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-rw-r--r--src/devices/bus/wangpc/mvc.cpp333
1 files changed, 333 insertions, 0 deletions
diff --git a/src/devices/bus/wangpc/mvc.cpp b/src/devices/bus/wangpc/mvc.cpp
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index 00000000000..9a2e74a0f4a
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+++ b/src/devices/bus/wangpc/mvc.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Curt Coder
+/**********************************************************************
+
+ Wang PC PM-001B Medium-Resolution Video Controller emulation
+
+**********************************************************************/
+
+/*
+
+ TODO:
+
+ - character clock
+ - blink
+
+*/
+
+#include "mvc.h"
+
+
+
+//**************************************************************************
+// MACROS/CONSTANTS
+//**************************************************************************
+
+#define LOG 0
+
+#define OPTION_ID 0x15
+
+#define MC6845_TAG "mc6845"
+#define SCREEN_TAG "screen"
+
+#define VIDEO_RAM_SIZE 0x800
+#define CHAR_RAM_SIZE 0x1000
+#define BITMAP_RAM_SIZE 0x4000
+
+#define OPTION_VRAM BIT(m_option, 0)
+#define OPTION_VSYNC BIT(m_option, 3)
+
+#define ATTR_BLINK BIT(attr, 0)
+#define ATTR_REVERSE BIT(attr, 1)
+#define ATTR_BLANK BIT(attr, 2)
+#define ATTR_BOLD BIT(attr, 3)
+#define ATTR_OVERSCORE BIT(attr, 4)
+#define ATTR_UNDERSCORE BIT(attr, 5)
+#define ATTR_SUBSCRIPT BIT(attr, 6)
+#define ATTR_SUPERSCRIPT BIT(attr, 7)
+
+static const rgb_t PALETTE_MVC[] =
+{
+ rgb_t::black,
+ rgb_t(0x00, 0x80, 0x00),
+ rgb_t(0x00, 0xff, 0x00)
+};
+
+
+
+//**************************************************************************
+// DEVICE DEFINITIONS
+//**************************************************************************
+
+const device_type WANGPC_MVC = &device_creator<wangpc_mvc_device>;
+
+
+//-------------------------------------------------
+// mc6845
+//-------------------------------------------------
+
+MC6845_UPDATE_ROW( wangpc_mvc_device::crtc_update_row )
+{
+ for (int sx = 0; sx < 50; sx++)
+ {
+ offs_t addr = (y * 50) + sx;
+ UINT16 data = m_bitmap_ram[addr];
+
+ for (int bit = 0; bit < 16; bit++)
+ {
+ int x = (sx * 16) + bit;
+ int color = BIT(data, 15) && de;
+
+ bitmap.pix32(vbp + y, hbp + x) = PALETTE_MVC[color];
+
+ data <<= 1;
+ }
+ }
+
+ for (int column = 0; column < x_count; column++)
+ {
+ UINT16 code = m_video_ram[((ma + column) & 0x7ff)];
+ UINT8 attr = code & 0xff;
+
+ UINT8 new_ra = ra + 1;
+
+ if (ATTR_SUPERSCRIPT)
+ {
+ new_ra = ra + 3;
+ }
+ else if (ATTR_SUBSCRIPT)
+ {
+ new_ra = ra;
+ }
+
+ offs_t addr = ((code >> 8) << 4) | (new_ra & 0x0f);
+ UINT16 data = m_char_ram[addr & 0xfff];
+
+ if ((column == cursor_x) || (!ra && ATTR_OVERSCORE) || ((ra == 9) && ATTR_UNDERSCORE))
+ {
+ data = 0xffff;
+ }
+
+ for (int bit = 0; bit < 10; bit++)
+ {
+ int x = (column * 10) + bit;
+ int color = ((BIT(data, 9) & !ATTR_BLANK) ^ ATTR_REVERSE);
+
+ if ((color | bitmap.pix32(vbp + y, hbp + x)) & ATTR_BOLD) color = 2;
+ if (color) bitmap.pix32(vbp + y, hbp + x) = de ? PALETTE_MVC[color] : rgb_t::black;
+
+ data <<= 1;
+ }
+ }
+}
+
+WRITE_LINE_MEMBER( wangpc_mvc_device::vsync_w )
+{
+ if (OPTION_VSYNC && state)
+ {
+ set_irq(ASSERT_LINE);
+ }
+}
+
+//-------------------------------------------------
+// MACHINE_CONFIG_FRAGMENT( wangpc_mvc )
+//-------------------------------------------------
+
+static MACHINE_CONFIG_FRAGMENT( wangpc_mvc )
+ MCFG_SCREEN_ADD(SCREEN_TAG, RASTER)
+ MCFG_SCREEN_UPDATE_DEVICE(MC6845_TAG, mc6845_device, screen_update)
+ MCFG_SCREEN_SIZE(80*10, 25*12)
+ MCFG_SCREEN_VISIBLE_AREA(0, 80*10-1, 0, 25*12-1)
+ MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500))
+ MCFG_SCREEN_REFRESH_RATE(60)
+
+ MCFG_MC6845_ADD(MC6845_TAG, MC6845_1, SCREEN_TAG, XTAL_14_31818MHz/16)
+ MCFG_MC6845_SHOW_BORDER_AREA(true)
+ MCFG_MC6845_CHAR_WIDTH(10)
+ MCFG_MC6845_UPDATE_ROW_CB(wangpc_mvc_device, crtc_update_row)
+ MCFG_MC6845_OUT_VSYNC_CB(WRITELINE(wangpc_mvc_device, vsync_w))
+MACHINE_CONFIG_END
+
+
+//-------------------------------------------------
