X68000 Non-Custom Chips
Function Part # Manufacturer Notes
Real Time Clock
 RP5C15 Ricoh
Sound:
FM Synth
 YM2151 Yamaha Paired with YM3012 DAC. 8 note, 2 channel, noise
Sound:
ADPCM
 MSM6258 Okidata Also used in the PCFX
FDD Control
 72065 NEC
HDD Control
 MB89352A Fujitsu SCSI HDD Controller (Super, XVI + X68030)
Peripheral: Serial
 z85C30 Zilog Dual channel Serial controller. 1 for RS232, 1 for Mouse
Peripheral: Printer
 8255 NEC Printer port, joystick ports.
DMA Control
 HD63450 Hitachi DMA I/O for FDD, HDD, Expansion Slots, ADPCM Audio
MFP
 68901 Motorola Multi Function Peripheral controller. Controls monitor sync, Serial port, real-time clock, soft-power, FM Synth, IRQ, keyboard
Math Co-Pro
 MC68881 Motorola Optional. XVI has a socket for it, older units require an add-on board (often combined with RAM expansion)

Source: NFG Games + Inside X68000, SoftBank 1993