I have added a 74373 into the Quartus 2 BDF on the inputs of the 74245. And yes - it grabs the first 8 bits of the address.

I have even placed a 0x90 opcode for the processor to read - and at least, it looks like it now starts from the reset vector.

The top bits of the address - gonna connect these afterwards. Hopefully it's the 0xFFFF0. :)