[MAME]

Sega System24 Overview
Sega, 1987-1994

PCB Layout
----------

Note: The differences in the revisions is just the use of different sized RAMs
and the quantities of RAM used.

(1st Revision)
837-6442 SYSTEM 24 (C)SEGA 1987
|-------------------------------------------------------------------------------|
| YM2151 DSW1 EPRxxxxx.IC1           --------------------------| TMM41464-10    |
|          DSW2         EPRxxxxx.IC2 |-------------------------- TMM41464-10    |
|                                                CN2             TMM41464-10    |
|                 68000               |---------|                TMM41464-10    |
|   |---------|  |--------------|     | 315-5295|                TMM41464-10    |
|   | 315-5296|  |HITACHI FD1094|     |(QFP100) |                TMM41464-10    |
|-| |(QFP100) |  |317-0xxx-0xx  |     |         |                TMM41464-10    |
  | |         |  |--------------|     |---------|                TMM41464-10    |
|-| |---------|                                                  MB81C466-10    |
|                                                                MB81C466-10    |
|                                     |---------|                MB81C466-10    |
|S                        |---------| | 315-5295|                MB81C466-10    |
|E                 20MHz  | 315-5295| |(QFP100) |                MB81C466-10    |
|G                        |(QFP100) | |         |                MB81C466-10    |
|A                        |         | |---------|                MB81C466-10    |
|                         |---------|                            MB81C466-10    |
|5                                                               |---------|    |
|6                       |---------|  |---------|                | 315-5293|    |
|                        | 315-5294|  | 315-5292|                | (QFP160)|    |
|                        |(QFP100) |  | (QFP160)|    32MHz       |         |    |
|            MB81C78A-45 |         |  |         |                |---------|    |
|-|          MB81C78A-45 |---------|  |---------|M5M4464-12 x4   MB81461-12 x6  |
  |                                                                             |
|-|      YM3012                                                                 |
|            |--------|                                                         |
|            |315-5242| HM65256 HM65256 HM65256  M5M4464-12 x4   MB81461-12 x6  |
|            |(QFP44) | HM65256 HM65256 HM65256                                 |
|------------|--------|---------------------------------------------------------|


(2nd Revision)
837-6442-01 SYSTEM 24 (C) SEGA 1987
|-------------------------------------------------------------------------------|
| YM2151 DSW1 EPRxxxxx.IC1           --------------------------| TMM41464-10    |
|          DSW2         EPRxxxxx.IC2 |-------------------------- TMM41464-10    |
|                                                CN2             TMM41464-10    |
|                 68000               |---------|                TMM41464-10    |
|   |---------|  |--------------|     | 315-5295|                TMM41464-10    |
|   | 315-5296|  |HITACHI FD1094|     |(QFP100) |                TMM41464-10    |
|-| |(QFP100) |  |317-0xxx-0xx  |     |         |                TMM41464-10    |
  | |         |  |--------------|     |---------|                TMM41464-10    |
|-| |---------|                                                  TMM41464-10    |
|                                                                TMM41464-10    |
|                                     |---------|                TMM41464-10    |
|S                        |---------| | 315-5295|                TMM41464-10    |
|E                 20MHz  | 315-5295| |(QFP100) |                TMM41464-10    |
|G                        |(QFP100) | |         |                TMM41464-10    |
|A                        |         | |---------|                TMM41464-10    |
|                         |---------|                            TMM41464-10    |
|5                                                               |---------|    |
|6                       |---------|  |---------|                | 315-5293|    |
|                        | 315-5294|  | 315-5292|                | (QFP160)|    |
|                        |(QFP100) |  | (QFP160)|    32MHz       |         |    |
|            MB81C78A-45 |         |  |         |                |---------|    |
|-|          MB81C78A-45 |---------|  |---------|M5M4464-12 x4   MB81461-12 x6  |
  |                                                                             |
|-|      YM3012                                (*)                              |
|            |--------|                                                         |
|            |315-5242| HM65256 HM65256 HM65256  M5M4464-12 x4   MB81461-12 x6  |
|            |(QFP44) | HM65256 HM65256 HM65256                                 |
|------------|--------|---------------------------------------------------------|
(*) Unpopulated Sockets for MB81C4256 x4


