Genesis:Sega CD Model Differences

Page content & researching taken from io55.net's Genesis Add-Ons page with permission, in collaboration.

Models

Models are arranged chronologically. There are no revisions.

“CD (Model 1; mechanical tray)” (1992?)

The slightly less robust Sega CD, mainly in being less reliable (capacitors and the CD tray). Installs to the bottom of a Model 1 Genesis, with a front-loading drive mechanism prone to failure. The Model 1 will work with a Model 2 Genesis, but it will require expansion plates and screwing.

“CD (Model 2; top loader)” (1993-1996)

The somewhat more robust Sega CD, mainly in being more reliable (definitely CD tray, maybe capacitors). Installs to the side of a Model 2 Genesis, while being supported by both the side and bottom. The Model 2 will work with a Model 1 Genesis, but it will require expansion plates and screwing. Units with a model number ending in “A” are made in Japan, rather than China.

References

https://en.wikipedia.org/wiki/Sega_CD

https://gametrog.com/sega-cd-model-1-2-information-specs/

https://gametrog.com/how-which-sega-cd-system-do-i-have/ (howto tips)

https://www.reddit.com/r/SEGAGENESIS/comments/8w7fpa/model_1_or_2_sega_cd/

https://gametrog.com/how-to-connect-hook-up-sega-cd-1-front-loader-to-genesis-model-2/ (M1 CD on M2 Genesis)

https://gametrog.com/how-to-connect-hook-up-sega-cd-2-clam-tray-loader-to-genesis-model-1/ (M2 CD on M1 Genesis)