CD drive



The part that makes you wait and fails in CD systems. The ones used in the NeoGeo consoles are very similar to those found in the Sega CD. They're basically enhanced audio CD drives, which are also able to read CD-ROM data tracks.

Made of a control board and an optical pickup.

The NeoGeo CD top-loading model drive was made by Sony. The CDZ one was made by Sharp ?

The control board has:
 * A 4-bit mask ROM MCU (Sony CXP5084), taking care of operation sequencing and communication with the NeoGeo.
 * A DSP (Sony CXD2500) to process analog data from the pickup.
 * A servo controler (Sony CXA1372) to drive the pickup coils for tracking and focus.
 * A spindle, sled (and tray) motor driver.

=Connections=

Some say the protocol was standard for the time, but clear information is hard to find. This was guessed from the system ROM disassembly, Sega CD documents and a logic analyzer.

Top-loading model
Connector pinout, directions are from CDD (CD Drive) to CDC (CD Controller):

Missing: /RESET, C2PO, and 16MHz.

Front-loading model
Connector pinout, directions are from CDD (CD Drive) to CDC (CD Controller):

Adjustment pots
To do !