Sega Mega-Tech Arcade

📄 Schematics (Sega Mega-Tech)

Schematics & Manuals 📎 Megatech-schem.pdf (file unavailable) 📎 MegaTechSystem_UK_Manual.pdf (file unavailable) Monitor...

Hardware Overview (Sega Mega-Tech)

The Sega Mega-Tech was produced by Sega in 1989. It is a cartridge-based multi-game system arcade cabinet. The Sega Mega...

📄 Boot Up Behaviour (Sega Mega-Tech Arcade)

Applying 5V to the 5V rail should get the Mega Tech booting up. Power draw should be around 1.8 to 2A. The top monitor ...

Mega Drive Overview (Sega Mega-Tech)

The Mega Drive circuit is on the left side of the board, and is mostly made up of the following chips: 68000 CPU (Motoro...

Powering From Bench (Sega Mega-Tech)

The Sega Mega-Tech is powered from the pin headers at the top right . It has two main rails:- a 12V rail for the ...

Master System Boot (Sega Mega-Tech)

There is only really one main stage of boot on the Sega Mega-Tech and that is to get the system operational after readin...

Mega Drive Circuit (Sega Mega-Tech)

Here are some useful pin diagrams and details for checking parts of the Mega Drive System 315-5313 (VDP) The 315-5313 is...

Mega Drive Boot (Sega Mega Tech)

Just like a normal Mega Drive, you will need a game installed to actually boot and show anything on screen. If the SMS ...

Mega Drive 68k (Sega Mega-Tech)

If you are suspecting issues with the Mega Drive system and want to check the 68k operation, this guide will take you th...

Mega Drive Z80 (Sega Mega-Tech)

If you are suspecting issues with the Mega Drive system and want to check the Z80 operation, this guide will take you th...

Mega Drive AV Out (Sega Mega-Tech)

You can probe the CN8 connector (RGB1) for the main game screen. You will get no output until a valid game is inserted,...

Cartridge Pinout (Sega Mega-Tech)

The Sega Mega-Tech cartridges have a different pinout than the Mega Drive. The A side is identical, but the B side is di...

Reading Game Titles (Sega Mega-Tech)

Once the SMS reads the BIOS and boots, it instructs the Mega Drive to read all games header ROMs that are inserted. The ...

Mega Drive Game Load (Sega Mega-Tech)

Depending on which game you insert, the 68k and Z80 come out of reset differently. Choose a Mega Drive game like Sonic T...

Master System Game Load (Sega Mega-Tech)

Depending on which game you insert, the 68k and Z80 come out of reset differently. Choose a Master System game like Afte...

Z80 Data Sharing (Sega Mega-Tech)

The two Z80s, one from the SMS and one from the Mega Drive, communicate with each other through a few buffers (IC13, IC1...

Audio Circuit (Sega Mega-Tech)

The audio circuit on the Sega Mega-Tech is identical to the Mega Drive, except for the final stage. Check out the Sega M...

📄 Coin Meter (Sega Mega-Tech)

When the Sega Mega-Tech boots up, the SMS system first disables the controller inputs on the Mega Drive by sending the I...

Button Interface (Sega Mega-Tech)

The IC24 I/O Expander connects the SMS Z80 data pins through to the CN2 (Select Buttons) and CN4 (Player 1 buttons), via...

Port Expander IC24 (Sega Mega-Tech)

The IC24 I/O Expander CXD1095 connects the SMS Z80 data pins to various places, including the YM2612 sound IC, buttons a...

Test Mode (Sega Mega-Tech)

Test mode can be entered only when there is at least one valid game in the slot, otherwise pressing the button does noth...

No Game Load (Sega Mega-Tech)

After you get game title data displaying on the Menu, you still may not get game load output on the Mega Drive AV Out (C...