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// license: BSD-3-Clause
// copyright-holders: Dirk Best
/***************************************************************************
Brooktree Bt481/Bt482
256 Color, 15-bit, 16-bit, 24-bit RAMDAC
***************************************************************************/
#ifndef MAME_VIDEO_BT48X_H
#define MAME_VIDEO_BT48X_H
#pragma once
class bt481_device : public device_t, public device_palette_interface
{
public:
bt481_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
// color lookup
rgb_t pixel_select(uint8_t index) const { return pen_color(index & m_read_mask); } // P0-P7
rgb_t overlay_select(uint8_t index) const { return pen_color((256 + index) & m_overlay_mask); } // OL0-OL3
void map(address_map &map);
// accessable with RS0 and RS1
uint8_t address_r();
void address_w(uint8_t data);
uint8_t palette_r();
void palette_w(uint8_t data);
virtual uint8_t mask_r();
virtual void mask_w(uint8_t data);
void address_read_w(uint8_t data);
// accessable when RS2 is additionally connected
uint8_t overlay_address_r();
void overlay_address_w(uint8_t data);
void command_w(uint8_t data);
virtual uint8_t overlay_r();
virtual void overlay_w(uint8_t data);
void overlay_address_read_w(uint8_t data);
protected:
bt481_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock);
virtual void device_start() override ATTR_COLD;
// 256 color palette, 1 reserved entry, 15 overlay colors, 1 reserved entry, 3 cursor colors
virtual uint32_t palette_entries() const noexcept override { return 256 + 1 + 15 + 1 + 3; }
// indirect registers
static constexpr int READ_MASK_REGISTER = 0;
static constexpr int OVERLAY_MASK_REGISTER = 1;
static constexpr int COMMAND_REGISTER_B = 2;
static constexpr int CURSOR_REGISTER = 3;
// cursor modes
static constexpr int CURSOR_DISABLED = 0;
static constexpr int CURSOR_3_COLOR = 1;
static constexpr int CURSOR_COMPLEMENT = 2;
static constexpr int CURSOR_XWINDOWS = 3;
uint8_t m_cra;
uint8_t m_crb;
uint8_t m_color[3];
uint8_t m_addr;
uint8_t m_addr_rgb;
uint8_t m_indirect_index;
uint8_t m_read_mask;
uint8_t m_overlay_mask;
uint8_t m_cursor;
};
class bt482_device : public bt481_device
{
public:
bt482_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
virtual uint8_t mask_r() override;
virtual void mask_w(uint8_t data) override;
virtual uint8_t overlay_r() override;
virtual void overlay_w(uint8_t data) override;
// renders the hardware cursor
uint32_t screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
protected:
virtual void device_start() override ATTR_COLD;
// additional indirect registers
static constexpr int CURSOR_X_LOW_REGISTER = 4;
static constexpr int CURSOR_X_HIGH_REGISTER = 5;
static constexpr int CURSOR_Y_LOW_REGISTER = 6;
static constexpr int CURSOR_Y_HIGH_REGISTER = 7;
private:
uint8_t m_cram[256];
uint8_t m_cxlr;
uint8_t m_cxhr;
uint8_t m_cylr;
uint8_t m_cyhr;
uint16_t m_cx;
uint16_t m_cy;
};
// device type declaration
DECLARE_DEVICE_TYPE(BT481, bt481_device)
DECLARE_DEVICE_TYPE(BT482, bt482_device)
#endif // MAME_VIDEO_BT48X_H
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