Main CPU

• Motorola 68000 @ 12.5 MHz (Same as the Genesis... runs in parallel with it... except the Genny CPU runs at the slower clock speed 7.9 MHz)

Graphics Processor

• Custom ASIC

RAM

• 6 Mbit Main RAM
• 512 Kbit PCM Waveform Memory
• 128 Kbit CD-ROM data cache memory
• 64 Kbit Internal Backup RAM

Colors

• Originally 64, same as Genesis
• Using programming tricks, can get 128 colors via HAM ("Hold and Modify")
  • Originally developed on the Commodore Amiga to boost color capabilities
  • Basically a graphic over a graphic = a double-color
• Using Cinepak and TruVideo:
  • 128 to 256 colors
  • Increase screen size from 1/4 to full
  • Advanced compression scheme, used in Win 95
  • Software-based upgrade
• Eternal Champions CD uses 256 colors simultaneously (only game to do so)

Storage capability of a Sega CD

• Approximately 500 MB of data (62 min of audio data equivalent)
• 1/4 screen B/W footage video: 1.5 to 4 hours
• 1/4 screen color footage: 45 minutes
• Above specs are prior to compression

Transfer rate of Sega CD

• 150 kbytes/sec (Single Speed)

Boot ROM

• 1 Mbit, contains:
  • CD Game Bios
  • CD Player Software
  • CD+G Software

Bios versions

• When you start the Sega CD, the title screen displays the Bios version in the upper-right corner of the screen. This helps identify what machine version you are using and in a way the security capabilities. (Startup music and startup screen of the Sega CD is different for each Bios)
  
• Bios Version
  • 1.00 Original Mega CD
  • 1.10 Original Sega CD, Motorized Drive
  • 2.00 Mega CD2
  • 2.05 Sega CD2
  • 2.10 Sega CD2

CD Access time

• 800 ms

Sound Circuitry

• PCM Sound Source
  • Stereo, 8 channels
  • 32 KHz Maximum sampling wavelength
  • 16 Bit D/A converter
  • 8X internal over-sampling digital filter
• Audio characteristics
  • Frequency Range: 20Hz - 20 KHz
  • Signal-to-Noise Ratio: >900dB@1K
  • Channel Separation: >900dB
• Output: RCA Pin Jack x2 (L/R)

Dimensions

• 301mm (w) x 212.5 (d) x 112.5 (h)

Weight

• (Sega CD1): 3.1 lbs / 1.4 kg