(3rd Revision)
837-6442-02 SYSTEM 24 (C) SEGA 1987
|-------------------------------------------------------------------------------|
| YM2151 DSW1 EPRxxxxx.IC1           --------------------------| TC514256-10    |
|          DSW2         EPRxxxxx.IC2 |-------------------------- TC514256-10    |
|                                                CN2             TC514256-10    |
|                 68000               |---------|                TC514256-10    |
|   |---------|  |--------------|     | 315-5295|                TC514256-10    |
|   | 315-5296|  |HITACHI FD1094|     |(QFP100) |                TC514256-10    |
|-| |(QFP100) |  |317-0xxx-0xx  |     |         |                TC514256-10    |
  | |         |  |--------------|     |---------|                TC514256-10    |
|-| |---------|                                                                 |
|                                                                               |
|                                     |---------|                               |
|S                        |---------| | 315-5295|                               |
|E                 20MHz  | 315-5295| |(QFP100) |                               |
|G                        |(QFP100) | |         |                               |
|A                        |         | |---------|                               |
|                         |---------|                                           |
|5                                                               |---------|    |
|6                       |---------|  |---------|                | 315-5293|    |
|                        | 315-5294|  | 315-5292|                | (QFP160)|    |
|                        |(QFP100) |  | (QFP160)|    32MHz       |         |    |
|            MB81C78A-45 |         |  |         |                |---------|    |
|-|          MB81C78A-45 |---------|  |---------|                MB81461-12 x6  |
  |                                                                             |
|-|      YM3012                                                                 |
|            |--------|                                                         |
|            |315-5242| HM65256 HM65256 TC51832  TC514256-10 x4  MB81461-12 x6  |
|            |(QFP44) | HM65256 HM65256 TC51832                                 |
|------------|--------|---------------------------------------------------------|
Notes:
               315-5292: Custom Sega IC (QFP160, Tilemap Generator)
               315-5293: Custom Sega IC (QFP160, Object Generator)
               315-5294: Custom Sega IC (QFP100, Mixer Chip)
               315-5295: Custom Sega IC (QFP100, Object Generator)
               315-5296: Custom Sega IC (QFP100, I/O Chip)
               315-5242: Custom Sega IC (QFP44, Colour Encoder)
            68000 clock: 10.000MHz
   Hitachi FD1094 clock: 10.000MHz
           YM2151 clock: 4.000MHz
                  VSync: 58Hz
                  HSync: 24.33kHz (All System24 games require 24kHz monitor)
        CN2 (Above PCB): Connector for ROM Board (Not used for floppy-based games)
        CN2 (Below PCB): Connector for Floppy Controller Board (Not used for ROM-based games)
        Main PCB Pinout same as System 16
        Floppy Drive is a standard 1.44 High Density drive, but the controller is custom and
        the floppy disk format is custom. The floppy disk can be read with "Anadisk"
        depending on the PC being used and it's floppy controller. Most clone PC's can't read the
        System 24 floppies even with "Anadisk"[1]. But many brand-name PC's can. It's likely due to the
        propietry nature of the components used in brand-name PC's. Generally the older and crappier
        the PC is, the better chance you have of being able to read the floppy ;-)

        [1] Actually, most can _except_ for the Hotrod disks.  Those 8K sectors are deadly.


Floppy Controller PCB Layout
----------------------------

837-6443         ___________
|---------------|    DATA   |-- ||||---|
|                               PWR    |
|     74LS367 74LS05                   |
|     74LS367 74LS174                  |
|                     MB4107   74LS05  |
|                                      |
|     MB89311         74LS139   8MHz   |
|                CN1                   |
|     --------------------------|      |
|     |--------------------------      |
|--------------------------------------|


I/O Controller PCB Layout
-------------------------

834-6510
(sticker 834-6510-01)   ___________
|----------------------|  IDC 34   |---|
|                                      |
|                                      |
|  D4701          %2                   |
|                                      |
|                 %3                   |
|    %1                       74LS139  |
|                CN1                   |
|     --------------------------|      |
|     |--------------------------      |
|--------------------------------------|
Notes:
      - %1 - Unpopulated position for D4701 IC
        %2 - Unpopulated position for MSM6253RS IC
        %3 - Unpopulated position for MSM6253RS IC

      - CN1 is shown for completeness, it's actually underneath the I/O PCB.

      - The custom I/O board plugs into the top connector on the main board and
        is used for player steering controls. The wiring diagram has 8 pins coming from
        the connector. Four are labelled 'JST4P 1P (L)', the other four are labelled
        'JST4P 2P (R)'. I assume this is for an analog wheel or similar for player 1
        (being on the left) and player 2 (being on the right)
        The wiring diagram also lists some buttons for both PL1 and PL2 coming from
        the regular 56-way edge connector....  'Nitro' and 'Accel'
        The manual shows a controller that looks like a spinner which they call
        a 'sensor board' with part 839-0138 and has a photo-sensor disc, which looks
        like it's used for steering.
        This board is used on Hot Rod, Rough Racer and the Golf games only.


