[JohnBHanson]

Interesting - I have not got the whole answer but somethings helpful (maybe).

I cannot identify the first 4 sectors. After that it looks like a gemini boot sector and
ccpz/bdosz/bios.

This bios is for the xebec controller and also hard disk. The bios issues a init_drive_characteristics command to the xebec controller. This was not included in the emulator so I have added it - although the parameters are ignored!. What this command is used for is to specify the mapping between logical blocks in the scsi world to CHS format in the hard disk world.

Having added this extra command I discovered that a ram-disk card is also required a gm833 so this has been added along with a serial port.

I suspect that it is not booting now because I don't have a hard disk image. However below is the config file I have used to get this far.

#verbose

cpuclock 4

board 0xfe gm813_mmu

board 0xb0 gm832 Gemini green
board 0xb8 serial_8250 trace tty tty /dev/ttyS0

board 0xe0 gm849_scsi ~/beaver/disks/gem925.dsk
board 0xfb gm833
board 0xe0 gm849_floppy -geometry S35.2.10.0.512

binload cb00 ./beaver/network/cpm64w.bin

byte 0 c3 00 eb


I hope that helps a little. PS - you need to download the latest xbeaver with command 0x0c added.