// license:BSD-3-Clause
// copyright-holders:Curt Coder
/**********************************************************************
VideoBrain UV201/UV202 video chip emulation
**********************************************************************/
#include "emu.h"
#include "uv201.h"
//**************************************************************************
// MACROS / CONSTANTS
//**************************************************************************
#define LOG 1
// screen parameters
#define SCREEN_WIDTH 232
#define SCREEN_HEIGHT 262
#define VISAREA_WIDTH 193
#define VBLANK_WIDTH 21
#define HBLANK_WIDTH 39
#define HSYNC_WIDTH 18
#define HFP_WIDTH 16
#define HBP_WIDTH 5
#define HBLANK_END HSYNC_WIDTH + HFP_WIDTH
#define HBLANK_START HBLANK_END + VISAREA_WIDTH
// write-only registers
#define REGISTER_COMMAND 0xf7
#define REGISTER_BACKGROUND 0xf5
#define REGISTER_FINAL_MODIFIER 0xf2
#define REGISTER_Y_INTERRUPT 0xf0
// read-only registers
#define REGISTER_X_FREEZE 0xf8
#define REGISTER_Y_FREEZE_LOW 0xf9
#define REGISTER_Y_FREEZE_HIGH 0xfa
#define REGISTER_CURRENT_Y_LOW 0xfb
// read/write registers - RAM memory
#define RAM_RP_LO 0x00 // cartridge pointer low order
#define RAM_RP_HI_COLOR 0x10 // cartridge pointer high order and color
#define RAM_DX_INT_XCOPY 0x20 // dX, intensity, X-copy
#define RAM_DY 0x30 // dY
#define RAM_X 0x40 // X value
#define RAM_Y_LO_A 0x50 // Y value low order list A
#define RAM_Y_LO_B 0x60 // Y value low order list B
#define RAM_XY_HI_A 0x70 // Y value high order and X order list A
#define RAM_XY_HI_B 0x80 // Y value high order and X order list B
// command register bits
#define COMMAND_YINT_H_O 0x80
#define COMMAND_A_B 0x40
#define COMMAND_Y_ZM 0x20
#define COMMAND_KBD 0x10
#define COMMAND_INT 0x08
#define COMMAND_ENB 0x04
#define COMMAND_FRZ 0x02
#define COMMAND_X_ZM 0x01
#define IS_CHANGED(_bit) \
((m_cmd & _bit) != (data & _bit))
#define RAM(_offset) \
m_ram[_offset + i]
#define RAM_XORD(_offset) \
m_ram[_offset + xord]
#define IS_VISIBLE(_y) \
((_y >= cliprect.min_y) && (_y <= cliprect.max_y))
#define DRAW_PIXEL(_scanline, _dot) \
if (IS_VISIBLE(_scanline)) bitmap.pix32((_scanline), HSYNC_WIDTH + HFP_WIDTH + _dot) = m_palette_val[pixel];
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
// device type definition
DEFINE_DEVICE_TYPE(UV201, uv201_device, "uv201", "UV201")
//-------------------------------------------------
// uv201_device - constructor
//-------------------------------------------------
uv201_device::uv201_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
device_t(mconfig, UV201, tag, owner, clock),
device_video_interface(mconfig, *this),
m_write_ext_int(*this),
m_write_hblank(*this),
m_read_db(*this)
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void uv201_device::device_start()
{
// resolve callbacks
m_write_ext_int.resolve_safe();
m_write_hblank.resolve_safe();
m_read_db.resolve_safe(0);
// allocate timers
m_timer_y_odd = timer_alloc(TIMER_Y_ODD);