ROM Board Layout
----------------

837-7187-01
171-5875-01B
(SYSTEM24) (C)SEGA 1989 . 1991
|------------------------------------------|
|                                          |
|                                          |
|                                  J1      |
|CN1    ROM1.IC4      ROM2.IC5     J2      |
||-|                               J3      |
|| |                               J4      |
|| |    ROM3.IC6      ROM4.IC7             |
|| |                               J5      |
|| |                               J6      |
|| |    ROM5.IC8      ROM6.IC9     J7      |
|| |                               J8      |
|| |                               J9      |
|| |    ROM7.IC10     ROM8.IC11            |
|| |                                       |
|| |                  74HC4040  74LS139    |
||-|    EPM5032DC.IC2                      |
|------------------------------------------|
Notes:
      CN1: Connector for joining ROM board to Main Board. This connector is above and below the PCB to allow for chaining of several boards.

      The ROM Daughter board has a protection device on it at location IC2. It's an Erasable Programmable Logic Device; EPLD, like a normal PLD,
      but uses an EPROM and is erasable and re-programmable. It's type is Altera EPM5032DC. It's part of the Altera MAX 5000 Programmable Logic
      Device Family and (generally) has it's protection bit set at the factory.

      All jumpers are 2 pins, they're either shorted or not shorted. All ROMs are configured as the same type.
      See the table below for details.
      Jumpers to set ROM sizes:
                               2M (J1, J3, J6, J8)
                               4M (J2, J3, J7, J9)
                               8M (J2, J4, J5, J9)


FD1094/Floppy/ROM details
-------------------------

Game                   FD1094         Floppy          ROMs                                                          Other
-------------------------------------------------------------------------------------------------------------------------------------------------------------
Hot Rod (3p Turbo)     none           DS3-5000-01D    Main Board:     EPR11338.IC1, EPR11339.IC2                    I/O Controller PCB, Floppy Controller PCB

Hot Rod (4p Rev C)     none           DS3-5000-01A    Main Board:     EPR11338.IC1, EPR11339.IC2                    I/O Controller PCB, Floppy Controller PCB
                                      Rev C

Hot Rod (4p Japanese   none           DS3-5000-01A    Main Board:     EPR11338.IC1, EPR11339.IC2                    I/O Controller PCB, Floppy Controller PCB
         Rev B)                       Rev B

Scramble Spirits       none           DS3-5000-02?    Main Board:     EPR12186.IC1, EPR12187.IC2                    Floppy Controller PCB

Scramble Spirits       317-0058-02D   DS3-5000-02D    Main Board:     EPR12186.IC1, EPR12187.IC2                    Floppy Controller PCB
(Encrypted Version)

Gain Ground (Japan)    317-0058-03B   DS3-5000-03B    Main Board:     EPR12186.IC1, EPR12187.IC2                    Floppy Controller PCB

Gain Ground            317-0058-03D   DS3-5000-03D    Main Board:     EPR12186.IC1, EPR12187.IC2                    Floppy Controller PCB

Crack Down (Japan)     317-0058-04B   DS3-5000-04B    Main Board:     EPR12186.IC1, EPR12187.IC2                    Floppy Controller PCB
                                      Rev A

Crack Down             317-0058-04D   DS3-5000-04D    Main Board:     EPR12186.IC1, EPR12187.IC2                    Floppy Controller PCB

Super Masters Golf     317-0058-05B   DS3-5000-05B    Main Board:     EPR12186.IC1, EPR12187.IC2                    I/O Controller PCB, Floppy Controller PCB
Rev B

Super Masters Golf     317-0058-05D   DS3-5000-05D    Main Board:     EPR12186.IC1, EPR12187.IC2                    I/O Controller PCB, Floppy Controller PCB
Rev D

Rough Racer            317-0058-06B   DS3-5000-06B    Main Board:     EPR12186.IC1, EPR12187.IC2                    I/O Controller PCB, Floppy Controller PCB

Bonanza Bros           none           DS3-5000-07D    Main Board:     EPR12186.IC1, EPR12187.IC2                    Floppy Controller PCB
                                                      Daughter Board: MPR13187.IC4, MPR13188.IC5, MPR13189.IC6
                                                                      MPR13190.IC7
                                                                      EPLD: 317-0156

Quiz Syukudai wo       317-0058-08B   DS3-5000-08B    Main Board:     EPR12186.IC1, EPR12187.IC2                    Floppy Controller PCB
Wasuremashita

Dynamic Country Club   317-0058-09D   DS3-5000-09D    Main Board:     EPR13947.IC1, EPR13948.IC2                    I/O Controller PCB, Floppy Controller PCB
(Disk version)

Dynamic Country Club   none           none            Main Board:     EPR13947.IC1, EPR13948.IC2
(ROM version)                                         Daughter Board: EPR15345.IC4  EPR15344.IC5, MPR14097.IC6
                                                                      MPR14096.IC7
                                                                      EPLD: 317-0177

Quiz Mekuromeku Story  none           none            Main Board:     EPR15342.IC1, EPR15343.IC2
                                                      Daughter Board: EPR15344.IC4, EPR15345.IC5, EPR15346.IC6
                                                                      EPR15347.IC7, EPR15348.IC8, EPR15349.IC9
                                                                      EPLD: 317-0205

