summaryrefslogtreecommitdiffstatshomepage
path: root/src/mame/drivers/b16.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/mame/drivers/b16.cpp')
-rw-r--r--src/mame/drivers/b16.cpp312
1 files changed, 312 insertions, 0 deletions
diff --git a/src/mame/drivers/b16.cpp b/src/mame/drivers/b16.cpp
new file mode 100644
index 00000000000..64904bff3c6
--- /dev/null
+++ b/src/mame/drivers/b16.cpp
@@ -0,0 +1,312 @@
+// license:BSD-3-Clause
+// copyright-holders:Angelo Salese
+/***************************************************************************
+
+ Hitachi B(asic Master?) 16
+
+ very preliminary driver by Angelo Salese
+
+ TODO:
+ - Driver is all made up of educated guesses (no documentation available)
+
+ 0xfcc67 after the ROM checksum to zero (bp 0xfc153 -> SI = 0) -> system boots
+
+****************************************************************************/
+
+#include "emu.h"
+#include "cpu/i86/i86.h"
+#include "video/mc6845.h"
+#include "machine/am9517a.h"
+
+
+
+class b16_state : public driver_device
+{
+public:
+ b16_state(const machine_config &mconfig, device_type type, const char *tag)
+ : driver_device(mconfig, type, tag),
+ m_vram(*this, "vram"),
+ m_dma8237(*this, "8237dma"),
+ m_maincpu(*this, "maincpu"),
+ m_gfxdecode(*this, "gfxdecode"),
+ m_palette(*this, "palette") { }
+
+ UINT8 *m_char_rom;
+ required_shared_ptr<UINT16> m_vram;
+ UINT8 m_crtc_vreg[0x100],m_crtc_index;
+
+ DECLARE_READ16_MEMBER(vblank_r);
+ DECLARE_WRITE8_MEMBER(b16_pcg_w);
+ DECLARE_WRITE8_MEMBER(b16_6845_address_w);
+ DECLARE_WRITE8_MEMBER(b16_6845_data_w);
+ DECLARE_READ8_MEMBER(unk_dev_r);
+ DECLARE_WRITE8_MEMBER(unk_dev_w);
+ DECLARE_READ8_MEMBER(memory_read_byte);
+ DECLARE_WRITE8_MEMBER(memory_write_byte);
+
+ virtual void video_start();
+ UINT32 screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
+
+ mc6845_device *m_mc6845;
+ required_device<am9517a_device> m_dma8237;
+ virtual void machine_start();
+ virtual void machine_reset();
+ required_device<cpu_device> m_maincpu;
+ required_device<gfxdecode_device> m_gfxdecode;
+ required_device<palette_device> m_palette;
+};
+
+#define mc6845_h_char_total (m_crtc_vreg[0])
+#define mc6845_h_display (m_crtc_vreg[1])
+#define mc6845_h_sync_pos (m_crtc_vreg[2])
+#define mc6845_sync_width (m_crtc_vreg[3])
+#define mc6845_v_char_total (m_crtc_vreg[4])
+#define mc6845_v_total_adj (m_crtc_vreg[5])
+#define mc6845_v_display (m_crtc_vreg[6])
+#define mc6845_v_sync_pos (m_crtc_vreg[7])
+#define mc6845_mode_ctrl (m_crtc_vreg[8])
+#define mc6845_tile_height (m_crtc_vreg[9]+1)
+#define mc6845_cursor_y_start (m_crtc_vreg[0x0a])
+#define mc6845_cursor_y_end (m_crtc_vreg[0x0b])
+#define mc6845_start_addr (((m_crtc_vreg[0x0c]<<8) & 0x3f00) | (m_crtc_vreg[0x0d] & 0xff))
+#define mc6845_cursor_addr (((m_crtc_vreg[0x0e]<<8) & 0x3f00) | (m_crtc_vreg[0x0f] & 0xff))
