearScreen = TRUE;
if (!ptr)
return FALSE;
/*
* Linear framebuffer is not supported.
* FIXME - not sure this is valid since mode 19 is 256 color & linear
* of course only 1 window is addressable.
*/
if (mode & 0x4000)
return FALSE;
/*
* Check for VGA and VESA preserve video memory flag.
*/
if ((mode & 0x0080) || (mode & 0x8000))
clearScreen = FALSE;
/*
* Note that we do not mask out flags here on purpose.
*/
heap->VesaCurrentMode = mode;
if (mode <= 0xff)
data->VideoMode = mode;
else
data->VideoMode = 0;
if (ptr->ModeType == TEXT)
{
/* Text mode. */
TRACE( "Setting %s %dx%d text mode (screen %s)\n",
IS_VESA_MODE(mode) ? "VESA" : "VGA",
ptr->TextCols, ptr->TextRows,
clearScreen ? "cleared" : "preserved" );
/*
* FIXME: We should check here if alpha mode could be set.
*/
VGA_SetAlphaMode( ptr->TextCols, ptr->TextRows );
data->VideoColumns = ptr->TextCols;
data->RowsOnScreenMinus1 = ptr->TextRows - 1;
if (clearScreen)
{
VGA_ClearText( 0, 0, ptr->TextCols-1, ptr->TextRows-1, 0x07 );
INT10_SetCursorPos( data, 0, 0, 0 );
VGA_SetCursorPos( 0, 0 );
}
}
else
{
/* Graphics mode. */
TRACE( "Setting %s %dx%dx%d graphics mode (screen %s)\n",
IS_VESA_MODE(mode) ? "VESA" : "VGA",
ptr->Width, ptr->Height, ptr->Depth,
clearScreen ? "cleared" : "preserved" );
if ( VGA_SetMode(mode) )
return FALSE;
}
return TRUE;
}