Tokoro San no          none           none            Main Board:     EPR14812.IC1, EPR14813.IC2
MahMahjan                                             Daughter Board: MPR14819.IC4, MPR14820.IC5, MPR14821.IC6
                                                                      MPR14822IC.7, MPR14823.IC8, MPR14824.IC9
                                                                      MPR14825.IC10, MPR14826.IC11
                                                                      EPLD: 317-0200

Quiz Rouka Ni          none           none            Main Board:     EPR14484.IC1, EPR14485.IC2
Tattenasai                                            Daughter Board: EPR14482.IC5, EPR14483.IC7
                                                                      EPLD: 317-0191

Tokoro San no          none           none            Main Board:     EPR16798.IC1, EPR16799.IC2
MahMahjan 2                                           Daughter Board: MPR16800.IC4, MPR16801.IC5, MPR16802.IC6
                                                                      MPR16803.IC7, MPR16804.IC8, MPR16805.IC9
                                                                      MPR16806.IC10, MPR16807.IC11
                                                                      EPLD: 317-0220

Quiz Ghost Hunter      none           none            Main Board:     EPR16899B.IC1, EPR16900B.IC2
                                                      Daughter Board: MPR16901A.IC4, MPR16902A.IC5, MPR16903.IC6
                                                                      MPR16904.IC7,  MPR16905.IC8,  MPR16906.IC9
                                                                      MPR16907.IC10,  MPR16908.IC11
                                                                      EPLD: 317-0226

Notes:
      A regular 68000-10 is used in position IC3. If used, the Hitachi CPU sits at position IC4.
      Where FD1094 is listed as 'none', a standard 68000 CPU is used instead at IC4 on the PCB.

      The last 3 digits of the floppy number is also the last part of the Hitachi CPU number....they're a matching pair.
      So if one had the Hitachi part number and a floppy without a label, it's possible to create the correct floppy disk name from

-

[MAME - older info]

PCB Layout
----------

837-6442 SYSTEM 24 (C) SEGA 1987
|-------------------------------------------------------------------------------|
| YM2151 DSW1 EPR12186.IC1           --------------------------| TMM41464-10 x4 |
|          DSW2         EPR12187.IC2 |--------------------------                |
|                                                CN2                            |
|                 68000                                          TMM41464-10 x4 |
|                |--------------|      315-5295                                 |
|    315-5296    |HITACHI FD1094|      (QFP100)                                 |
|-|  (QFP100)    |317-0058-03D  |                                               |
  |              |--------------|                                               |
|-|                                                              MB81C466-10 x4 |
|                                                                               |
|                                                                               |
|S                                     315-5295                                 |
|E                 20MHz   315-5195    (QFP100)                  MB81C466-10 x4 |
|G                         (QFP100)                                             |
|A                                                                              |
|                                                                               |
|5                                                                              |
|6                                                                              |
|                       315-5294        315-5292                  315-5293      |
|                       (QFP100)        (QFP160)     32MHz        (QFP160)      |
|            MB81C78A-45                                                        |
|-|          MB81C78A-45                         M5M4464-12 x4   MB81461-12 x6  |
  |                                                                             |
|-|      YM3012                                                                 |
|                                                                               |
|             315-5242  HM65256 HM65256 HM65256  M5M4464-12 x4   MB81461-12 x6  |
|             (QFP44)   HM65256 HM65256 HM65256                                 |
|-------------------------------------------------------------------------------|


Floppy Controller PCB Layout
----------------------------


837-6443         ___________
|---------------|    DATA   |-- ||||---|
|                               PWR    |
|     74LS367 74LS05                   |
|     74LS367 74LS174                  |
|                     MB4107   74LS05  |
|                                      |
|     MB89311         74LS139   8MHz   |
|                CN1                   |
|     --------------------------|      |
|     |--------------------------      |
|--------------------------------------|


Notes:
            68000 clock: 10.000MHz
   Hitachi FD1094 clock: 10.000MHz
           YM2151 clock: 4.000MHz
                  VSync: 58Hz
                  HSync: 24.33kHz (game requires 24kHz monitor)
        CN2 (Above PCB): Connector for ROM Board (Not used for Gain Ground)
        CN2 (Below PCB): Connector for Floppy Controller Board
        PCB Pinout same as System 16
        Floppy Drive is a standard 1.44 High Density drive, but the controller
        is custom and the floppy disk format is custom. The floppy disk can be read with "Anadisk"
        depending on the PC being used and its floppy controller. Mostly, PC's can't read the System 24
        floppies even with "Anadisk"[1]

  [1] Actually, most can _except_ for the hotrod disks.  Those 8K sectors are deadly.

-