Genesis:Mega Nomad

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The ultimate switchless mod for LCD modded Nomads! Based on the Sebastian Kienzl’s code.

The Mega Nomad

Features

  • Correct frequency carrier for PAL – No more black/white picture when in 50HZ (PAL). Precise frequency for quality PAL color picture.
  • Switchless mod – change region / video modes via the Mode button.
  • LED indicator – 3 color external LED shows the current mode (Green – EU, Red – JAP, Orange – US). It is placed additionally in the console.
  • Works great with the TV out cable – play your games in PAL/NTSC or any region on your TV via the original cable! (your TV must support composite PAL/NTSC)

The kit contains:

  • 1 x Mega Nomad v1.0 board
  • 1 x 3 color LED
  • LCD display and LCD driver board are NOT INCLUDED in the kit!

Mode Button

  • Short press <250ms – normal console reset
  • Long press between 250ms and 1250ms – 50/60 Hz on-the-fly switch (after button is released the LED flashes slow – 50Hz or fast – 60Hz)
  • Hold for more than 1250ms – As long as the button is pressed, the regions are cycled through (1sec each). After the button is released the region-setting gets changed and the console will reset so the new region-settings take effect.

All settings are stored in the internal memory, so after console reset it will remain in the last set mode.

Here’s a demo of how this board works in a LCD modded Nomad:

This LCD is recommended for the mod, it has a blue driver board PCB. You can find it on ebay, just use "3.5' LCD TFT rear camera monitor" etc. keywords. However, any replacement LCD should be compatible, but you may to test them through the TV out before putting them in the console. Just mod the console with Mega Nomad and test the LCD externally with the original Sega composite TV cable.

Nomad-basic-lcd-replacement.jpg

It's also good to have the LCD board modded to use 5V instead of 12V to save battery power (Method 2 on this page)!

Installation

  1. Disassemble the console. The pictures below should be sufficient enough to have the console modified with Mega Nomad board. You can also check this page for reference on how to open the console.
  2. The mod board looks like this on the back:
    Meganomad Board exp.png
    You can test the LED with a small 3V button battery to see which pin is red and which is green.
  3. You must first install the new LCD screen and have it working before adding the mod board. Make sure it’s centered properly before gluing! It should look something like this:
    Meganomad screen install example.JPG
  4. Take composite video signal from here if needed by your replacement screen:
    Meganomad-composite.JPG
  5. Drill a small hole just above the E letter on the GENESIS label in front. This is for the status LED install.
    Meganomad led install.jpg
  6. You can take some of the front material of the LED before you hot glue it so it would stay levelled and be easier for gluing. Solder the wires and hot glue it in place.
    Meganomad-led-prepare.jpg
    Meganomad led install back.jpeg
  7. Solder the wires on the other end to the mod board LED pins.
  8. Solder wires for 5V VCC and GND:
    Meganomad vcc ground.jpeg
  9. Make a small cut right next to C232 where the small via hole is. The trace should be cut between the C232 and the hole. This is necessary to have the original NTSC source clock isolated from the CXA encoder.
    MegaNomad NTSC clock.JPG
  10. Carefully solder a wire on the right side of C232, this wire will go to TSC_IN on the mod board.
  11. Place insulation tape on the mod board oscillator to prevent shorts when gluing:
    Meganomad-tape.JPG
  12. If you prefer you can hot glue the mod board to the main board now or do it later. It's recommended to do this later after verifying functionality. Place it exactly as shown on picture. It’s designed to fit just below the 6 buttons.
    Meganomad-position.JPG Meganomad-position2.JPG Meganomad-position3.JPG
  13. Flip the mainboard and locate the Sony CXA encoder chip and cut the trace going to pin 7 as shown on the picture. Solder two wires to pin 6 and pin 7 on the chip as shown. Pin 6 goes to LK_OUT and pin 7 goes to _P7 + JP3/4 on the mod board.
    Meganomad cxa.JPG
  14. Next we go to the other mainboard of the console. Solder a wire to the RESET pin here:
    Meganomad-reset.JPG
  15. On the other side of the second mainboard you’ll find JP1/JP2 and JP3/JP4. Cut any traces between JP1/2 and JP3/4 as shown. Solder wires to the shown points, be careful not to short anything.
    Meganomad-jp1.JPG
    Meganomad-jp3.JPG
  16. These jumpers are for controlling the region and 50/60HZ modes on the console. When you assemble the second mainboard with the plastic cover you should have 3 wires coming from it:
    Meganomad-wires-ribbon.JPG
  17. The last wire comes from the MODE button on the console. Mode and start buttons are on a separate PCB connected with a 3-wire jumper cable. Solder a wire to either end of the cable, to the middle pin (MODE).
    Meganomad-mode.jpg
  18. This wire goes to MODE solder point on the mod board.
  19. At this point, you should have all wires soldered to the mod board. Note that you have two wires going to the same solder point _P7 + JP3/4 on the mod board.
  20. When you’re ready test everything before putting it back together. Make sure that every feature works as expected.