The board can decode any I/O port and of course RAM/ROM cycles. As it use a Pico2, its RAM is doubled vs Pico1 and it can access a 8MB PSRAM as well.
Advantage of this model is on The PicoCPC does NOT use of CH376 for USB : USB in FAT32&extfschip, everything is done with the Pico itself. PicoCPC handles FAT12, 16, 32, ExtFS. CH376 will be emulated, with nothing to do at the CPC side.
There is no external ROM, so the microntroller access the emulated RAM/ROM and USB/MicroSD at the same time: Direct write from the uSD to the CPC emulated RAM at 3MB/s (For example).