List of Games Using the EXT Port

The below is detailed information on the EXT Port:

• Availability of the EXT port between various Sega Genesis-based console models and revisions
• Hardware mods to restore the EXT port
• List of games that use the EXT port and their usage
• Electrical pinout of the EXT port connector
• EXT Port joypad adapter (Player 3)

Availability of the EXT Port

General Notes

In general, some early Sega Genesis revisions (Genesis Model 1 revisions) will have the EXT port populated on the board fully installed, later revisions will just have a footprint (no EXT port connector nor filter caps), and even later revisions will have no footprint at all.

Those with a footprint can have a port and filter caps soldered back on to restore the functionality.

Those without a footprint may be able to have a port and filter caps soldered on via a hardware mod and daughterboard, if the console revision has an appropriate ASIC or GOAC chip that still has the EXT port (PCx) signals on the chip.

All other consoles other than the above cannot have an EXT port installed.

Models without a port but which utilize a Yamaha FC1004-based ASIC or Yamaha 315-5960 GOAC have EXT port signals available via a hardware mod. Those with Toshiba-based ASICs are unknown, and those with a Yamaha 315-6123(-01) GOAC cannot be modified.

Sega Genesis

Sega Genesis Model 1

Early Sega Genesis Model 1 motherboard revisions before the VA6.5 revision all have an EXT port installed into the console, except for the SPC-200/201R Rev. A (1992-1993, Korea) revision (VA4-based) which just has a footprint.

Board revisions VA6.5 and VA6.8 just have a footprint.

The VA7 revision varies in between regions:

• Japanese region - has port
• Taiwan region - just has footprint
• All other regions - no footprint

All variants of the VA7 utilize a FC1004-based ASIC, so those without footprints can be hardware modded to install an EXT port.

Sega Genesis Model 2

All Sega Genesis Model 2 revisions do not have an EXT port and thus will require a hardware mod if the chipset supports it.

The VA0, VA1/VA1.8, Korean SPC-1600R Rev. 0, and Korean SPC-1600R Rev02 all use a FC1004-based ASIC and thus can be hardware modded.

The North American VA2 and VA2.3 utilize Toshiba-based ASICs, and thus is unknown if they can be hardware modded.

The North American VA3 use a FC1004-based ASIC and thus can be hardware modded.

All regions of the VA4 utilize a Yamaha 315-5960 GOAC and thus can be hardware modded.

Sega Genesis Model 3

All Sega Genesis Model 3 revisions do not have an EXT port and thus will require a hardware mod if the chipset supports it.

All regions of the Model 3 VA1 utilize a Yamaha 315-5960 GOAC and thus can be hardware modded.

All regions of the VA2 utilize a Yamaha 315-6123 GOAC and thus can not be hardware modded.

Sega Genesis/Sega CD combo consoles

JVC Wondermega

The original Japan JVC Wondermega Victor RG-M1 and Sega HWM-5010 have an EXT port installed. These use FC1004-based ASICs.

The later Japan JVC Wondermega Victor RG-M2 and US JVC X'Eye do not have an EXT port. They use a FC1004-based ASIC and thus can be hardware modded.

Sega Multi-Mega/Sega CDX

All revision and regions of the Sega Multi-Mega/Sega CDX do not have an EXT port installed. They use a FC1004-based ASIC and thus can be hardware modded.

Aiwa Mega-CD/CSD-G1M

The Aiwa Mega-CD/CSD-G1M does not have an EXT port installed. It utilizes a FC1004-based ASIC and thus can be hardware modded.

LaserActive Sega PAC

The Pioneer LaserActive has 2 Sega PACs available: the PAC-S1 (Japan) and PAC-S10 (US). Both PACs do not have an EXT port installed. They utilize a FC1004-based ASIC and thus can be hardware modded.

Sega Genesis special models

Sega Nomad

The Sega Nomad does not have an EXT port installed. The only male DE-9 port on it is meant for Player 2 with a joypad; player 1's buttons are built into the console's face. It utilizes a FC1004-based ASIC (315-5700) and thus can be hardware modded.

Mega Jet

The Sega Mega Jet does not have an EXT port installed. The only male DE-9 port on it is meant for Player 2 with a joypad; player 1's buttons are built into the console's face. It utilizes a FC1004-based ASIC (315-5660-10) and thus can be hardware modded.

Sega Pico

Both Model 1 and Model 2 revisions of the Sega Pico do not have an EXT port and cannot be restored even with a hardware mod.

Sega Pico Model 1

The following are Sega Pico Model 1 revisions:

• Japan
  • HPC-0001
  • HPC-0003
  • Hirameki Mirai Kids IMC-001
  • HPC-0003A
  • HPC-0007
• US
  • MK49002

These revisions do not have a Genesis EXT port. They utilize a discreet chipset (no integrated ASICs), and thus cannot be hardware modded.

Do note that the Japan HPC-0001 has a male DE-9 port (Pico EXT) on the side; this maps to a separate I/O memory address to the regular female Genesis EXT port. The Japan HPC-0003 has a footprint only for the Pico EXT port (can be hardware modded). All other Japan and US revisions do not have a Pico EXT port.

I/O Ports:

• Pico EXT
  • Male DE-9
  • $800015 - Data port
  • $800017 - Control port
• Genesis EXT
  • Female DE-9
  • $A10006 - Data port
  • $A1000C - Control port

Sega Pico Model 2

The following are Sega Pico Model 2 revisions:

• Japan
  • HPC-0008
  • HPC-0009
  • Special releases
    • Pico Pocket Monsters
    • Pico Anpanman
    • Pico Mushiking
    • Pico Hamtaro
• US
  • MK49002

All Model 2 revisions do not have either a Genesis EXT or Pico EXT port. They utilize a Yamaha 315-6123 GOAC and thus cannot be hardware modded (no signals available on chip).

