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m92.c

0.36b6 [Bryan McPhail, Chris Hardy, Oliver Bergmann]


TODO:

- Gunforce: Animated water sometimes doesn't appear on level 5 (but it always appears if you cheat and jump straight to the level). Almost certainly a core bug.

- Irem Skins: Priority bug: you can't see the arrow on the top right map. Gfx problems at the players information during attract mode in Skins Game *only*, Major Title is fine (that part of attract mode is different). Eeprom load/save not yet implemented - when done, MT2EEP should be removed from the ROM definition.

- Perfect Soliders: Shortly into the fight, the sound CPU enters a tight loop, conitnuously writing to the status port and with interrupts disabled. I don't see how it is supposed to get out of that loop. Maybe it's not supposed to enter it at all?

- LeagueMan: Raster effects don't work properly (not even cpu time per line?).

- Dream Soccer 94: Slight priority problems when goal scoring animation is played.


NOTES:

- Driver: Emulation by Bryan McPhail. Thanks to Chris Hardy and Oliver Bergmann.

- Irem Skins Game has an eeprom and ticket payout(?). R-Type Leo & Lethal Thunder have a memory card.

- Many games use raster IRQ's for special video effects: Scrolling water in Undercover Cops and Score display in R-Type Leo. These are slow to emulate, and can be turned on/off by pressing F1 - they are on by default. These raster effects don't work in flipscreen mode.


VIDEO HARDWARE NOTES:

- The Irem M92 video hardware has 3 scrolling playfields (512x512). Each playfield can enable rowscroll, change shape (to 1024x512), be enabled/disabled and change position in VRAM. Tiles can have several priority values, Sprites have 2 priority values and Raster interrupts can be triggered at any line of the screen redraw, typically used in games like R-Type Leo to multiplex the top playfield.


Bugs:

- majtitl2, skingame, and skingam2: A problem with majtitl2, skingame, and skingam2, however, is sprite priority. This is most easily seen after finishing the first hole. The text in the middle of the screen is behind the trees in the background. The green is behind the text and the trees are behind the green. Listed in order that would mean that priorities are text, green, trees, text. Looping priorities! m92c053gre2 Abbe


WIP:

- 0.113: Zsolt Vasvari removed unnecessary idle skipping code from the m92 driver. This allows removal of a couple of now-unused functions from cpuexec.

- 0.106u3: Massive dipswitch update to the M92 driver [Brian Troha, Guru, Yasuhiro Ogawa].

- 0.99u7: Pierpaolo Prazzoli fixed tilemap-tilemap drawing order in M92 driver. Aaron Giles fixed the M92 state saving.

- 0.98u2: Aaron Giles replaced direct access to Machine->scrbitmap in the following drivers with the use of force_partial_update(): m92.c, m107.c, astrocde.c, battlera.c and snes.c.

- 0.66: Changed V33 CPU1 clock speed to 9MHz and V30 CPU2 to 7159090 Hz.

- 18th April 2002: Acho A. Tang improved the IREM GA-20 sound chip emulation which helps some of the games on the IREM M-92 hardware.

- 22nd January 2002: Bryan McPhail re-added Gunforce 2 to the IREM M-92 driver with some speedups.

- 11th January 2002: Acho A. Tang submitted a modification to the IREM GA20 sound chip emulation, which partially fixes some sample pitch problems in the IREM M-92 driver.

- 13th October 2001: Gerardo Oporto fixed some dipswitch settings in Irem M107 and M92 drivers.

- 0.55: Changed palettesize from 1024 to 2048 colors.

- 26th August 2001: Bryan McPhail improved the IREM M-92 driver, making Ninja Baseball Batman work.

- 0.53: Bryan McPhail and Nicola Salmoria decrypted the sound CPU in Gunforce, Blade Master, Lethal Thunder, Undercover Cops, Mystic Riders, Major Title 2, Hook, R-Type Leo, In the Hunt, and Perfect Soldiers.

- 25th July 2001: Marco Cassili fixed dipswitch settings in many M-92 games.

- 18th July 2001: Nicola Salmoria fixed several NEC CPU core bugs and errors in the IREM CPU decryption tables, and got sound working in Gunforce.

- 11th September 2000: Bryan McPhail sent in a huge Irem games update with a rewritten NEC core, fixing many bugs. R-Type Leo title screen was fixed as well as preliminary Irem GA20 custom sample player support was added.

- 29th April 2000: Bryan McPhail added the USA romset of In The Hunt to the M92 driver, and he fixed the slowdowns in V33 games.

- 18th January 2000: Bryan McPhail did some minor fixes to the M92 driver.

- 0.36b12: Changed V33 CPU1 clock speed to 18MHz.

- 3rd December 1999: Bryan McPhail sent in a M92 update with a few fixes to Gunforce and some speedups.

- 7th November 1999: Bryan McPhail added Perfect Soldiers to the M92 driver.

- 0.36b7: Changed V33 CPU1 clock speed to 20MHz.

- 9th October 1999: Bryan McPhail added Mystic Riders to the M92 driver (Gun Hohki World version).

- 29th September 1999: Bryan McPhail added Gun Hohki to the M92 driver.

- 0.36b6: Added m92.c driver.

- 27th September 1999: Nicola modified the M92 video driver to implement the tile priorities in another way.

- 24th September 1999: Oliver Bergmann sent in a NEC V20, V30, V33 cpu core, and Bryan McPhail submitted an Irem M92 driver with support for Blademaster, Gunforce, Lethal Thunder, Hook, Undercover Cops, R-type Leo, Major Title 2 and In The Hunt, but none of the games have sound because of an encrypted sound CPU.

- 31st May 1999: Nicola added Spelunker to the M62 driver.