User Summary
The 3 button Genesis controller is basic controller originally released with Genesis and Mega Drive. The controller has 3 play buttons (A, B, & C), a D-Pad, and Start button.
The controller utilized three different D-Pad designs. The early ones used an internal plastic nub that tended to wear out. The middle ones used a metal ball bearing that did not wear out easily. The final ones that were released used a two part D-Pad mechanism. This type also tended to wear out over time.
Official Controllers
Below are main differences between the controller models:
Japan
SJ-3500
ABC Buttons - Red
Stat Button - Blue
D-Pad Arrows - White
Text - SEGA Computer Video Game Control Pad
D-Pad Internals - Plastic
North America
Model 1650 v1
ABC Buttons - Red
Start Button - White
D-Pad Arrows - Red
Text - Sega Genesis
D-Pad Internals - Plastic
Model 1650 v2
ABC Buttons - Black with no coloring
Stat Button - White
D-Pad Arrows - White
Text - Sega Genesis
D-Pad Internals - Ball Bearing
Model 1650 v3
ABC Buttons - Black with no coloring
Start Button - White
D-Pad Arrows - White
Text - Sega Genesis
D-Pad Internals - 2 Part Plastic
Europe
Mega Drive v1
ABC Buttons - Black with no coloring
Start Button - White
D-Pad Arrows - White
Text - SEGA Mega Drive Controller Pad
D-Pad Internals - Unknown
Mega Drive v1.1
ABC Buttons - Red
Start Button - White
D-Pad Arrows - Red
Text - SEGA Mega Drive Controller Pad
D-Pad Internals - Unknown
Mega Drive v2
ABC Buttons - Black with no coloring
Start Button - Red
D-Pad Arrows - White
Text - SEGA Mega Drive Controller Pad
D-Pad Internals - Unknown
Brazil, Asia, & South Korea
Super Aladdin Controller
ABC Buttons - Red
Start Button - Blue
D-Pad Arrows - White
Text - SAMSUNG Computer Video Game Control Pad
D-Pad Internals - Unknown