m_timer_y_even = timer_alloc(TIMER_Y_EVEN);
m_timer_hblank_on = timer_alloc(TIMER_HBLANK_ON);
m_timer_hblank_off = timer_alloc(TIMER_HBLANK_OFF);
initialize_palette();
memset(m_ram, 0x00, sizeof(m_ram));
m_y_int = 0;
m_fmod = 0;
m_bg = 0;
m_cmd = 0;
m_freeze_x = 0;
m_freeze_y = 0;
m_field = 0;
// state saving
save_item(NAME(m_ram));
save_item(NAME(m_y_int));
save_item(NAME(m_fmod));
save_item(NAME(m_bg));
save_item(NAME(m_cmd));
save_item(NAME(m_freeze_x));
save_item(NAME(m_freeze_y));
save_item(NAME(m_field));
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void uv201_device::device_reset()
{
m_write_ext_int(CLEAR_LINE);
m_write_hblank(1);
m_timer_hblank_off->adjust(attotime::from_ticks( HBLANK_END, m_clock ));
}
//-------------------------------------------------
// device_timer - handle timer events
//-------------------------------------------------
void uv201_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
{
int scanline = screen().vpos();
switch (id)
{
case TIMER_Y_ODD:
case TIMER_Y_EVEN:
if ((m_cmd & COMMAND_INT) && !(m_cmd & COMMAND_FRZ))
{
if (LOG) logerror("Y-Interrupt at scanline %u\n", scanline);
m_freeze_y = scanline;
m_write_ext_int(ASSERT_LINE);
m_write_ext_int(CLEAR_LINE);
}
break;
case TIMER_HBLANK_ON:
m_write_hblank(1);
m_timer_hblank_off->adjust(attotime::from_ticks( HBLANK_WIDTH, m_clock ) );
break;
case TIMER_HBLANK_OFF:
m_write_hblank(0);
m_timer_hblank_on->adjust(attotime::from_ticks( VISAREA_WIDTH, m_clock ) );
break;
}
}
//-------------------------------------------------
// initialize_palette -
//-------------------------------------------------
void uv201_device::initialize_palette()
{
uint8_t offlointensity = 0x00;
uint8_t offhiintensity = 0xc0;
uint8_t onlointensity = 0xa0;
uint8_t onhiintensity = 0xff;
for (int i = 0; i < 4; i++)
{
int offset = i * 8;
uint8_t onvalue, offvalue;
if (offset < 16)
{
offvalue = offlointensity;
onvalue = onlointensity;
}
else
{
offvalue = offhiintensity;
onvalue = onhiintensity;
}
m_palette_val[offset + 0] = rgb_t(offvalue, offvalue, offvalue); // black
m_palette_val[offset + 1] = rgb_t(onvalue, offvalue, offvalue); // red
m_palette_val[offset + 2] = rgb_t(offvalue, onvalue, offvalue); // green
m_palette_val[offset + 3] = rgb_t(onvalue, onvalue, offvalue); // red-green
m_palette_val[offset + 4] = rgb_t(offvalue, offvalue, onvalue); // blue
m_palette_val[offset + 5] = rgb_t(onvalue, offvalue, onvalue); // red-blue
m_palette_val[offset + 6] = rgb_t(offvalue, onvalue, onvalue); // green-blue
m_palette_val[offset + 7] = rgb_t(onvalue, onvalue, onvalue); // white
}
}
//-------------------------------------------------
// get_field_vpos - get scanline within field
//-------------------------------------------------
int uv201_device::get_field_vpos()
{
int vpos = screen().vpos();
if (vpos >= SCREEN_HEIGHT)
{
// even field
vpos -= SCREEN_HEIGHT;
}
return vpos;
}
//-------------------------------------------------
// get_field - get video field
