Sega Model 2A CRX and Model 3 Step 1.0 Differences and Similarities

At this point I own both Sega Model 2A CRX with Virtua Fighter 2 and Sega Model 3 Step 1.0 with Virtua Fighter 3. Both of these games were the marquee game for their original hardware revision and it only got better after that. Later steps and revisions had faster processors and more horse power. Having these to pieces for a few weeks now I have noticed a few things that are quite similar and some things that are very different between the two. So here they are:

Similarities:

• Made up of 3 Boards (Graphics, CPU, Rom)
• Both use Martin Marietta/Lockheed Martin Real 3d Chips
• Use the same 25 Pin input connector
• Display video in medium resolution (24kHz)
• One power connector matches (10 pin ground & +5v)
• Board stacks in metal cases fan cooled
• Use the same Video (5 pin) and Audio (4 pin) Connectors
• Output unamplified audio (Amplifier or Amplified Speakers needed)
• Socketed roms make for easily upgrades (VF2.1/VF3TB)
• Earlier games do not use security boards (Later games like DOA do)
• Neither game got an arcade perfect port (same goes with the first 4 games)
• A Model 2 will work in a Model 3 Cabinet as long as you connect the 24 Pin to the proper pins

Differences:

• Model 2 uses an Intel cpu (i960), Model 3 uses a PowerPC cpu (603e)
• Model 2 uses another 10 pin (+5v & ground), Model 3 uses a 24 pin for more power (+3.3v, Ground & +5v)
• Virtua Fighter 3 uses an additional button (pin 12 on model 2 harness)
• Model 2's fan connects externally, Model 3's fans (2) are internal and connect to the filter board
• Some Model 3 Boards (like mine) have a vga port right on the filter board
• A Model 3 will not work in a Model 2 Cabinet without a different power supply (one with +3.3v)

Sega Model 2a Board (with cage and filter board


Sega Model 3 Step 1.0 Board