Sega Mega-CD I (Sega CD I in North America)
Sega Mega-CD II (Sega CD II in North America) had a faster CD-ROM
drive
JVC Wondermega (Xeye in North American release, never released in
Europe), was a all-in one Sega CD unit
Sega Multimega (named Sega CDX in North America)
Pioneer LaserActive Sega CD module, an add-on device you could add
to a Laseractive Pioneer Laserdisc player.
What it adds to the Megadrive:
10 extra sound channels to complement the sound from the Megadrive
Z80 sound processor.
sprite enhancement features such as scaling and rotation, similar to
that of the Super Famicom/SNES Mode 7.
Specs: Main CPU: Motorola 68000 @ 12.5 MHz
Same as the Megadrive... runs with it... except the Genesis 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
Colours:
Originally 64, same as Megadrive
Using programming tricks, can get 128 colors via HAM "Hold and
Modify"
Using Cinepak and TruVideo:
128 to 256 colours
Increase screen size from 1/4 to full
Advanced compression scheme
Software-based upgrade
Storage capability
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 (1X) Boot ROM:
1 Mb contains:
CD Game Bios
CD Player Software
CD+G Software
Bios Version Machine
1.00 Original Mega CD
2.00 Mega CD2 (Sega CD2 in North America)
2.05 Mega CD2
2.10 Mega CD2
2.21 Sega Mega LD (Japan), Sega Multimega (Europe) (CDX in North
America)
Access time: 800 ms Sound Circuitry:
PCM Sound
Stereo: 8 channels
32 KHz Maximum sampling wavelength
16 Bit D/A converter
8X internal over-sampling digital filter
Audio:
Frequency Range: 20Hz - 20 KHz
Signal-to-Noise Ratio: >900dB @ 1K
Channel Separation: >900 dB
Output: RCA Pin Jack x2 (L/R) Dimensions: 301mm x 212.5 x 112.5
Weight: 3.1 lbs