Sega's Genesis also known as Mega Drive was one of the two rivals of it's time(the other being the SNES). The Genesis also had two addons, the 32 bit extension called 32X and the CD-Rom drive called Mega CD.

Specs:

• CPU: Motorola 68000 at 7.61 MHz
  - 1 MByte (8 Mbit) ROM Area
  - 64 KByte RAM Area

  Co-Processor: Z80 @ 4 MHz (Not Present in MK-1631)
  - Controls PSG (Programmable Sound Generator) & FM Chips
  - 8 KBytes of dedicated Sound Ram

  Graphics:
  - 64 simultaneous colors of 512 color pallete.
  - Pixel resolution: 320 x 224
  - VDP (Video Display Processor)
  - 3 Planes: 2 scrolling playfields, 1 sprite plane

  Sound:
  - PSG (TI 76489 chip)
  - FM chip (Yamaha YM 2612)
  - 6-channel stereo
  - 8 KBytes RAM
  - Signal/Noise Ratio: 14dB