This guide will show how to install a switchless region mod into a Sega Mega Drive model 2 games console for region free and 60Hz full speed, full screen gaming. This guide is compatible with switchless region PIC codes from D’force3000 (D4S) and Borti4938 and covers model 2 revisions VA0, VA1 and VA4.
Solder Maps (VA0 / VA1 / VA1.8)
Reset Line, Video & Language (VA0 / VA1 / VA1.8)
There are no pads of jumpers on the Mega Drive 2 VA0-VA1 for these connections which makes this install more difficult than an MD1 region mod. The Reset Line, Video, and Language connections need to be made to either the traces or the IC pins.
Cutting Traces and Solder Mask Removal
The best way to do this is to use the tip of a scalpel whilst viewed under magnification. It is best to scrape the solder mask from the trace along the length of the blue line in the image. This will reveal a greater area of copper that will allow a better soldered connection. The trace should be shiny which will show that the correct amount of solder mask has been removed.
Soldering to the Pins
Alternatively leave the traces unscraped and instead solder to the chip pins. Pins 46, 78 and 107. This method will require 30awg solid core Kynar wire and there is greater potential for damage. This is much more difficult and requires very fine soldering skills as it is easy to bridge the pins of the IC. There are two options.
- Lift the pins from the board and solder to them. Do not cut the three traces.
- Leave the pins connected to the board and solder to them. Cut the three traces.
Lifting pins will mean there is no permanent alteration to the Mega Drive 2 so might be the preferred method for purists, but the risk of breaking the pins is high.
CPU Halt (VA0 / VA1 / VA1.8)
- CPU Pin 19
When this is connected the game will pause when START+A+B+C is held long enough to start cycling through the console’s regions. Only connect this if you want the game to pause when
cycling through the regions.
Solder Map (VA4)
Video & Language (VA4)
Video and language are hard set on the VA4 by two zero ohm resistors soldered across some jumpers. On the PAL board the jumper for Video will be connected to Ground and the jumper for Language will be connected to +5V. By removing these zero ohm resistors we can control the video and language, which determine the region of the console, with the modchip.
(DIAGRAM OF JUMPERS AND REGIONS)
In order for reset to be controlled by the modchip a trace cut is necessary. There are two options for this and both come with their own problems and benefits.
1 – Top trace cut and solder mask scrape.
This requires that solder mask is removed from the thin trace and then a wire soldering to that exposed trace. This is sometimes more difficult than it sounds and is one extra thing that is permanently altered on the console.
(IMAGE OF ALTERNATIVE RESET METHOD)
2 – Bottom trace cut and soldering direct to the button leg.
This requires that a trace is cut on the bottom of the board and a wire is then soldered directly to the button leg. Soldering to the leg requires more heat and it is possible to permanently damage the button if you are not careful. Also flux can get inside the reset button which can cause random resets. Try use little solder and do it quickly. The benefit is that only 1 permanent modification is required.
(IMAGE OF MAIN RESET METHOD)
LED (VA0 / VA1 / VA1.8 / VA4)
There are two types of LED solder points on the model 2 Mega Drive. Some are through hole plated with a solder pad on the top and bottom layers. The other type is not through plated and only has a pad on the bottom of the board. When pushing the LED through this second type there is a great risk that the pad on the underside can lift and tear off. Be careful when threading the LED.
The LED will need soldering into the original ground hole on the Mega Drive mainboard labelled COM. For this reason a common cathode LED is used for Mega Drive 2 region modding. The common LED pin will need bending in a specific way in order for the common pin to line up and centralise the LED to the location of the original LED, this requires two bends. One straightening the pin outwards and a second bending the pin downwards. The two outer pins will need bending at right angles opposite to the common pin and wiring to the LED OUT pins on the modchip.
The LED or the wires will not move once in place so there is no need to add heatshrink tube to the LED pins for strain relief.
Diffuser (VA0 / VA1 / VA1.8 / VA4)
Depending how the LED pin bends were made, the new LED might not fit below the diffuser. In this case some material will need removing from the diffuser. A rotary tool is best for this task. In order to avoid this, make sure the LED pin bends are tight and flush to the LED bulb.
Controller C6 & C9 (VA0 / VA1 / VA1.8 / VA4)
- C6 to Controller Port Pin 6 which detects when A+B is pressed.
- C9 to Controller Port Pin 9 which detects when C+Start is pressed.
To get the wires to the bottom of the board for soldering these points you can go through the controller connector case. Threading the wire from the bottom of the board to the top through the connector is the easiest method for this.
(IMAGE OF WIRE THREADED THROUGH CONNECTOR)
Alternative Controller Points
Alternatively you can scrape solder mask off two vias on the top of the board for soldering the wires. This requires a permanent modification to the board and is very fine soldering which some might find difficult.
(IMAGE OF ALT SOLDER POINTS)
Power and AV Socket Fix (VA0 / VA1 / VA1.8 / VA4)
Whilst the console is open it is a good idea to check that the solder connections on the bottom of the board for the sockets are intact.
If not, apply some new solder and heat the connection until they flows and become whole again. More often than not, they are broken and need resoldering
Jumpers / Special Pins (J1, J2)
Depending on the board revision or code used, these jumpers & special pins might not be available.
J1 / Pin 4 (Borti4938 Code) – Reset On Mode Change – When set to (+) or a +5V source, changing the region via the reset button or controller will have an instant affect on the video rate. When set to (-) or ground, changing the region via the reset button or the controller will reset the console and the new region will be set on boot up.
J2 / Pin 7 (Borti4938 Code) – Set LED Type – When set to CA or a +5V source, a Common Anode LED should be used. When set to CC or Ground, a Common Cathode LED should be used.
Program Your Own
If you want to make this yourself you can get the codes from the following links.
- Official web page with the download http://www.dforce3000.de/?uid=12
- Wayback machine https://web.archive.org/web/20191201071610/http://www.dforce3000.de/?uid=12
- Borti4938’s Mega Drive switchless mod project page at GitHub https://github.com/borti4938/Switchless_SEGA_MasterSystem_MegaDrive/tree/master/MD_Switchless
Still need to find and add the CPU Halt location (VA4).