Information on the CD32 main board
Some information comes from the CD32 service manual..
The system consists of a 4 layer PCB for the main board and 2 additional PCBs, one for the Audio/LEDs and one for the CD-ROM drive.
The motherboard for the Amiga CD32 is roughly 6" by 12" and is a four layer board. On the main PCB - is a 14MHz 68EC020, the AA chipset, an ASIC called Akiko, a DAC for playing standard CD audio, and a small amount of EEPROM.
Akiko is a 160-pin PQFP surface-mounted device containing most of the remainder of the logic necessary m the Amiga CD32. It includes the CD-ROM control logic and the system timers. The EEPROM is 8K bits, and designed for storing Settings, high scores, bookmarks, etc., on the Amiga CD32.
In addition to the AA chips, Akiko, the CPU and the EEPROM/ the main board contains 2MB of DRAM as Chip RAM. A PAL or NTSC modulator is also included on the main board.
The Compact Disc DAC is a standard 18-bit, 8x oversampling DAC. Along with the superb audio quality of the DAC, the Amiga CD32 expansion connector has digital audio input capability in order to mix an external source such as MPEG audio with the CD audio and Amiga audio.
There were two released version of the PCB, version 3 was the standard PCB for PAL/NTSC machines. A special version 4 PCB was made for the French market (they use a SECAM TV system) The only difference between the two types is the video encoder.
It is reported that the On/Off switch is from the old C64 production line and is liable to cause problems, see the CD32 PSU page for more information.
Updated 27 September 2020