//-------------------------------------------------
int uv201_device::get_field()
{
return screen().vpos() < SCREEN_HEIGHT;
}
//-------------------------------------------------
// set_y_interrupt - set Y interrupt timer
//-------------------------------------------------
void uv201_device::set_y_interrupt()
{
int scanline = ((m_cmd & COMMAND_YINT_H_O) << 1) | m_y_int;
m_timer_y_odd->adjust(screen().time_until_pos(scanline), 0, screen().frame_period());
//m_timer_y_even->adjust(screen().time_until_pos(scanline + SCREEN_HEIGHT), 0, screen().frame_period());
}
//-------------------------------------------------
// do_partial_update - update screen
//-------------------------------------------------
void uv201_device::do_partial_update()
{
int vpos = screen().vpos();
if (LOG) logerror("Partial screen update at scanline %u\n", vpos);
screen().update_partial(vpos);
}
//-------------------------------------------------
// read -
//-------------------------------------------------
READ8_MEMBER( uv201_device::read )
{
uint8_t data = 0xff;
switch (offset)
{
case REGISTER_X_FREEZE:
data = m_freeze_x;
if (LOG) logerror("X-Freeze %02x\n", data);
break;
case REGISTER_Y_FREEZE_LOW:
data = m_freeze_y & 0xff;
if (LOG) logerror("Y-Freeze Low %02x\n", data);
break;
case REGISTER_Y_FREEZE_HIGH:
/*
bit signal description
0 Y-F8 Y freeze high order (MSB) bit
1 Y-C8 current Y counter high order (MSB) bit
2
3
4
5
6
7 O/_E odd/even field
*/
data = (get_field() << 7) | (BIT(get_field_vpos(), 8) << 1) | BIT(m_freeze_y, 8);
if (LOG) logerror("Y-Freeze High %02x\n", data);
break;
case REGISTER_CURRENT_Y_LOW:
data = get_field_vpos() & 0xff;
if (LOG) logerror("Current-Y Low %02x\n", data);
break;
default:
if (offset < 0x90)
data = m_ram[offset];
else
if (LOG) logerror("Unknown VLSI read from %02x!\n", offset);
}
return data;
}
//-------------------------------------------------
// write -
//-------------------------------------------------
WRITE8_MEMBER( uv201_device::write )
{
switch (offset)
{
case REGISTER_Y_INTERRUPT:
if (LOG) logerror("Y-Interrupt %02x\n", data);
if (m_y_int != data)
{
m_y_int = data;
set_y_interrupt();
}
break;
case REGISTER_FINAL_MODIFIER:
/*
bit signal description
0 RED red
1 GREEN green
2 BLUE blue
3 INT 0 intensity 0
4 INT 1 intensity 1
5 not used
6 not used
7 not used
*/
if (LOG) logerror("Final Modifier %02x\n", data);
do_partial_update();
m_fmod = data & 0x1f;
break;
case REGISTER_BACKGROUND:
/*
bit signal description
0 RED red
1 GREEN green
2 BLUE blue
3 INT 0 intensity 0
4 INT 1 intensity 1
5 not used
6 not used
7 not used
*/
if (LOG) logerror("Background %02x\n", data);
do_partial_update();
m_bg = data & 0x1f;
break;
case REGISTER_COMMAND:
/*
bit signal description
0 X-ZM X zoom
1 FRZ freeze
2 ENB video enable
3 INT interrupt enable
4 KBD general purpose output
5 Y-ZM Y zoom
6 A/_B list selection
7 YINT H.O. Y COMMAND_INT register high order bit
*/
if (LOG) logerror("Command %02x\n", data);
if (IS_CHANGED(COMMAND_YINT_H_O))
