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Diffstat (limited to 'src/devices/bus/c64/z80videopak.cpp')
-rw-r--r--src/devices/bus/c64/z80videopak.cpp213
1 files changed, 213 insertions, 0 deletions
diff --git a/src/devices/bus/c64/z80videopak.cpp b/src/devices/bus/c64/z80videopak.cpp
new file mode 100644
index 00000000000..fc6c3544b2c
--- /dev/null
+++ b/src/devices/bus/c64/z80videopak.cpp
@@ -0,0 +1,213 @@
+// license:BSD-3-Clause
+// copyright-holders:Curt Coder, smf
+/*
+
+Z80 Video Pak
+(c) 1983 Data 20 Corporation
+
+*/
+
+#include "emu.h"
+#include "z80videopak.h"
+#include "screen.h"
+
+
+
+//**************************************************************************
+// MACROS/CONSTANTS
+//**************************************************************************
+
+#define RAM_SIZE 0x800
+
+#define HD46505SP_TAG "mc6845"
+#define MC6845_SCREEN_TAG "screen80"
+
+
+
+//**************************************************************************
+// DEVICE DEFINITIONS
+//**************************************************************************
+
+DEFINE_DEVICE_TYPE(C64_Z80VIDEOPAK, c64_z80videopak_device, "c64_z80videopak", "Data20 Z80 Video Pak")
+
+
+//-------------------------------------------------
+// ROM( c64_z80videopak )
+//-------------------------------------------------
+
+ROM_START( c64_z80videopak )
+ ROM_REGION( 0x800, HD46505SP_TAG, 0 )
+ ROM_LOAD( "c68297 vid pak cg.u18", 0x000, 0x800, CRC(9edf5e58) SHA1(4b244e6d94a7653a2e52c351589f0b469119fb04) )
+ROM_END
+
+
+//-------------------------------------------------
+// rom_region - device-specific ROM region
+//-------------------------------------------------
+
+const tiny_rom_entry *c64_z80videopak_device::device_rom_region() const
+{
+ return ROM_NAME( c64_z80videopak );
+}
+
+//-------------------------------------------------
+// mc6845
+//-------------------------------------------------
+
+MC6845_UPDATE_ROW( c64_z80videopak_device::crtc_update_row )
+{
+ pen_t const *const pen = m_palette->pens();
+
+ for (int column = 0; column < x_count; column++)
+ {
+ uint8_t const code = m_ram[((ma + column) & 0x7ff)];
+ uint16_t const addr = (m_case << 10) | ((code & 0x7f) << 3) | (ra & 0x07);
+ uint8_t data = m_char_rom->base()[addr & 0x7ff];
+
+ if (column == cursor_x)
+ {
+ data = 0xff;
+ }
+
+ for (int bit = 0; bit < 8; bit++)
+ {
+ int const x = (column * 8) + bit;
+ int const color = BIT(data ^ code, 7) && de;
+
+ bitmap.pix(vbp + y, hbp + x) = pen[color];
+
+ data <<= 1;
+ }
+ }
+}
+
+//-------------------------------------------------
+// GFXDECODE( c64_videopak )
+//-------------------------------------------------
+
+static GFXDECODE_START( gfx_c64_z80videopak )
+ GFXDECODE_ENTRY(HD46505SP_TAG, 0x0000, gfx_8x8x1, 0, 1)
+GFXDECODE_END
+
+
+//-------------------------------------------------
+// device_add_mconfig - add device configuration
+//-------------------------------------------------
+
+void c64_z80videopak_device::device_add_mconfig(machine_config &config)
+{
+ c64_cpm_cartridge_device::device_add_mconfig(config);
+
+ screen_device &screen(SCREEN(config, MC6845_SCREEN_TAG, SCREEN_TYPE_RASTER, rgb_t::white()));
+ screen.set_screen_update(HD46505SP_TAG, FUNC(hd6845s_device::screen_update));
+ screen.set_size(80*8, 24*8);
+ screen.set_visarea(0, 80*8-1, 0, 24*8-1);
+ screen.set_refresh_hz(50);
+
+ GFXDECODE(config, "gfxdecode", m_palette, gfx_c64_z80videopak);
+ PALETTE(config, m_palette, palette_device::MONOCHROME);
+
+ HD6845S(config, m_crtc, XTAL(14'318'181) / 8);
+ m_crtc->set_screen(MC6845_SCREEN_TAG);
+ m_crtc->set_show_border_area(true);
+ m_crtc->set_char_width(8);
+ m_crtc->set_update_row_callback(FUNC(c64_z80videopak_device::crtc_update_row));
+}
+
+
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// c64_z80videopak_device - constructor
+//-------------------------------------------------
+
+c64_z80videopak_device::c64_z80videopak_device(const machine_config& mconfig, const char* tag, device_t* owner, uint32_t clock) :
+ c64_cpm_cartridge_device(mconfig, C64_Z80VIDEOPAK, tag, owner, clock),
+ m_crtc(*this, HD46505SP_TAG),
+ m_palette(*this, "palette"),
+ m_char_rom(*this, HD46505SP_TAG),
+ m_ram(*this, "ram", RAM_SIZE, ENDIANNESS_LITTLE)
+{
+}
+
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void c64_z80videopak_device::device_start()
+{
+ // state saving
+ save_item(NAME(m_case));
+
+ c64_cpm_cartridge_device::device_start();
+}
+
+
+//-------------------------------------------------
+// device_reset - device-specific reset
+//-------------------------------------------------
+
+void c64_z80videopak_device::device_reset()
+{
+ m_case = 0;
+ m_exrom = 0;
+
+ c64_cpm_cartridge_device::device_reset();
+}
+
+
+//-------------------------------------------------
+// c64_cd_r - cartridge data read
+//-------------------------------------------------
+
+uint8_t c64_z80videopak_device::c64_cd_r(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2)
+{
+ if (!roml)
+ {
+ if (BIT(offset, 11))
+ data = m_ram[offset & 0x7ff];
+ else
+ data = m_roml[offset & 0x7ff];
+ }
+ else if (!io2 && !BIT(offset, 1))
+ {
+ if (BIT(offset, 0))
+ data = m_crtc->register_r();
+ }
+
+ return data;
+}
+
+
+//-------------------------------------------------
+// c64_cd_w - cartridge data write
+//-------------------------------------------------
+
+void c64_z80videopak_device::c64_cd_w(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2)
+{
+ c64_cpm_cartridge_device::c64_cd_w(offset, data, sphi2, ba, roml, romh, io1, io2);
+
+ if ((!m_exrom && offset >= 0x9800 && offset < 0xa000) ||
+ (m_exrom && offset >= 0xf800 && offset < 0x10000))
+ {
+ m_ram[offset & 0x7ff] = data;
+ }
+ else if (!io2 && !BIT(offset, 1))
+ {
+ if (!BIT(offset, 0))
+ m_crtc->address_w(data);
+ else
+ m_crtc->register_w(data);
+ }
+ else if (!io2)
+ {
+ m_case = BIT(data, 0);
+ // BIT(data, 1); // unknown
+ // BIT(data, 2); // unknown
+ m_exrom = BIT(data, 4);
+ }
+}