CP/M load question

Hi at all, I'm sorry I'm not very prepared and my English is basic. I have a mainboard with CPU Z80 derived from the famous Ferguson Big Board 1 (that i have working fine). It has a CPU Z80A running at 4MHz, 64KByte DRAM, FDC 1797 with external data separator FDC9228BT. It equipped with its own BIOS that is loaded into memory at address F800H but it not has the operating system CP/M. If instead of his eprom i insert the firmware coming from Ferguson Bigboard 1 (which is loaded into memory at address F000H) that has FDC 1771 it run properly loading the operating system CP/M 2.2. I looked in my experience and modified the CP/M loader and CBIOS to point at the entry points of the bios at F800H, so the loader loads into memory correctly ALL the CCP, the BDOS and CBIOS, but it not complete the boot CP/M with the prompt (the error that comes to me is: track 2 sector 1 not found. it is an area where normally there is no CP/M code and that it is regularly read with a simple read command available from the firmware). I ASK FOR: Anybody has any idea? Is there a Z80 emulator where I can load the BIOS and i can try to load the operating system CP/M to see what type of problem? Regards Enri