+// machine_config_additions - device-specific
+// machine configurations
+//-------------------------------------------------
+
+machine_config_constructor wangpc_mvc_device::device_mconfig_additions() const
+{
+ return MACHINE_CONFIG_NAME( wangpc_mvc );
+}
+
+
+
+//**************************************************************************
+// INLINE HELPERS
+//**************************************************************************
+
+//-------------------------------------------------
+// set_irq -
+//-------------------------------------------------
+
+inline void wangpc_mvc_device::set_irq(int state)
+{
+ m_irq = state;
+
+ m_bus->irq3_w(m_irq);
+}
+
+
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// wangpc_mvc_device - constructor
+//-------------------------------------------------
+
+wangpc_mvc_device::wangpc_mvc_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+ device_t(mconfig, WANGPC_MVC, "Wang PC Medium Resolution Video Card", tag, owner, clock, "wangpc_mvc", __FILE__),
+ device_wangpcbus_card_interface(mconfig, *this),
+ m_crtc(*this, MC6845_TAG),
+ m_video_ram(*this, "video_ram"),
+ m_char_ram(*this, "char_ram"),
+ m_bitmap_ram(*this, "bitmap_ram"),
+ m_option(0),
+ m_irq(CLEAR_LINE)
+{
+}
+
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void wangpc_mvc_device::device_start()
+{
+ // allocate memory
+ m_video_ram.allocate(VIDEO_RAM_SIZE);
+ m_char_ram.allocate(CHAR_RAM_SIZE);
+ m_bitmap_ram.allocate(BITMAP_RAM_SIZE);
+
+ // state saving
+ save_item(NAME(m_option));
+ save_item(NAME(m_irq));
+}
+
+
+//-------------------------------------------------
+// device_reset - device-specific reset
+//-------------------------------------------------
+
+void wangpc_mvc_device::device_reset()
+{
+ m_option = 0;
+
+ set_irq(CLEAR_LINE);
+}
+
+
+//-------------------------------------------------
+// wangpcbus_mrdc_r - memory read
+//-------------------------------------------------
+
+UINT16 wangpc_mvc_device::wangpcbus_mrdc_r(address_space &space, offs_t offset, UINT16 mem_mask)
+{
+ UINT16 data = 0xffff;
+
+ if (OPTION_VRAM)
+ {
+ if (offset >= 0xe0000/2 && offset < 0xe8000/2)
+ {
+ data = m_bitmap_ram[offset & 0x3fff];
+ }
+ else if (offset >= 0xf0000/2 && offset < 0xf1000/2)
+ {
+ data = m_video_ram[offset & 0x7ff];
+ }
+ else if (offset >= 0xf2000/2 && offset < 0xf4000/2)
+ {
+ data = m_char_ram[offset & 0xfff];
+ }
+ }
+
+ return data;
+}
+
+
+//-------------------------------------------------
+// wangpcbus_amwc_w - memory write
+//-------------------------------------------------
+
+void wangpc_mvc_device::wangpcbus_amwc_w(address_space &space, offs_t offset, UINT16 mem_mask, UINT16 data)
+{
+ if (OPTION_VRAM)
+ {
+ if (offset >= 0xe0000/2 && offset < 0xe8000/2)
+ {
+ m_bitmap_ram[offset & 0x3fff] = data;
+ }
+ else if (offset >= 0xf0000/2 && offset < 0xf1000/2)
+ {
+ m_video_ram[offset & 0x7ff] = data;
+ }
+ else if (offset >= 0xf2000/2 && offset < 0xf4000/2)
+ {
+ m_char_ram[offset & 0xfff] = data;
+ }
+ }
+}
+
+
+//-------------------------------------------------
+// wangpcbus_iorc_r - I/O read
+//-------------------------------------------------
+
+UINT16 wangpc_mvc_device::wangpcbus_iorc_r(address_space &space, offs_t offset, UINT16 mem_mask)
+{
+ UINT16 data = 0xffff;
+
+ if (sad(offset))
+ {
+ switch (offset & 0x7f)
+ {
+ case 0xfe/2:
+ data = 0xff00 | (m_irq << 7) | OPTION_ID;
+
+ set_irq(CLEAR_LINE);
+ break;
+ }
+ }
+
+ return data;
+}
+
+
+//-------------------------------------------------
+// wangpcbus_aiowc_w - I/O write
+//-------------------------------------------------
+
+void wangpc_mvc_device::wangpcbus_aiowc_w(address_space &space, offs_t offset, UINT16 mem_mask, UINT16 data)
+{
+ if (sad(offset) && ACCESSING_BITS_0_7)
+ {
+ switch (offset & 0x7f)
+ {
+ case 0x00/2:
+ m_crtc->address_w(space, 0, data & 0xff);
+ break;
+
+ case 0x02/2:
+ m_crtc->register_w(space, 0, data & 0xff);
+ break;
+
+ case 0x10/2:
+ case 0x12/2:
+ if (LOG) logerror("MVC option %02x\n", data & 0xff);
+
+ m_option = data & 0xff;
+ break;
+ }
+ }
+}