diff options
Diffstat (limited to 'src/mame/video/gamate.cpp')
-rw-r--r-- | src/mame/video/gamate.cpp | 62 |
1 files changed, 31 insertions, 31 deletions
diff --git a/src/mame/video/gamate.cpp b/src/mame/video/gamate.cpp index 90b224f4034..02d82ab6b98 100644 --- a/src/mame/video/gamate.cpp +++ b/src/mame/video/gamate.cpp @@ -2,26 +2,26 @@ // copyright-holders:David Haywood, Peter Wilhelmsen, Kevtris /* - Notes: + Notes: - Some games are glitchy, most of these glitches are verified to happen on hardware - for example + Some games are glitchy, most of these glitches are verified to happen on hardware + for example - Badly flipped sprites in Tornado and Insect War - Heavy flickering sprites in many games + Badly flipped sprites in Tornado and Insect War + Heavy flickering sprites in many games - Most of these issues are difficult to notice on real hardware due to the poor - quality display. + Most of these issues are difficult to notice on real hardware due to the poor + quality display. - Thanks to Kevtris for the documentation on which this implementation is based - (some comments taken directly from this) - http://blog.kevtris.org/blogfiles/Gamate%20Inside.txt + Thanks to Kevtris for the documentation on which this implementation is based + (some comments taken directly from this) + http://blog.kevtris.org/blogfiles/Gamate%20Inside.txt - ToDo: + ToDo: - Emulate vram pull / LCD refresh timings more accurately. - Interrupt should maybe be in here, not in drivers/gamate.cpp? - Verify both Window modes act the same as hardware. + Emulate vram pull / LCD refresh timings more accurately. + Interrupt should maybe be in here, not in drivers/gamate.cpp? + Verify both Window modes act the same as hardware. */ #include "emu.h" @@ -125,7 +125,7 @@ WRITE8_MEMBER(gamate_video_device::xpos_w) /* BxxX XXXX B: Bitplane. 0 = lower (bitplane 0), 1 = upper (bitplane 1) - X: 5 lower bits of the 13 bit VRAM address. + X: 5 lower bits of the 13 bit VRAM address. */ m_bitplaneselect = (data & 0x80) >> 7; set_vram_addr_lower_5bits(data & 0x1f); @@ -135,7 +135,7 @@ WRITE8_MEMBER(gamate_video_device::ypos_w) { /* YYYY YYYY - Y: 8 upper bits of 13 bit VRAM address. + Y: 8 upper bits of 13 bit VRAM address. */ set_vram_addr_upper_8bits(data); } @@ -170,13 +170,13 @@ void gamate_video_device::get_real_x_and_y(int &ret_x, int &ret_y, int scanline) { /* the Gamate video has 2 'Window' modes, Mode 1 is enabled with an actual register - Mode 2 is enabled automatically based on the yscroll value - + Mode 2 is enabled automatically based on the yscroll value + both modes seem designed to allow for a non-scrolling status bar at the top of the display. */ - if (m_scrolly < 0xc8) + if (m_scrolly < 0xc8) { ret_y = scanline + m_scrolly; @@ -199,8 +199,8 @@ void gamate_video_device::get_real_x_and_y(int &ret_x, int &ret_y, int scanline) ret_x = m_scrollx; /* - Using Yscroll values of C8-CF, D8-DF, E8-EF, and F8-FF will result in the same - effect as if a Yscroll value of 00h were used. + Using Yscroll values of C8-CF, D8-DF, E8-EF, and F8-FF will result in the same + effect as if a Yscroll value of 00h were used. */ if (m_scrolly & 0x08) // values of C8-CF, D8-DF, E8-EF, and F8-FF { @@ -210,13 +210,13 @@ void gamate_video_device::get_real_x_and_y(int &ret_x, int &ret_y, int scanline) else { /* - Values D0-D7, E0-E7, and F0-F7 all produce a bit more useful effect. The upper - 1-8 scanlines will be pulled from rows F8-FFh in VRAM (i.e. 1F00h = row F8h). + Values D0-D7, E0-E7, and F0-F7 all produce a bit more useful effect. The upper + 1-8 scanlines will be pulled from rows F8-FFh in VRAM (i.e. 1F00h = row F8h). - If F0 is selected, then the upper 8 rows will be the last 8 rows in VRAM- - 1F00-1FFFh area. If F1 is selected, the upper 8 rows will be the last 7 rows - in VRAM and so on. This special window area DOES NOT SCROLL with X making it - useful for status bars. I don't think any games actually used it, though. + If F0 is selected, then the upper 8 rows will be the last 8 rows in VRAM- + 1F00-1FFFh area. If F1 is selected, the upper 8 rows will be the last 7 rows + in VRAM and so on. This special window area DOES NOT SCROLL with X making it + useful for status bars. I don't think any games actually used it, though. */ int fixedscanlines = m_scrolly & 0x7; @@ -232,7 +232,7 @@ void gamate_video_device::get_real_x_and_y(int &ret_x, int &ret_y, int scanline) ret_y = scanline;// +m_scrolly; //if (ret_y >= 0xc8) - // ret_y -= 0xc8; + // ret_y -= 0xc8; } } @@ -299,9 +299,9 @@ PALETTE_INIT_MEMBER(gamate_video_device, gamate) } /* - Of the 150 scanlines emitted, all contain pixel data pulled from RAM. There are - exactly 72900 clocks per frame, so at the nominal 4.433MHz rate, this means the - frame rate is 60.8093Hz. + Of the 150 scanlines emitted, all contain pixel data pulled from RAM. There are + exactly 72900 clocks per frame, so at the nominal 4.433MHz rate, this means the + frame rate is 60.8093Hz. */ MACHINE_CONFIG_MEMBER( gamate_video_device::device_add_mconfig ) |