{
set_y_interrupt();
}
if (IS_CHANGED(COMMAND_A_B) || IS_CHANGED(COMMAND_Y_ZM) || IS_CHANGED(COMMAND_X_ZM))
{
do_partial_update();
}
m_cmd = data;
break;
default:
if (offset < 0x90)
m_ram[offset] = data;
else
logerror("Unknown VLSI write %02x to %02x!\n", data, offset);
}
}
//-------------------------------------------------
// ext_int_w - external interrupt write
//-------------------------------------------------
WRITE_LINE_MEMBER( uv201_device::ext_int_w )
{
if (!state && (m_cmd & COMMAND_FRZ))
{
m_freeze_y = get_field_vpos();
m_freeze_x = screen().hpos();
}
}
//-------------------------------------------------
// kbd_r - keyboard select read
//-------------------------------------------------
READ_LINE_MEMBER( uv201_device::kbd_r )
{
return (m_cmd & COMMAND_KBD) ? 1 : 0;
}
//-------------------------------------------------
// screen_update -
//-------------------------------------------------
uint32_t uv201_device::screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect)
{
bitmap.fill(rgb_t(0x00,0x00,0x00), cliprect);
if (!(m_cmd & COMMAND_ENB))
{
return 0;
}
for (int y = 0; y < SCREEN_HEIGHT; y++)
{
for (int x = 0; x < VISAREA_WIDTH; x++)
{
int pixel = m_bg;
DRAW_PIXEL(y, x);
}
}
for (int i = 0; i < 16; i++)
{
uint8_t xy_hi = (m_cmd & COMMAND_A_B) ? RAM(RAM_XY_HI_A) : RAM(RAM_XY_HI_B);
uint8_t y_lo = (m_cmd & COMMAND_A_B) ? RAM(RAM_Y_LO_A) : RAM(RAM_Y_LO_B);
uint16_t y = (BIT(xy_hi, 7) << 8) | y_lo;
int xord = xy_hi & 0x0f;
uint8_t rp_hi_color = RAM_XORD(RAM_RP_HI_COLOR);
uint8_t rp_lo = RAM_XORD(RAM_RP_LO);
uint16_t rp = ((rp_hi_color << 8) | rp_lo) & 0x1fff;
if (rp < 0x800) rp |= 0x2000;
uint8_t dx_int_xcopy = RAM_XORD(RAM_DX_INT_XCOPY);
int color = ((dx_int_xcopy & 0x60) >> 2) | (BIT(rp_hi_color, 5) << 2) | (BIT(rp_hi_color, 6) << 1) | (BIT(rp_hi_color, 7));
uint8_t dx = dx_int_xcopy & 0x1f;
uint8_t dy = RAM_XORD(RAM_DY);
int xcopy = BIT(dx_int_xcopy, 7);
uint8_t x = RAM_XORD(RAM_X);
if (LOG) logerror("Object %u xord %u y %u x %u dy %u dx %u xcopy %u color %u rp %04x\n", i, xord, y, x, dy, dx, xcopy, color, rp);
if (rp == 0) continue;
if (y > SCREEN_HEIGHT) continue;
for (int sy = 0; sy < dy; sy++)
{
for (int sx = 0; sx < dx; sx++)
{
uint8_t data = m_read_db(rp);
for (int bit = 0; bit < 8; bit++)
{
int pixel = ((BIT(data, 7) ? color : m_bg) ^ m_fmod) & 0x1f;
if (m_cmd & COMMAND_Y_ZM)
{
int scanline = y + (sy * 2);
if (m_cmd & COMMAND_X_ZM)
{
int dot = (x * 2) + (sx * 16) + (bit * 2);
DRAW_PIXEL(scanline, dot);
DRAW_PIXEL(scanline, dot + 1);
DRAW_PIXEL(scanline + 1, dot);
DRAW_PIXEL(scanline + 1, dot + 1);
}
else
{
int dot = x + (sx * 8) + bit;
DRAW_PIXEL(scanline, dot);
DRAW_PIXEL(scanline + 1, dot);
}
}
else
{
int scanline = y + sy;
if (m_cmd & COMMAND_X_ZM)
{
int dot = (x * 2) + (sx * 16) + (bit * 2);
DRAW_PIXEL(scanline, dot);
DRAW_PIXEL(scanline, dot + 1);
}
else
{
int dot = x + (sx * 8) + bit;
DRAW_PIXEL(scanline, dot);
}
}
data <<= 1;
}
if (!xcopy) rp++;
}
if (xcopy) rp++;
}
}
return 0;
}