// license:BSD-3-Clause // copyright-holders:Curt Coder #include "includes/pc1512.h" //************************************************************************** // CONSTANTS //************************************************************************** #define LOG 0 static const rgb_t PALETTE_1512[] = { rgb_t::black, rgb_t(0x00, 0x00, 0xaa), rgb_t(0x00, 0xaa, 0x00), rgb_t(0x00, 0xaa, 0xaa), rgb_t(0xaa, 0x00, 0x00), rgb_t(0xaa, 0x00, 0xaa), rgb_t(0xaa, 0x55, 0x00), rgb_t(0xaa, 0xaa, 0xaa), rgb_t(0x55, 0x55, 0x55), rgb_t(0x55, 0x55, 0xff), rgb_t(0x55, 0xff, 0x55), rgb_t(0x55, 0xff, 0xff), rgb_t(0xff, 0x55, 0x55), rgb_t(0xff, 0x55, 0xff), rgb_t(0xff, 0xff, 0x55), rgb_t::white }; static const int PALETTE_0[] = { 0, 3, 5, 7 }; static const int PALETTE_1[] = { 0, 2, 4, 6 }; static const int PALETTE_2[] = { 0, 3, 4, 7 }; enum { ALPHA_40 = 0, ALPHA_80, GRAPHICS_1, GRAPHICS_2 }; #define MODE_ALPHA_80 0x01 #define MODE_GRAPHICS 0x02 #define MODE_PALETTE_2 0x04 #define MODE_ENABLE_VIDEO 0x08 #define MODE_GRAPHICS_2 0x10 #define MODE_BLINK 0x20 #define COLOR_INTENSITY 0x10 #define COLOR_PALETTE_1 0x20 #define VFP_LORES 22 #define HFP_LORES 16 //************************************************************************** // VIDEO RAM ACCESS //************************************************************************** //------------------------------------------------- // video_ram_r - //------------------------------------------------- READ8_MEMBER( pc1512_state::video_ram_r ) { UINT8 data = 0; switch (get_display_mode(m_vdu_mode)) { case ALPHA_40: case ALPHA_80: data = m_video_ram[offset]; break; case GRAPHICS_1: data = m_video_ram[(offset << 2) | 3]; break; case GRAPHICS_2: data = m_video_ram[(offset << 2) | (m_vdu_rdsel ^ 0x03)]; break; } return data; } //------------------------------------------------- // video_ram_w - //------------------------------------------------- WRITE8_MEMBER( pc1512_state::video_ram_w ) { switch (get_display_mode(m_vdu_mode)) { case ALPHA_40: case ALPHA_80: m_video_ram[offset] = data; break; case GRAPHICS_1: m_video_ram[(offset << 2) | 3] = data; m_video_ram[(offset << 2) | 2] = data; m_video_ram[(offset << 2) | 1] = data; m_video_ram[(offset << 2) | 0] = data; break; case GRAPHICS_2: if (BIT(m_vdu_plane, 0)) m_video_ram[(offset << 2) | 3] = data; if (BIT(m_vdu_plane, 1)) m_video_ram[(offset << 2) | 2] = data; if (BIT(m_vdu_plane, 2)) m_video_ram[(offset << 2) | 1] = data; if (BIT(m_vdu_plane, 3)) m_video_ram[(offset << 2) | 0] = data; break; } } //------------------------------------------------- // vdu_r - //------------------------------------------------- READ8_MEMBER( pc1512_state::vdu_r ) { UINT8 data = 0; switch (offset) { case 1: case 3: case 5: case 7: data = m_vdu->register_r(space, 0); break; case 0xa: // VDU Status /* bit description 0 Toggle Bit 1 Light-pen latch select 2 Light-pen switch off 3 Frame Flyback Time 4 5 6 7 */ // toggle bit data |= m_toggle; m_toggle = !m_toggle; // light pen latch data |= m_lpen << 1; // light pen switch data |= 0x04; // vertical sync //data |= m_vdu->vsync_r(); int flyback = 0; if (machine().first_screen()->vpos() < VFP_LORES - 16) flyback = 1; if (machine().first_screen()->vpos() > VFP_LORES + 200) flyback = 1; data |= flyback << 3; break; } return data; } //------------------------------------------------- // vdu_w - //------------------------------------------------- WRITE8_MEMBER( pc1512_state::vdu_w ) { switch (offset) { case 0: case 2: case 4: case 6: m_vdu->address_w(space, 0, data); break; case 1: case 3: