I forgot to mention we're running at 40Mhz with 20ns SRAM. The EPROM is something like 70ns. So, running from EPROM would slow us down quite a bit.

Also, I must use the uCAN2 eval board "as is", so the address decoding scheme is fixed.

The 80C390 has 4KB on-chip SRAM that can be overlayed (code&data) so I can copy the loader there and start executing. The loader would then somehow move the application from EPROM to RAM. When SRAM is configured for overlay, its located at 0x00400000-0x00400FFF. I suppose this allows the lower 4MB of memory to be configured as desired for the loader to move things around. The problem I'm having is figuring out how to address such a high address. There's pages in the user guide which may explain things to someone who is familiar, but I'm having a heck of time getting it together in my head. Another thing is that I have no proper ROM debugger or emulator, so diagnosing problems or proving that what I've coded is working is difficult.

Anyone out there familiar with this beast?