+#define mc6845_light_pen_addr (((m_crtc_vreg[0x10]<<8) & 0x3f00) | (m_crtc_vreg[0x11] & 0xff))
+#define mc6845_update_addr (((m_crtc_vreg[0x12]<<8) & 0x3f00) | (m_crtc_vreg[0x13] & 0xff))
+
+
+void b16_state::video_start()
+{
+ // find memory regions
+ m_char_rom = memregion("pcg")->base();
+}
+
+
+UINT32 b16_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
+{
+ int x,y;
+ int xi,yi;
+ UINT8 *gfx_rom = memregion("pcg")->base();
+
+ for(y=0;y<mc6845_v_display;y++)
+ {
+ for(x=0;x<mc6845_h_display;x++)
+ {
+ int tile = m_vram[x+y*mc6845_h_display] & 0xff;
+ int color = (m_vram[x+y*mc6845_h_display] & 0x700) >> 8;
+ int pen;
+
+ for(yi=0;yi<mc6845_tile_height;yi++)
+ {
+ for(xi=0;xi<8;xi++)
+ {
+ pen = (gfx_rom[tile*16+yi] >> (7-xi) & 1) ? color : 0;
+
+ if(y*mc6845_tile_height < 400 && x*8+xi < 640) /* TODO: safety check */
+ bitmap.pix16(y*mc6845_tile_height+yi, x*8+xi) = m_palette->pen(pen);
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+WRITE8_MEMBER( b16_state::b16_pcg_w )
+{
+ m_char_rom[offset] = data;
+
+ m_gfxdecode->gfx(0)->mark_dirty(offset >> 4);
+}
+
+static ADDRESS_MAP_START( b16_map, AS_PROGRAM, 16, b16_state)
+ ADDRESS_MAP_UNMAP_HIGH
+ AM_RANGE( 0x00000, 0x9ffff ) AM_RAM // probably not all of it.
+ AM_RANGE( 0xa0000, 0xaffff ) AM_RAM // bitmap?
+ AM_RANGE( 0xb0000, 0xb7fff ) AM_RAM AM_SHARE("vram") // tvram
+ AM_RANGE( 0xb8000, 0xbbfff ) AM_WRITE8(b16_pcg_w,0x00ff) // pcg
+ AM_RANGE( 0xfc000, 0xfffff ) AM_ROM AM_REGION("ipl",0)
+ADDRESS_MAP_END
+
+READ16_MEMBER( b16_state::vblank_r )
+{
+ return ioport("SYSTEM")->read();
+}
+
+WRITE8_MEMBER( b16_state::b16_6845_address_w )
+{
+ m_crtc_index = data;
+ m_mc6845->address_w(space,offset, data);
+}
+
+WRITE8_MEMBER( b16_state::b16_6845_data_w )
+{
+ m_crtc_vreg[m_crtc_index] = data;
+ m_mc6845->register_w(space, offset, data);
+}
+
+/*
+Pretty weird protocol, dunno what it is ...
+
+8a (06) W
+(04) R
+ff (04) W
+(04) R
+ff (04) W
+36 (0e) W
+ff (08) W
+ff (08) W
+06 (0e) W
+(08) R
+(08) R
+36 (0e) W
+40 (08) W
+9c (08) W
+76 (0e) W
+ff (0a) W
+ff (0a) W
+46 (0e) W
+(0a) R
+(0a) R
+76 (0e) W
+1a (0a) W
+00 (0a) W
+b6 (0e) W
+ff (0c) W
+ff (0c) W
+86 (0e) W
+(0c) R
+(0c) R
+b6 (0e) W
+34 (0c) W
+00 (0c) W
+36 (0e) W
+b6 (0e) W
+40 (08) W
+9c (08) W
+34 (0c) W
+00 (0c) W
+8a (06) W
+06 (06) W
+05 (06) W
+*/
+
+READ8_MEMBER( b16_state::unk_dev_r )
+{
+ static int test;
+
+ printf("(%02x) R\n",offset << 1);
+
+ if(offset == 0x8/2 || offset == 0x0a/2 || offset == 0x0c/2) // quick hack
+ {
+ test^=1;
+ return test ? 0x9f : 0x92;
+ }
+
+ return 0xff;
+}
+
+WRITE8_MEMBER( b16_state::unk_dev_w )
+{
+ printf("%02x (%02x) W\n",data,offset << 1);
+
+}
+
+static ADDRESS_MAP_START( b16_io, AS_IO, 16, b16_state)
+ ADDRESS_MAP_UNMAP_HIGH
+ AM_RANGE(0x00, 0x0f) AM_READWRITE8(unk_dev_r,unk_dev_w,0x00ff) // DMA device?
