At this point everything that as initially targeted is working. 

• Grant's stock Monitor and NASCOM BASIC code are running (call this BIOS in this case)
• Programs can be dropped on Host terminal screen and downloaded at full (possible) speed over USB
• All communication is over USB
• SIO emulation by the PSoC works with Grant's code (not in the most general case, but a good start)
• Front Panel works for examining and altering memory as well as running the program in ROM
• and also can be accessed from the Z80 IO space as IN, OUT instructions (INP, OUT in BASIC)

The things which are not yet done are; CF card support and support for the MCP23017 I2C Port Expander. Also, no other build was tried.

Grant's code supports a Compact Flash (CF) card with hardware connections. Board has a header with 4 PSoC pins and Power/Ground. This could be connected to an SDHC or SD card and used in SPI mode. This would require understanding how Grant's code accesses the CF card.

The MCP23017 could emulate a PIO chip (at least to some degree). The only issue is that the PIO has support for handshake lines and the MCP23017 is just two 8-bit data ports. But the PSoC could easily do bit banging. Having some degree of emulation would be a useful goal but it might help to have some target application (BIOS)