Sprinter/mame
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

i8275: Added character attributes and special character codes. [Curt Coder]

Browse Source
This commit is contained in:
Curt Coder 2014-04-30 12:50:55 +00:00
parent 163f4c6cde
commit 37f1d95c3e
2 changed files with 108 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

96
src/emu/video/i8275.c
View File

@ -13,7 +13,6 @@
TODO:
- character attributes
- double spaced rows
*/
@ -69,6 +68,14 @@ const int DMA_BURST_SPACING[] = { 0, 7, 15, 23, 31, 39, 47, 55 };
DMA_BURST_SPACING[(m_param[REG_DMA] >> 2) & 0x07]
const int i8275_device::character_attribute[3][16] =
{
{ 2, 2, 4, 4, 2, 4, 4, 4, 2, 4, 4, 0, 2, 0, 0, 0 },
{ 8, 0xc, 8, 0xc, 1, 0xc, 8, 1, 1, 4, 1, 0, 2, 0, 0, 0 },
{ 4, 4, 2, 2, 4, 4, 4, 2, 2, 4, 4, 0, 2, 0, 0, 0 }
};
//**************************************************************************
// DEVICE DEFINITIONS
@ -108,6 +115,7 @@ i8275_device::i8275_device(const machine_config &mconfig, const char *tag, devic
m_lten(0),
m_scanline(0),
m_du(false),
m_end_of_screen(false),
m_cursor_blink(0),
m_char_blink(0)
{
@ -220,6 +228,8 @@ void i8275_device::device_timer(emu_timer &timer, device_timer_id id, int param,
m_lten = 0;
m_du = false;
m_dma_stop = false;
m_end_of_screen = false;
m_cursor_blink++;
m_cursor_blink &= 0x1f;
@ -243,7 +253,7 @@ void i8275_device::device_timer(emu_timer &timer, device_timer_id id, int param,
m_buffer_idx = 0;
m_fifo_idx = 0;
if ((!m_du && (m_scanline < m_vrtc_scanline - SCANLINES_PER_ROW)) || (m_scanline == m_vrtc_drq_scanline))
if ((!m_dma_stop && !m_du && (m_scanline < m_vrtc_scanline - SCANLINES_PER_ROW)) || (m_scanline == m_vrtc_drq_scanline))
{
// start DMA burst
m_drq_on_timer->adjust(clocks_to_attotime(DMA_BURST_SPACE));
@ -253,6 +263,7 @@ void i8275_device::device_timer(emu_timer &timer, device_timer_id id, int param,
if (m_scanline < m_vrtc_scanline)
{
int line_counter = OFFSET_LINE_COUNTER ? ((lc - 1) % SCANLINES_PER_ROW) : lc;
bool end_of_row = false;
for (int sx = 0; sx < CHARACTERS_PER_ROW; sx++)
{
@ -289,7 +300,48 @@ void i8275_device::device_timer(emu_timer &timer, device_timer_id id, int param,
}
else
{
// character attribute code
if ((data & 0xf0) == 0xf0)
{
// special control character
switch (data)
{
case SCC_END_OF_ROW:
case SCC_END_OF_ROW_DMA:
end_of_row = true;
break;
case SCC_END_OF_SCREEN:
case SCC_END_OF_SCREEN_DMA:
m_end_of_screen = true;
break;
}
}
else
{
// character attribute code
m_hlgt = (data & CA_H) ? 1 : 0;
m_vsp = (data & CA_B) ? 1 : 0;
UINT8 ca = 0;
int cccc = (data >> 2) & 0x0f;
if (line_counter < UNDERLINE)
{
ca = character_attribute[0][cccc];
}
else if (line_counter == UNDERLINE)
{
ca = character_attribute[1][cccc];
}
else
{
ca = character_attribute[2][cccc];
}
m_lten = (ca & CA_LTEN) ? 1 : 0;
m_vsp = (ca & CA_VSP) ? 1 : 0;
m_lineattr = ca >> 2;
}
}
}
@ -317,6 +369,11 @@ void i8275_device::device_timer(emu_timer &timer, device_timer_id id, int param,
}
}
if (end_of_row || m_end_of_screen)
{
vsp = 1;
}
if (!m_display_cb.isnull())
m_display_cb(m_bitmap,
sx * m_hpixels_per_column, // x position on screen of starting point
@ -489,18 +546,33 @@ WRITE8_MEMBER( i8275_device::dack_w )
m_fifo_next = true;
}
if (m_buffer_idx == CHARACTERS_PER_ROW)
switch (data)
{
case SCC_END_OF_ROW_DMA:
// stop DMA
// TODO should read one more character if DMA burst not completed
break;
case SCC_END_OF_SCREEN_DMA:
m_dma_stop = true;
// TODO should read one more character if DMA burst not completed
break;
default:
if (m_buffer_idx == CHARACTERS_PER_ROW)
{
// stop DMA
}
else if (!(m_buffer_idx % DMA_BURST_COUNT))
{
m_drq_on_timer->adjust(clocks_to_attotime(DMA_BURST_SPACE));
}
else
{
m_drq_on_timer->adjust(attotime::zero);
}
}
else if (!(m_buffer_idx % DMA_BURST_COUNT))
{
m_drq_on_timer->adjust(clocks_to_attotime(DMA_BURST_SPACE));
}
else
{
m_drq_on_timer->adjust(attotime::zero);
}
}
}

32
src/emu/video/i8275.h
View File

@ -154,20 +154,34 @@ protected:
enum
{
CA_H = 0x01,
CA_B = 0x02,
CA_CCCC = 0x3c
CA_H = 0x01,
CA_B = 0x02,
CA_CCCC = 0x3c,
CA_LTEN = 0x01,
CA_VSP = 0x02,
CA_LA0 = 0x04,
CA_LA1 = 0x08
};
enum
{
FAC_H = 0x01,
FAC_B = 0x02,
FAC_GG = 0x0c,
FAC_R = 0x10,
FAC_U = 0x20
SCC_END_OF_ROW = 0xf0,
SCC_END_OF_ROW_DMA = 0xf1,
SCC_END_OF_SCREEN = 0xf2,
SCC_END_OF_SCREEN_DMA = 0xf3
};
enum
{
FAC_H = 0x01,
FAC_B = 0x02,
FAC_GG = 0x0c,
FAC_R = 0x10,
FAC_U = 0x20
};
static const int character_attribute[3][16];
devcb2_write_line m_write_irq;
devcb2_write_line m_write_drq;
devcb2_write_line m_write_hrtc;
@ -203,6 +217,8 @@ protected:
int m_vrtc_scanline;
int m_vrtc_drq_scanline;
bool m_du;
bool m_dma_stop;
bool m_end_of_screen;
int m_cursor_blink;
int m_char_blink;