case 5: case 7: m_vdu->register_w(space, 0, data); break; case 8: // VDU Mode Control /* bit description 0 Select Alpha 80 Char mode (de-select 40 Char mode) 1 Select Graphics modes (de-select Alpha modes) 2 Select Palette 2 (de-select palettes 0,1) 3 Enable Video Display 4 Select Graphics Mode 2 (de-select graphics mode 1) 5 Enable Blinking Chars (disable intensified backgrounds) 6 7 */ if (LOG) logerror("VDU Mode Control %02x\n", data); if ((get_display_mode(m_vdu_mode) != GRAPHICS_2) && (get_display_mode(data) == GRAPHICS_2)) { m_vdu_plane = 0x0f; m_vdu_border = 0; } if (get_display_mode(data) != GRAPHICS_2) { m_vdu_rdsel = 0; } if (get_display_mode(m_vdu_mode) != get_display_mode(data)) { switch (get_display_mode(data)) { case ALPHA_40: case GRAPHICS_1: m_vdu->set_hpixels_per_column(8); m_vdu->set_clock(XTAL_28_63636MHz/32); break; case ALPHA_80: m_vdu->set_hpixels_per_column(8); m_vdu->set_clock(XTAL_28_63636MHz/16); break; case GRAPHICS_2: m_vdu->set_hpixels_per_column(16); m_vdu->set_clock(XTAL_28_63636MHz/32); break; } } m_vdu_mode = data; break; case 9: // VDU Colour Select /* bit description 0 1 2 3 4 5 6 7 */ if (LOG) logerror("VDU Colour Select %02x\n", data); m_vdu_color = data; break; case 0xb: // Clear Light Pen Latch if (LOG) logerror("VDU Clear Light Pen Latch\n"); m_lpen = 0; break; case 0xc: // Set Light Pen Latch if (LOG) logerror("VDU Set Light Pen Latch\n"); if (!m_lpen) { m_vdu->assert_light_pen_input(); } m_lpen = 1; break; case 0xd: // VDU Colour Plane Write /* bit description 0 Allow CPU write to Blue Plane 1 Allow CPU write to Green Plane 2 Allow CPU write to Red Plane 3 Allow CPU write to Intensity Plane 4 5 6 7 */ if (LOG) logerror("VDU Colour Plane Write %01x\n", data & 0x0f); if (get_display_mode(m_vdu_mode) == GRAPHICS_2) { m_vdu_plane = data; } break; case 0xe: // VDU Colour Plane Read /* bit description 0 Read Select bit 0 (RDSEL0) 1 Read Select bit 1 (RDSEL1) 2 3 4 5 6 7 */ if (LOG) logerror("VDU Colour Plane Read %u\n", data & 0x03); if (get_display_mode(m_vdu_mode) == GRAPHICS_2) { m_vdu_rdsel = data & 0x03; } break; case 0xf: // VDU Graphics Mode 2 Border /* bit description 0 Border Blue 1 Border Green 2 Border Red 3 Border Intensity 4 5 6 7 */ if (LOG) logerror("VDU Graphics Mode 2 Border %u\n", data & 0x0f); m_vdu_border = data; break; } } //------------------------------------------------- // mc6845 //------------------------------------------------- int pc1512_state::get_display_mode(UINT8 mode) { if (mode & MODE_GRAPHICS) { if (mode & MODE_GRAPHICS_2) { return GRAPHICS_2; } else { return GRAPHICS_1; } } else { if (mode & MODE_ALPHA_80) { return ALPHA_80; } else { return ALPHA_40; } } } offs_t pc1512_state::get_char_rom_offset() { return ((m_lk->read() >> 5) & 0x03) << 11; } MC6845_UPDATE_ROW( pc1512_state::draw_alpha ) { offs_t char_rom_offset = get_char_rom_offset(); UINT32 *p = &bitmap.pix32(y + vbp, hbp); if (get_display_mode(m_vdu_mode) == ALPHA_40) p = &bitmap.pix32(y + vbp, hbp); if (y > 199) return; for (int column = 0; column < x_count; column++) { UINT8 code = m_video_ram[(ma + column) << 1]; UINT8 attr = m_video_ram[((ma + column) << 1) + 1]; int fg = attr & 0x0f; int bg = attr >> 4; if (m_vdu_mode & MODE_BLINK) { bg &= 0x07; if (BIT(attr, 7) && !m_blink) { fg = bg; } } offs_t addr = char_rom_offset | (code << 3) | (ra & 0x07); UINT8 data = m_char_rom->base()[addr & 0x1fff]; if ((column == cursor_x) && m_cursor) { data = 0xff; } for (int bit = 0; bit < 8; bit++) { int color = BIT(data, 7) ? fg : bg; *p = PALETTE_1512[de ? color : 0]; p++; data <<= 1; } } } int pc1512_state::get_color(UINT8 data) { if (data == 0) return m_vdu_color & 0x0f; int color = PALETTE_0[data & 0x03]; if (m_vdu_color & COLOR_PALETTE_1) { color = PALETTE_1[data & 0x03]; } else if (m_vdu_mode & MODE_PALETTE_2) { color = PALETTE_2[data & 0x03]; } if (m_vdu_color & COLOR_INTENSITY) { color += 8; } return color; }; MC6845_UPDATE_ROW( pc1512_state::draw_graphics_1 ) { if (y > 199) return; UINT32 *p = &bitmap.pix32(y + vbp, hbp); for (int column = 0; column < x_count; column++) { offs_t offset = ((ra & 0x01) << 15) | ((ma + column) << 3); UINT16 b = (m_video_ram[offset | 3] << 8) | m_video_ram[offset | 7]; for (int x = 0; x < 8; x++) { *p = PALETTE_1512[de ? get_color((BIT(b, 15) << 1) | BIT(b, 14)) : 0]; p++; b <<= 2; } } } MC6845_UPDATE_ROW( pc1512_state::draw_graphics_2 ) { if (y > 199) return; UINT32 *p = &bitmap.pix32(y + vbp, hbp); for (int column = 0; column < x_count; column++) { offs_t offset = ((ra & 0x01) << 15) | ((ma + column) << 3); UINT16 i = BIT(m_vdu_color, 3) ? ((m_video_ram[offset | 0] << 8) | m_video_ram[offset | 4]) : 0; UINT16 r = BIT(m_vdu_color, 2) ? ((m_video_ram[offset | 1] << 8) | m_video_ram[offset | 5]) : 0; UINT16 g = BIT(m_vdu_color, 1) ? ((m_video_ram[offset | 2] << 8) | m_video_ram[offset | 6]) : 0; UINT16 b = BIT(m_vdu_color, 0) ? ((m_video_ram[offset | 3] << 8) | m_video_ram[offset | 7]) : 0; for (int x = 0; x < 16; x++) { *p = PALETTE_1512[de ? (BIT(i, 15) << 3) | (BIT(r, 15) << 2) | (BIT(g, 15) << 1) | BIT(b, 15) : 0]; p++; i <<= 1; r <<= 1; g <<= 1; b <<= 1; } } } MC6845_UPDATE_ROW( pc1512_state::crtc_update_row ) { switch (get_display_mode(m_vdu_mode)) { case ALPHA_40: case ALPHA_80: draw_alpha(bitmap, cliprect, ma, ra, y, x_count, cursor_x, de, hbp, vbp); break; case GRAPHICS_1: draw_graphics_1(bitmap, cliprect, ma, ra, y, x_count, cursor_x, de, hbp, vbp); break; case GRAPHICS_2: draw_graphics_2(bitmap, cliprect, ma, ra, y, x_count, cursor_x, de, hbp, vbp); break; } } void pc1512_state::video_start() { // allocate memory m_video_ram.allocate(0x10000); } UINT32 pc1512_state::screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect) { if (m_vdu_mode & MODE_ENABLE_VIDEO) { m_blink_ctr++; if (m_blink_ctr == 0x08) { m_cursor = !m_cursor; } else if (m_blink_ctr == 0x10) { m_cursor = !m_cursor; m_blink = !m_blink; m_blink_ctr = 0; } switch (get_display_mode(m_vdu_mode)) { case ALPHA_40: case GRAPHICS_1: screen.set_visible_area(0, 359, 0, 245); break; case ALPHA_80: case GRAPHICS_2: screen.set_visible_area(0, 831, 0, 245); break; } switch (get_display_mode(m_vdu_mode)) { case ALPHA_40: case ALPHA_80: case GRAPHICS_1: bitmap.fill(PALETTE_1512[m_vdu_color & 0x0f], cliprect); break; case GRAPHICS_2: bitmap.fill(PALETTE_1512[m_vdu_border & 0x0f], cliprect); break; } m_vdu->screen_update(screen, bitmap, cliprect); } else { bitmap.fill(rgb_t::black, cliprect); } return 0; } //------------------------------------------------- // MACHINE_CONFIG( pc1512 ) //------------------------------------------------- MACHINE_CONFIG_FRAGMENT( pc1512_video ) MCFG_SCREEN_ADD(SCREEN_TAG, RASTER) MCFG_SCREEN_UPDATE_DRIVER(pc1512_state, screen_update) MCFG_SCREEN_SIZE(80*8, 24*8) MCFG_SCREEN_VISIBLE_AREA(0, 80*8-1, 0, 24*8-1) MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500)) MCFG_SCREEN_REFRESH_RATE(50) MCFG_MC6845_ADD(AMS40041_TAG, AMS40041, SCREEN_TAG, XTAL_28_63636MHz/32) MCFG_MC6845_SHOW_BORDER_AREA(true) MCFG_MC6845_CHAR_WIDTH(8) MCFG_MC6845_UPDATE_ROW_CB(pc1512_state, crtc_update_row) MACHINE_CONFIG_END