+ AM_RANGE(0x20, 0x21) AM_WRITE8(b16_6845_address_w,0x00ff)
+ AM_RANGE(0x22, 0x23) AM_WRITE8(b16_6845_data_w,0x00ff)
+ //0x79 bit 0 DSW?
+ AM_RANGE(0x80, 0x81) AM_READ(vblank_r) // TODO
+ADDRESS_MAP_END
+
+
+/* Input ports */
+static INPUT_PORTS_START( b16 )
+ PORT_START("SYSTEM")
+ PORT_BIT( 0x20, IP_ACTIVE_HIGH, IPT_CUSTOM ) PORT_VBLANK("screen")
+INPUT_PORTS_END
+
+
+
+
+static const gfx_layout b16_charlayout =
+{
+ 8, 16,
+ RGN_FRAC(1,1),
+ 1,
+ { 0 },
+ { STEP8(0,1) },
+ { STEP16(0,8) },
+ 8*16
+};
+
+static GFXDECODE_START( b16 )
+ GFXDECODE_ENTRY( "pcg", 0x0000, b16_charlayout, 0, 1 )
+GFXDECODE_END
+
+void b16_state::machine_start()
+{
+ m_mc6845 = machine().device<mc6845_device>("crtc");
+}
+
+void b16_state::machine_reset()
+{
+}
+
+
+READ8_MEMBER(b16_state::memory_read_byte)
+{
+ address_space& prog_space = m_maincpu->space(AS_PROGRAM);
+ return prog_space.read_byte(offset);
+}
+
+WRITE8_MEMBER(b16_state::memory_write_byte)
+{
+ address_space& prog_space = m_maincpu->space(AS_PROGRAM);
+ return prog_space.write_byte(offset, data);
+}
+
+
+static MACHINE_CONFIG_START( b16, b16_state )
+ /* basic machine hardware */
+ MCFG_CPU_ADD("maincpu",I8086, XTAL_14_31818MHz/2) //unknown xtal
+ MCFG_CPU_PROGRAM_MAP(b16_map)
+ MCFG_CPU_IO_MAP(b16_io)
+
+
+ /* video hardware */
+ MCFG_SCREEN_ADD("screen", RASTER)
+ MCFG_SCREEN_REFRESH_RATE(60)
+ MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500)) /* not accurate */
+ MCFG_SCREEN_UPDATE_DRIVER(b16_state, screen_update)
+ MCFG_SCREEN_SIZE(640, 400)
+ MCFG_SCREEN_VISIBLE_AREA(0, 640-1, 0, 400-1)
+ MCFG_SCREEN_PALETTE("palette")
+
+ MCFG_MC6845_ADD("crtc", H46505, "screen", XTAL_14_31818MHz/5) /* unknown clock, hand tuned to get ~60 fps */
+ MCFG_MC6845_SHOW_BORDER_AREA(false)
+ MCFG_MC6845_CHAR_WIDTH(8)
+
+ MCFG_DEVICE_ADD("8237dma", AM9517A, XTAL_14_31818MHz/2)
+ MCFG_I8237_IN_MEMR_CB(READ8(b16_state, memory_read_byte))
+ MCFG_I8237_OUT_MEMW_CB(WRITE8(b16_state, memory_write_byte))
+
+ MCFG_GFXDECODE_ADD("gfxdecode", "palette", b16)
+ MCFG_PALETTE_ADD("palette", 8)
+// MCFG_PALETTE_INIT_STANDARD(black_and_white) // TODO
+
+MACHINE_CONFIG_END
+
+/* ROM definition */
+ROM_START( b16 )
+ ROM_REGION( 0x4000, "ipl", ROMREGION_ERASEFF )
+ ROM_LOAD( "ipl.rom", 0x0000, 0x4000, CRC(7c1c93d5) SHA1(2a1e63a689c316ff836f21646166b38714a18e03) )
+
+ ROM_REGION( 0x4000/2, "pcg", ROMREGION_ERASE00 )
+ROM_END
+
+/* Driver */
+
+/* YEAR NAME PARENT COMPAT MACHINE INPUT INIT COMPANY FULLNAME FLAGS */
+COMP( 1983, b16, 0, 0, b16, b16, driver_device, 0, "Hitachi", "B16", MACHINE_NOT_WORKING | MACHINE_NO_SOUND)