Irem M84 Conversions

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    • Conversions are possible however you can only convert games with the same bottom board as sound hardware is quite different.
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • To be confirmed but to me games can be grouped as follow:
      - R-Type II, Major Title
      - Ken-Go, Hammerin' Harry, Cosmic Cop
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • Humm...
      It seems I was mistaken somehow.

      According to MAME:

      MAME wrote:

      M84-A-A (bottom board) (most games)
      ...
      M84-D-B (bottom board) (found on lightning swords / kengo)

      MAME wrote:

      // M84// is the upd71059c present and unused, or has it been removed from the PCB? it isn't needed beacuse the V35 has it's own IRQ controller.
      static MACHINE_CONFIG_START( cosmccop, m72_state )
      /* basic machine hardware */
      MCFG_CPU_ADD("maincpu", V35,MASTER_CLOCK/2)
      MCFG_CPU_PROGRAM_MAP(kengo_map)

      Although sound hardware is different I'm not sure it makes a difference from a software point of view.

      If so then any M84 game can be converted to any M72/M81/M82/M85 game.
      Painful part is ROMs are mostly soldered.
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • acblunden2 wrote:


      I'l order the EPROM's and follow this conversion guide for my Hammerin' Harry board and let you know how it goes.
      I've never done this conversion but I've always wondered why there was wire patching involved. Isn't it possible to do no wire hack at all by handcrafting the appropriate PAL?
      Or is it an other hardware limitation I don't get yet (missing address lines?).
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • Apocalypse wrote:

      I've never done this conversion but I've always wondered why there was wire patching involved. Isn't it possible to do no wire hack at all by handcrafting the appropriate PAL?Or is it an other hardware limitation I don't get yet (missing address lines?).
      That is Greek to me my friend =). I'll give the conversion a shot anyway. I won't cut the trace as suggested though. I'll lift the ERPROM leg and run Kynar wire to the point to preserve the board. If all is well, great! Dig deeper from there if needed.

      It is going to take a good 3 weeks for the EPROM's to get here. I have the dip sockets already. Can't wait!
    • acblunden2 wrote:

      Apocalypse wrote:

      I've never done this conversion but I've always wondered why there was wire patching involved. Isn't it possible to do no wire hack at all by handcrafting the appropriate PAL?Or is it an other hardware limitation I don't get yet (missing address lines?).
      That is Greek to me my friend =). I'll give the conversion a shot anyway. I won't cut the trace as suggested though. I'll lift the ERPROM leg and run Kynar wire to the point to preserve the board. If all is well, great! Dig deeper from there if needed.
      It is going to take a good 3 weeks for the EPROM's to get here. I have the dip sockets already. Can't wait!
      Good news! Let us know how it goes and take some pics please :)
      * Arcade-projects, the site where you get the most of your arcade games.
      * If you want Drama go to Neo-Geo forum ---Darksoft
    • acblunden2 wrote:

      Apocalypse wrote:

      I've never done this conversion but I've always wondered why there was wire patching involved. Isn't it possible to do no wire hack at all by handcrafting the appropriate PAL?Or is it an other hardware limitation I don't get yet (missing address lines?).
      That is Greek to me my friend =). I'll give the conversion a shot anyway. I won't cut the trace as suggested though. I'll lift the ERPROM leg and run Kynar wire to the point to preserve the board. If all is well, great! Dig deeper from there if needed.
      It is going to take a good 3 weeks for the EPROM's to get here. I have the dip sockets already. Can't wait!
      If you get tired of waiting you could always socket your original ROMs in the meantime. :D
    • acblunden2 wrote:

      Apocalypse wrote:

      I've never done this conversion but I've always wondered why there was wire patching involved. Isn't it possible to do no wire hack at all by handcrafting the appropriate PAL?Or is it an other hardware limitation I don't get yet (missing address lines?).
      That is Greek to me my friend =). I'll give the conversion a shot anyway. I won't cut the trace as suggested though. I'll lift the ERPROM leg and run Kynar wire to the point to preserve the board. If all is well, great! Dig deeper from there if needed.
      It is going to take a good 3 weeks for the EPROM's to get here. I have the dip sockets already. Can't wait!
      It seems IC7 is a 32kB RAM.
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • Apocalypse wrote:

      acblunden2 wrote:

