Couple of things to note. Most of the IC's are off the shelf products. However the large black in the upper left with the white sticker is a custom DSP built just for the MPC. The other IC about the same size is from NEC (no details yet).
The left connection is the angle piece for the flash ROM. The FLASH ROM board is too tall for it to stand upright inside the case so this is here. The right connector is for the EB16 effects.
From top left to bottom right: 8-out expansion, internal floppy, internal IDE/ATAPI then internal SCSI. Just above the SCSI connector is the slot for the SMPTE chip (Note this is the same chip in the MPC2000 SMPTE option). The IC to the left of the SMPTE socket and the IC on the lower right make up the internal SCSI controller.
Flash Boot ROM:
It's an Intel E28F800. MPC's operating system storage(?).
Empty Socket for ROM:
This is possibly for a Boot ROM (not used). The jumper just above it selects whether to boot from the Flash BOOT ROM or a ROM installed here.
This is a 2 position jumper labeled: BOOT BLOCK. The selection is BOOT LOCK or BOOT LOCK BLOCK. (Factory default is BOOT LOCK). I have some notes from IceCool about this here.
6 pins connector that has only 2 of the pins with circuits run to it. The two pins connect to IC220 and IC40. Both are manufactured by XILINX and are 178 MHz CPLD's (model XC9572). One's labeled CPU and the other WRAM. These type are circuits are usually mounted then programmed at the factory. (which may explain the pins)