// license:BSD-3-Clause
// copyright-holders:Sven Schnelle
#include "emu.h"
#include "nereid.h"
#define VERBOSE 0
#include "logmacro.h"
DEFINE_DEVICE_TYPE(NEREID, nereid_device, "nereid", "HP Nereid ASIC")
nereid_device::nereid_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock) :
device_t(mconfig, type, tag, owner, clock),
device_palette_interface(mconfig, *this),
m_red(0),
m_green(0),
m_blue(0),
m_index(0),
m_plane_mask(0)
{
}
nereid_device::nereid_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
nereid_device(mconfig, NEREID, tag, owner, clock)
{
}
void nereid_device::device_start()
{
save_item(NAME(m_red));
save_item(NAME(m_green));
save_item(NAME(m_blue));
save_item(NAME(m_index));
save_item(NAME(m_plane_mask));
save_item(NAME(m_overlay_ctl));
save_item(NAME(m_overlay_index));
save_item(NAME(m_unknown_a0));
}
void nereid_device::device_reset()
{
for (int i = 0; i < palette_entries(); i++)
set_pen_color(i, rgb_t(0, 0, 0));
m_index = 0;
m_plane_mask = 0;
m_overlay_ctl = 0;
m_red = 0;
m_green = 0;
m_blue = 0;
m_unknown_a0 = 0;
m_overlay_index = 0;
}
READ16_MEMBER(nereid_device::ctrl_r)
{
LOG("NEREID ctrl_r: %02X\n", offset);
switch (offset & 0x7f) {
case NEREID_BUSY:
return 0;
case NEREID_RED_DATA:
return 0xff00 | m_red;
case NEREID_GREEN_DATA:
return 0xff00 | m_green;
case NEREID_BLUE_DATA:
return 0xff00 | m_blue;
case NEREID_INDEX:
return 0xff00 | ~m_index;
case NEREID_INDEX0:
return 0xff00 | m_index;
case NEREID_OVERLAY_CTL:
return 0xff00 | m_overlay_ctl;
case NEREID_WRITE_STROBE:
return 0xff00;
case NEREID_PLANE_MASK:
return 0xff00 | m_plane_mask;
case NEREID_UNKNOWN_A0:
return 0xff00 | m_unknown_a0;
case NEREID_OVERLAY_INDEX:
return 0xff00 | m_overlay_index;
case NEREID_REV:
return 0xff01;
default:
LOG("NEREID ctrl_r: unknown register %04X\n", offset);
return 0xffff;//space.unmap();
}
return 0xffff;
}
WRITE16_MEMBER(nereid_device::ctrl_w)
{
LOG("NEREID: ctrl_w %02X = %02X\n", offset << 1, data);
data &= 0xff;
switch (offset & 0x7f) {
case NEREID_RED_DATA:
m_red = data;
LOG("W NEREID_RED_DATA = %04X\n", m_red);
break;
case NEREID_GREEN_DATA:
m_green = data;
LOG("W NEREID_GREEN_DATA = %04X\n", m_green);
break;
case NEREID_BLUE_DATA:
m_blue = data;
LOG("W NEREID_BLUE_DATA = %04X\n", m_blue);
break;
case NEREID_INDEX:
m_index = ~data;
LOG("W NEREID_INDEX = %04X\n", m_index);
break;
case NEREID_INDEX0:
m_index =data;
LOG("W NEREID_INDEX0 = %04X\n", data);
break;
case NEREID_WRITE_STROBE:
if (m_overlay_index & 8) {
const int index = (m_overlay_index >> 1) & 0x3;
LOG("NEREID: set overlay color index %u: rgb_t(%u,%u,%u)\n",
index, m_red, m_green, m_blue);
set_pen_color(index | 0x100, rgb_t(m_red, m_green, m_blue));
} else {
LOG("NEREID: set video color index %u: rgb_t(%u,%u,%u)\n",
m_index, m_red, m_green, m_blue);
set_pen_color(m_index, rgb_t(m_red, m_green, m_blue));
}
break;
case NEREID_READ_STROBE:
{
rgb_t tmp = pen_color(m_index);
m_red = tmp.r();
m_green = tmp.g();
m_blue = tmp.b();
break;
}
case NEREID_PLANE_MASK:
m_plane_mask = data;
LOG("W NEREID_PLANE_MASK = %02x\n", m_plane_mask);
break;
case NEREID_OVERLAY_CTL:
m_overlay_ctl = data;
LOG("W NEREID_OVERLAY_CTL = %02x\n", m_overlay_ctl);
break;
case NEREID_UNKNOWN_A0:
m_unknown_a0 = data;
LOG("UW A0 = %04x\n", data);
break;
case NEREID_OVERLAY_INDEX:
m_overlay_index = data;
LOG("W OVERLAY_INDEX = %04x\n", data);
break;
default:
LOG("nereid::ctrl_w: unknown %X = %04X (mask %04X)\n", offset << 1, data, mem_mask);
break;
}
}
rgb_t nereid_device::map_color(uint8_t input, uint8_t ovl)
{
ovl &= m_overlay_ctl;
if (ovl == 0) {
return pen_color(input & m_plane_mask);
} else {
return pen_color((ovl & m_plane_mask) | 0x100);
}
}