      Apocalypse wrote:

      I've never done this conversion but I've always wondered why there was wire patching involved. Isn't it possible to do no wire hack at all by handcrafting the appropriate PAL?Or is it an other hardware limitation I don't get yet (missing address lines?).
      That is Greek to me my friend =). I'll give the conversion a shot anyway. I won't cut the trace as suggested though. I'll lift the ERPROM leg and run Kynar wire to the point to preserve the board. If all is well, great! Dig deeper from there if needed.It is going to take a good 3 weeks for the EPROM's to get here. I have the dip sockets already. Can't wait!
      It seems IC7 is a 32kB RAM.
      I wonder what cutting that trace does then? If it is just 32kB RAM, how does running it to a capacitor at C36 do anything? This is all Greek to me so I am probably making an ass out of myself even by asking.
    • acblunden2 wrote:

      I wonder what cutting that trace does then? If it is just 32kB RAM, how does running it to a capacitor at C36 do anything? This is all Greek to me so I am probably making an ass out of myself even by asking.
      C36 is just a point where you can find ground I guess.
      Top left pin is A14 so grounding it means you use only the lower part of the RAM.
      I had a look in MAME and discovered M82 has twice much video RAM 2 than M72:

      MAME wrote:

      static ADDRESS_MAP_START( m82_map, AS_PROGRAM, 16, m72_state )
      AM_RANGE(0x00000, 0x7ffff) AM_ROM
      AM_RANGE(0xa0000, 0xa03ff) AM_RAM AM_SHARE("majtitle_rowscr")
      AM_RANGE(0xa4000, 0xa4bff) AM_READWRITE(palette2_r, palette2_w) AM_SHARE("paletteram2")
      AM_RANGE(0xac000, 0xaffff) AM_RAM_WRITE(videoram1_w) AM_SHARE("videoram1")
      AM_RANGE(0xb0000, 0xbffff) AM_RAM_WRITE(videoram2_w) AM_SHARE("videoram2") /* larger than the other games */
      AM_RANGE(0xc0000, 0xc03ff) AM_RAM AM_SHARE("spriteram")
      AM_RANGE(0xc8000, 0xc83ff) AM_RAM AM_SHARE("spriteram2")
      AM_RANGE(0xcc000, 0xccbff) AM_READWRITE(palette1_r, palette1_w) AM_SHARE("paletteram")
      AM_RANGE(0xd0000, 0xd3fff) AM_RAM /* work RAM */
      AM_RANGE(0xe0000, 0xe0001) AM_WRITE(irq_line_w)
      AM_RANGE(0xe4000, 0xe4001) AM_WRITEONLY /* playfield enable? 1 during screen transitions, 0 otherwise */
      AM_RANGE(0xec000, 0xec001) AM_WRITE(dmaon_w)
      AM_RANGE(0xffff0, 0xfffff) AM_ROM
      ADDRESS_MAP_END

      Still I wonder if it wouldn't be possible to accommodate that with code modifications.
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • Apocalypse wrote:

      C36 is just a point where you can find ground I guess.
      Top left pin is A14 so grounding it means you use only the lower part of the RAM.
      I see. Makes great logical sense. I learned something here.

      Apocalypse wrote:

      Still I wonder if it wouldn't be possible to accommodate that with code modifications.
      Don't sweat it for now Boss. I'll follow that guide categorically and see how it goes. I will report back what I find.
    • stj wrote:

      bastards.

      the only reason to make half the ram mirror itself is if they are acessing it at different banks for protection.
      No protection on R-Type. Actually it's the only M72 game not equipped with a MCU for protection.
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • @Apocalypse so from All these MXX boards which one is in your opinion the preferred. I mean the one that could accomodate more games because of the amount of RAM and availabilty? M82?
      * Arcade-projects, the site where you get the most of your arcade games.
      * If you want Drama go to Neo-Geo forum ---Darksoft