diff options
Diffstat (limited to 'src/mame/video/galaxy.c')
-rw-r--r-- | src/mame/video/galaxy.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/src/mame/video/galaxy.c b/src/mame/video/galaxy.c new file mode 100644 index 00000000000..0f8184916f8 --- /dev/null +++ b/src/mame/video/galaxy.c @@ -0,0 +1,134 @@ +// license:BSD-3-Clause +// copyright-holders:Krzysztof Strzecha, Miodrag Milanovic +/*************************************************************************** + + galaxy.c + + Functions to emulate the video hardware of the Galaksija. + + 20/05/2008 - Real video implementation by Miodrag Milanovic + 01/03/2008 - Update by Miodrag Milanovic to make Galaksija video work with new SVN code +***************************************************************************/ + +#include "emu.h" +#include "includes/galaxy.h" +#include "cpu/z80/z80.h" + + +TIMER_CALLBACK_MEMBER(galaxy_state::gal_video) +{ + address_space &space = m_maincpu->space(AS_PROGRAM); + int y, x; + if (m_interrupts_enabled == TRUE) + { + UINT8 *gfx = m_region_gfx1->base(); + UINT8 dat = (m_latch_value & 0x3c) >> 2; + if ((m_gal_cnt >= 48 * 2) && (m_gal_cnt < 48 * 210)) // display on screen just m_first 208 lines + { + UINT8 mode = (m_latch_value >> 1) & 1; // bit 2 latch represents mode + UINT16 addr = (m_maincpu->state_int(Z80_I) << 8) | m_maincpu->state_int(Z80_R) | ((m_latch_value & 0x80) ^ 0x80); + if (mode == 0) + { + // Text mode + if (m_first == 0 && (m_maincpu->state_int(Z80_R) & 0x1f) == 0) + { + // Due to a fact that on real processor latch value is set at + // the end of last cycle we need to skip dusplay of double + // m_first char in each row + m_code = 0x00; + m_first = 1; + } + else + { + m_code = space.read_byte(addr) & 0xbf; + m_code += (m_code & 0x80) >> 1; + m_code = gfx[(m_code & 0x7f) +(dat << 7 )] ^ 0xff; + m_first = 0; + } + y = m_gal_cnt / 48 - 2; + x = (m_gal_cnt % 48) * 8; + + m_bitmap.pix16(y, x ) = (m_code >> 0) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 1) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 2) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 3) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 4) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 5) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 6) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 7) & 1; + } + else + { // Graphics mode + if (m_first < 4 && (m_maincpu->state_int(Z80_R) & 0x1f) == 0) + { + // Due to a fact that on real processor latch value is set at + // the end of last cycle we need to skip dusplay of 4 times + // m_first char in each row + m_code = 0x00; + m_first++; + } + else + { + m_code = space.read_byte(addr) ^ 0xff; + m_first = 0; + } + y = m_gal_cnt / 48 - 2; + x = (m_gal_cnt % 48) * 8; + + /* hack - until calc of R is fixed in Z80 */ + if (x == 11 * 8 && y == 0) + { + m_start_addr = addr; + } + if ((x / 8 >= 11) && (x / 8 < 44)) + { + m_code = space.read_byte(m_start_addr + y * 32 + (m_gal_cnt % 48) - 11) ^ 0xff; + } + else + { + m_code = 0x00; + } + /* end of hack */ + + m_bitmap.pix16(y, x ) = (m_code >> 0) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 1) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 2) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 3) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 4) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 5) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 6) & 1; x++; + m_bitmap.pix16(y, x ) = (m_code >> 7) & 1; + } + } + m_gal_cnt++; + } +} + +void galaxy_state::galaxy_set_timer() +{ + m_gal_cnt = 0; + m_gal_video_timer->adjust(attotime::zero, 0, attotime::from_hz(6144000 / 8)); +} + +void galaxy_state::video_start() +{ + m_gal_cnt = 0; + + m_gal_video_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(galaxy_state::gal_video),this)); + m_gal_video_timer->adjust(attotime::zero, 0, attotime::never); + + machine().first_screen()->register_screen_bitmap(m_bitmap); +} + +UINT32 galaxy_state::screen_update_galaxy(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect) +{ + m_gal_video_timer->adjust(attotime::zero, 0, attotime::never); + if (m_interrupts_enabled == FALSE) + { + const rectangle black_area(0, 384 - 1, 0, 208 - 1); + m_bitmap.fill(0, black_area); + } + m_interrupts_enabled = FALSE; + copybitmap(bitmap, m_bitmap, 0, 0, 0, 0, cliprect); + return 0; +} |