Yamaha Mixt Book Player Copera

The Yamaha Mixt Book Player Copera is a special variant of the Sega Pico (based on Model 1 HPC-0001 Pico) which adds various audio hardware, a Pico EXT port, and has its own library of enhanced Copera games.

The Copera does not have a Genesis EXT port. It utilizes a discreet chipset (no integrated ASICs), and thus cannot be hardware modded.

Computer-based

Amstrad Mega PC

The Amstrad Mega PC (with its Sega Genesis-based ISA card, the Game Processor Card/Issue Number 5) does not have an EXT port installed. It utilizes a FC1004-based ASIC (315-5487•) and thus can be hardware modded.

Sega Teradrive

The Sega Teradrive PC has an EXT port installed^[1]. This doesn't use any integrated ASICs (discreet chipset).

Arcade-based

Sega Mega Tech

The Sega Mega Tech (Europe)/Mega-6 (Japan) does not have a Genesis EXT port. They utilize a discreet chipset (no integrated ASICs), and thus cannot be hardware modded.

Sega Mega Play

The Sega Mega Play does not have a Genesis EXT port. It utilizes a discreet chipset (no integrated ASICs), and thus cannot be hardware modded.

Table summary

Hardware mods to restore the EXT Port

Consoles with unpopulated footprints

For console models/revisions without the EXT port installed but with a footprint left behind (no filter caps), just solder in a new right-angle female DE-9 connector and appropriate filter caps back onto the board. This includes various revisions of the Sega Genesis Model 1.

Consoles without footprints

Most consoles without an EXT Port footprint can be hardware modded to install an EXT Port and filter caps, depending on if the chipset includes an ASIC/GOAC with EXT Port signals still included (PCx lines) on the chip pins.

General wiring notes

To wire up a female DE-9 EXT port to the console from a compatible ASIC/GOAC chip, wire everything up as such.

Connect PCx lines from the ASIC/GOAC to an appropriate filter cap, then to the appropriate EXT port connector pin. Wire the center pins of all filter caps together and tie to the motherboard ground. Connector pins 7 and 9 will require pull-up resistors. Connector pin 5 goes to +5V VCC, and pin 8 goes to motherboard ground. See wiring schematic below for full details.

It is recommended to use 2200pF filter caps and 330 Ω pull-up resistors. The pull-up resistor value will vary between console revisions.

Yamaha FC1004-based ASICs

All of these have a similar pinout; use pinout notes from Sega 315-5487 ASIC.

^{[2] [3]}

Toshiba ASICs

Unknown; Toshiba pinout. It is suspected that the unknown pins on 72-78 or 190-200 may be the PCx and some VSS/VCC lines. Needs investigated.

Yamaha GOACs

The Yamaha FJ3002 (315-5960) can be hardware modded, while the Yamaha FQ8007 (315-6123) and G28007 (315-6123-01) cannot (no signals available).

Usage of the EXT Port

The EXT port was only ever officially used for the Sega Mega Modem in Japan for online networking services, direct-dial peer-to-peer online gaming, and for connectivity with some games to an online server. However, some games and homebrew apps will poll the port to use as a Player 3 joypad port (with appropriate adapter), as a 5V TTL serial port, or for other purposes.

Details on playing the direct-dial peer-to-peer based games online. It should still be possible to do so with a real phone landline, 56k modems, or with a DreamPi. The subscription/server-based games and application servers are all now defunct, so those can't be utilized online anymore.

Mega Modem software

• % = Modem support Japan region only; however, modem support can be accessed with a region switch mod or Game Genie code.

Player 3 Software

• % = If no devices are plugged into any joypad port (including the EXT Port), a controller test screen will be displayed

• %% = Diagnostic ROMs which can display Player 3 joypad data from the EXT Port. GenDiag can display the raw joypad bits, while SMJ Demo will display button presses on-screen

• %%% = ROM hack by GenesisDoes which has support for using any joypad port (Genesis P1, P2, P3 EXT; Sega Pico EXT, and Sega Pico internal pad) to control the player

Other software

• % = SDK software suite for creation of Sega Genesis chiptune music. Software and serial port software through the EXT Port to communicate between PC and Genesis for music composition

• %% = Has support for PS/2 Keyboard & Mouse, xPort UART (modem), 3-button Genesis controller, Mega Mouse, and Sega Saturn keyboard through the EXT Port

EXT Port connector pinout

The EXT port is a DE-9 connector like the Player 1 and Player 2 joypad ports, but gender flipped (female port instead of male). It's pinout is electrically the same as a regular joypad port; however, the pin ordering on each row of the connector is reversed.

See this Wiki entry for pinout

EXT Port joypad adapter (Player 3)

Wiring schematic

Joypad devices can be connected into the EXT port with an appropriate adapter. Some diagnostic ROMs can detect and run a joypad over the port, which can be useful for testing the functionality of an EXT port. Also adding native Player 3 support as a gameplay feature may be useful in homebrew game development.

Since the female port has its pin order reversed on each row compared to a Genesis joypad, the wiring just needs reversed.

EagleSoft Ltd. joypad adapter

GenesisDoes from EagleSoft Ltd. has created a EXT Port joypad adapter kit, which you can order from him or build a DIY kit.